Deficit Irrigation

Bihar), India. This experiment was undertaken to study the response of different levels of irrigation on crop growth, yield, biomass and water use efficiency of Rabi maize under different levels of furrow irrigation under different treatments. The experiment was laid out in randomized block design with four treatment, five replication and five irrigations were applied in the main plot. The growing season was divided into three phases: vegetative, flowering and grain filling. The irrigation treatments consisted of all possible combinations of full irrigation or limited irrigation in such that T 1 (full/control irrigation), T 2 (75% of CI), T 3 (50% of CI) and T 4 (Rainfed /No Irrigation). The biometric parameters like plant height, stem diameter, number of leaves and canopy spread were significantly superior in treatment T 1 (control/full irrigation) compared to other deficit irrigation and rainfed treatments. The biometric parameters like plant height, stem diameter, number of leaves and canopy spread for treatment T 1 (control/full irrigation) was 179.80 cm, 29.90 mm, 12 and 87.70 cm respectively. Rabi maize yield was highest for treatment T 1 with a value of 11.12 t/ha, followed by treatment T 2 (75% of CI) with a value of 10.98 t/ha and lowest for treatment T 4 (Rainfed) with a value of 3.35 t/ha. Biomass was highest for treatment T 1 (CI) with a value of 24.92 t/ha, followed by treatment T 2 (75% of CI) with a value of 24.65 t/ha and lowest treatment T 4 (Rainfed) with the value of 7.931 t/ha. The crop yield and biomass were significantly higher for treatment T 1 (control/full irrigation) compared to other treatments. The water use efficiency of Rabi maize yield decreased with increase in irrigation level for all treatments of furrow irrigation. Water use efficiency was highest for treatment T 3 with a value of 310 kg/ha-cm followed by treatment T 2 with a value of 303 kg/ha-cm. The water use efficiency was significantly higher treatment T 3 (50% of CI) compared to other treatments. The adapted values of canopy growth coefficient and canopy decline coefficient were 15.4% day -1 and 9.5% day -1 respectively for Rabi maize. The days of emergence, sowing to flowering, senescence and maturity were 6, 60, 142 and 161 days respectively. The adopted values of water productivity (WP) were obtained as 30.7 g m -2 . The harvest index was obtained as 48%.

In search of techniques to reduce irrigation water use in the Ogallala Aquifer region, several deficit irrigation techniques were evaluated in corn and cotton production. Several iterations of deficit irrigation (based on ET), including partial root-zone deficit (PRD) and regulated deficit irrigation (RDI) treatments, were implemented in the 2021 and 2022 summer season. Corn and cotton did respond to the different deficit irrigation treatments. Significant yield advantages were observed in fixed PRD on both crops while RDI also showed some yield advantage for corn.

Investigating effective methods in agricultural water management could be a potential solution to address the water scarcity issue and its consequences in the economy of semi-arid regions. A study was conducted in 2023 to identify the benefits of different irrigation technologies and irrigation water management strategies for cotton production in western Kansas. Effects of two configurations of the new mobile drip irrigation (MDI) system (1 gal/h and 2 gal/h) on cotton yield and yield components were compared with a LEPA bubbler and a LESA sprayer to apply 7-day and 14-day irrigation interval strategies. This study so far has revealed the superiority of the combination of either a LESA sprayer or MDI-1 gal/h irrigation with 14-day irrigation intervals in achieving the highest cotton yield in the region.

The effects of full irrigation and two levels of water stress on tree physiology were investigated in a French prune orchard. The control treatment received approximately 100% of the estimated seasonal crop water requirements throughout the season. The moderate and severe water stress treatments were managed to decline from a fully watered status in late spring to a midday stem water potential of -1.5 and -2.0 MPa, respectively, by harvest. Water stress caused a clear reduction in stem water potential throughout the daylight period, as well as reductions in leaf conductance and photosynthesis, and all of these reductions were more severe with increasing water stress. In a moderate and severe stress treatment, the photosynthetic rate of fully exposed leaves was reduced to 90% and 81% respectively, of the control treatment. There was a linear decline in light saturated photosynthesis with a decline in stem water potential. However, the stress treatments also influenced leaf orientation and the resulting incident light distribution on leaves within the canopy, such that light was more uniformly distributed in canopies under water deprivation than it was under full irrigation. The overall effect of water stress was that the moderate and severe stress treatments had 101% and 93% respectively of calculated canopy photosynthesis compared with the control. This may account for the observed tolerance of prune production to deficit irrigation. A midday depression in assimilation was observed on most days in all treatments, but was not associated with feedback inhibition resulting from carbohydrate accumulation in leaves.

Rising temperatures and increasing water scarcity, which are already important issues, are expected to intensify in the near future due to global warming. Optimizing irrigation in agriculture is a challenge. Understanding the response of crop development stages to water deficit stress provides an opportunity for optimizing irrigation. Here we studied the response of two barley varieties (Rihane, Martin), to water deficit stress at three development stages (tillering, stem elongation, and heading) by measuring water status and grain yield components in a field experiment in Tunisia. The three stages were selected due to their importance in crop growth and grain development. Water deficit stress was initiated by withholding water for 21 days at the three stages with subsequent re-watering. Water deficit led to a progressive decrease in leaf water potential. In both varieties, heading was the stage most sensitive to water deficit. Leaf water potential measurements indicated that water ...

Introduction

Rice is one of the most important cereals in providing food security and the main food of billions of people in the Asian continent and many other parts of the world. Drought is the most important factor limiting rice production in paddy fields, which affects all stages of rice growth and development. Researches has shown that avoiding the conventional flood irrigation methods in rice cultivation and using alternative methods such as intermittent irrigation have a great effect on increasing water productivity and reducing its consumption. But in determining the most suitable alternative method of irrigation in each region, it should be noted that the effects of water shortage change with changes in the intensity, duration and time of its application. Today many Crop Growth Models (CGM's) have been designed to avoid the huge costs of conducting field research, speed up finding suitable solutions, and help to better understand and solve problems related to water movement in the soil and plant growth. Studies show that CGM's are able to consider the effect of different stresses such as water stress on dry matter production and grain yield during the growth period. One of the CGM’s is the AquaCrop model developed by FAO. The presence of factors such as moderate to severe water stress causes a significant decrease in the simulation accuracy by model, which is mentioned as one of the defects of the model. Most of studies with AquaCrop model have been limited to data collected in short periods. Therefore, the aim of this research is to evaluate the efficiency and accuracy of the AquaCrop model in simulating rice grain yield and biomass under multiple water stresses and during different years.



Materials and Methods

In order to evaluate the accuracy of the model in predicting the grain yield and biomass of rice, data collected from several research projects carried out in different years, the model was first calibrated and validated. The Hashemi variety used in all these projects, which is the most common variety cultivated in Guilan province. All agricultural operations of planting, growing and harvesting were carried out according to regional customs and the amounts of chemical fertilizers, herbicides and pesticides based on the recommendations of experts in agriculture and herbal medicine of the rice research institute. For the present study, a total of 45 irrigation treatments were selected from the previous projects carried out in the lands of the Country Rice Research Institute, Lahijan and Soumesara, of which 31 treatments were used for the calibration section and 14 treatments were used for model validation. The model was implemented for each irrigation treatment separately and the grain yield and biomass values obtained from the simulation were analyzed with the measured values based on the statistical indicators used in this research.



Results and Discussion

Based on the results of calibration of the model, the range of observed grain yield was 2100 to 4870 with an average of 3765 kg.ha-1. This is while the corresponding values simulated in the calibration conditions by the model were equal to 1749 to 4704 with an average of 3748 kg.ha-1. The accuracy of the model is low at the low limit of performance, but very accurate at the high and average performance limits. This phenomenon can be attributed to the estimation error of the model in the presence of environmental stresses such as water and fertilizer stress, which has also been mentioned in the studies of other researchers. Also, the values of RMSE and NRMSE for yield simulation were equal to 309.65 kg.ha-1 and 8.22%, respectively, which indicates very good accuracy in model calibration. Also, RMSE and NRMSE values for biomass simulation in calibration conditions were equal to 596.31 kg.ha-1 and 6.41%, respectively. The values of RMSE and NRMSE for the simulation of performance in the validation conditions were equal to 168.42 kg.ha-1 and 10.30%, which indicates good accuracy in model validation. Also, the values of RMSE and NRMSE for the simulation of biomass were equal to 554.71 kg.ha-1 and 12.90%, which shows the good accuracy of the model in validation. Examining the results of the model in different water stresses showed that with the increase of water stress from permanent waterlogging to high stress with the addition of irrigation cycles, the amount of model error in yield simulation increases.



Conclusion

In general, the AquaCrop model has good accuracy in simulating the grain yield and biomass of Hashemi variety rice, but the more severe the amount of water stress, the accuracy of the model decreases and its error increases. This problem is attributed to the structure of the model and the mathematical equations used in it, as well as the measured data. However, the AquaCrop model has many advantages such as the need for less data, the ability to be used for a wide range of crops and the user-friendliness of the model and it is recommended to use the AquaCrop model in different irrigation managements, especially in conditions without severe water stress, where the model has very good accuracy. But it is recommended due to the advantages of the AquaCrop model, such as the need for less data, the ability to be used for a wide range of crops and the user-friendliness of the model, its use in different irrigation managements, especially in conditions without extreme water stress, where the model has very good accuracy.

Introduction

Determining the appropriate amount of water for potato cultivation has been investigated by various researchers around the world and based on various factors such as irrigation methods, available technology, local climate and other management factors, various amounts have been presented. Based on these studies, the optimal amount of irrigation water for each region should be determined by field experiments. But doing it requires spending a lot of time and money. On the other hand, Iran's facing drought conditions in the coming decades and the need to optimize water consumption in the agricultural sector increases the importance of determining the optimal amount of irrigation water for potato production. To solve this problem and increase the speed of decision-making, plant models have been developed. The WOFOST model is one of the plant models introduced by Wageningen University in the Netherlands to simulate the growth and yield of agricultural plants. Although the WOFOST model has been widely used by researchers to simulate agricultural plants; But its use for potatoes has been less interesting to researchers. On the other hand, the optimal amount of potato irrigation water has been suggested by researchers around the world in a wide range, and it is necessary to determine and optimize these amounts in each region. Based on this importance, the present research was conducted to determine the optimal limits of potato irrigation water with the aim of achieving optimal yield and high water productivity. WOFOST model was used to simulate different irrigation scenarios.



Materials and Methods

This research was conducted in two crop years in a research farm located in Kermanshah city in the form of complete random blocks. The investigated treatments included the supply of irrigation water at the levels of 100 (T1), 75 (T2) and 50 (T3) percent of the potato plant's water requirement in T-Tape drip irrigation system. Irrigation treatments were the same until the 5-leaf stage, and after that, irrigation treatments were applied. In order to determine the amount of irrigation water in each treatment, volumetric meters were used. The amount of readily available water and soil residue (W2) and the percentage of usable water discharge or Re in the plant root zone were calculated using equations (1) and (2).

(1)



(2)



The WOFOST model is a plant growth simulation model based on the carbon cycle and has a complex structure. This model simulates plant growth in three conditions of no limiting factor, water limitation and food limitation. In fact, in the WOFOST model, crop growth is simulated based on eco-physiological processes. Before recalibration and validation of the WOFOST model, sensitivity analysis was performed based on equation (3):

(3)



In this regard, Sc is the dimensionless sensitivity coefficient, Pm is the estimated value of the desired parameter based on adjusted input data, and Pb is the estimated value of the desired parameter based on the basic input data. After the sensitivity analysis, the WOFOST model was recalibrated using the data of the first year and validated using the data of the second year of cultivation.



Results and Discussion

The statistical results of observed and simulated yield and water productivity by WOFOST model are shown in Table (1). According to these results, in the calibration phase, the WOFOST model had an underestimation error. The accuracy of this model based on the NRMSE statistic was in the excellent category. The error rate of WOFOST model for determining yield and water productivity was equal to 1.6 tons per hectare and 0.17 kg/m3, respectively. Based on two statistics, EF and d, the efficiency of this model to determine crop yield was better than water productivity.



Table 1- Statistical results of observed and simulated yield and water productivity by the WOFOST model in the calibration stage

MBE RMSE NRMSE EF D Unit Parameter

0.5- 1.6 0.06 0.93 0.99 Tons/ha Yield

0.06- 0.17 0.04 0.04- 0.99 kg/m3 Water productivity



The statistical results of yield and water productivity in the validation stage are shown in table (2). Based on the MBE statistic, the WOFOST model had an overestimation error in the performance simulation and an underestimation error in the water productivity simulation. Based on the NRMSE statistic, the accuracy of this model was excellent for determining both parameters. As in the calibration phase, the efficiency of the WOFOST model was better in simulating performance than water productivity.



Table 2- Statistical results of observed and simulated yield and water productivity by the WOFOST model in the validation stage

MBE RMSE NRMSE EF D Unit Parameter

0.1 0.93 0.03 0.97 0.99 Tons/ha Yield

0.04- 0.14 0.03 0.40- 0.99 kg/m3 Water productivity



In general, to determine the optimal scenario, it should be kept in mind that the difference between potato yield in two irrigation depths of 634 and 487 mm was greater than other depths, while the difference between water productivity between these two depths was only 5%. Therefore, the irrigation water depth of 634 mm is chosen as the optimal depth for irrigation. These results are close to the values suggested by Doornbos and Kassam (1979) in FAO publication No.33.



Conclusion

The results showed that the WOFOST model had the necessary accuracy (NRMSE<0.1) and efficiency (d>0.99) to simulate the yield and water productivity of potato in Kermanshah region. Based on these results, different irrigation water management scenarios were investigated on the yield and water productivity of this crop. The difference between potato yield in two irrigation depths of 634 and 487 mm was greater than other irrigation intervals. For this reason, the yield and water productivity values were compared with each other in this interval. Based on all the results, the depth of 634 mm was determined as the optimal value for potato cultivation. Potato yield at this depth is about 25 tons per hectare and water productivity is about 2.4 kg/m3. These values decreased and increased by 7.3 tons per hectare and 0.8 kg/m3 compared to providing 100% of the plant's water needs (975 mm of irrigation water).

Introduction
Rice (Oryza sativa L.) is one of the most popular cereals in the world and is known as the second most consumed grain in Iran after wheat. For this reason, it is essential to pay attention to the quantity and quality of this agricultural crop. The cultivation of ratoon rice, which has become common in some areas in the north of Iran, will enable the re-production of rice in the next cropping season. The lack of water resources in recent years in Iran and the prediction of the severity of the shortage of available water in the coming years have caused the use of methods to reduce water consumption in the agricultural sector, which is the largest water consumer in the country, to be considered Rice plant has a large share in water consumption per unit area among other agricultural products. For this reason, some methods of reducing water consumption in the cultivation of this product have been suggested. According to the existing restrictions on the use of irrigation water and nitrogen fertilizer, it is necessary to determine the optimal amounts of these factors in the field. However, this work requires many field experiments, which require a lot of time and money. To solve this problem, the use of simulation and optimization models has been suggested. Therefore, this research aims to optimize the two factors of irrigation water and nitrogen fertilizer to achieve the most appropriate amount of production and improve the quality of rice using the response surface methodology (RSM).

Materials and Methods
Considering the effects of two aforementioned factors, in this research the optimization of the amount of irrigation water and nitrogen fertilizer on the quantitative and qualitative characteristics of ratoon rice was applied using the response surface method. The study site was the research farm of the Rice Research Institute located at latitude 37º 16’ N and longitude 49º 63’ E in Rasht, Iran. The studied factors included the amount of irrigation water (with upper and lower levels of 0 and 5 mm of cracks appearing in the soil, respectively) and nitrogen fertilizer (with upper and lower levels of 90 and zero kg ha-1 of pure nitrogen, respectively). the RSM refers to a multivariate function. To compare the obtained model results with observed values, from the Root Mean Square Error (RMSE), Normalized Root Mean Square Error (NRMSE), Mean Bias Error (MBE), Efficiency Factor (EF), agreement index (d), and the Coefficient of Determination (R2) was used.

Results and Discussion
The results showed that the regression model for predicting the plant height, biomass, gel consistency, and yield had an underestimation error (MBE < 0), and for other parameters had an an overestimation error (MBE<0). The value of the NRMSE was less than 0.1, so the quadratic regression model had excellent accuracy for all parameters. The two statistics EF and d, which show the efficiency of the regression model, had acceptable values (d>0.90 and EF>0). After optimization, the yield of seed and biomass was 10.5% and 0.5%, respectively, higher than the average values of these parameters in field conditions. In optimal conditions, the number of tillers, panicle length, and harvest index were 1.9%, 1.4%, and 3.6% higher than the observed values, respectively, and plant height and weight of 1000 seeds were almost equal in both optimal and observational conditions. The changes in the quality indicators of gelatinization temperature, gel consistency, amylase content percentage, and grain elongation in optimal conditions compared to the observed values were 1.8 (less), 0.4 (more), zero, and 6.2 (more) percent, respectively. The amount of irrigation water and nitrogen fertilizer in optimal conditions was 3.5 mm of cracking in the soil and 68 kg ha-1, respectively.

Conclusion
In this research, the effect of two factors, irrigation water and nitrogen fertilizer, was optimized using the response surface method. For this purpose, the minimum and maximum values of these factors were considered with codes of -1 and +1. The results showed that, except for yield and biomass, other traits did not have uniform and regular changes with the increase of two factors, irrigation water and nitrogen fertilizer. For this reason, the overlap map of these factors was determined and it was observed that the effect of nitrogen fertilizer on most parameters was greater than that of irrigation water. The optimal range of all factors was in the values of -0.3 to +0.5 nitrogen fertilizer -1 to +1 irrigation water +0.5 to +1 nitrogen fertilizer and -1 to +0.7 irrigation water. Of course, a part of the overlapping area of these two ranges also lacked the optimal value for the parameters, which was considered by the surface-response method in the optimization. After optimization, it was observed that the two parameters of gelatinization degree and gel consistency were lower than the average observed values. The parameters of amylase percentage, 1000 seed weight, and plant height did not change compared to the field conditions and the value of other parameters increased. To achieve these results, it is necessary to consider the amount of irrigation water in cracks of 3.5 mm and the amount of nitrogen fertilizer as 68 kg ha-1.

Nowadays determining the optimum crop water requirements is considered one of the most important factors affecting plant productions, especially, with scarce water resources. This may be due to the interrelation between the amount of water added and the ability of plant. Two field experiments were carried out during the two growing seasons 2010/2011-2011/2012, at the Research Farm of the National Research Centre in Nubarya region, Egypt, to study the effect of both deficit irrigation and laser land leveling on saving water and increasing yield of wheat crop under Egyptian growing conditions. Studied factors were deficit irrigation (100% Irrigation Requirements "IR", 80%IR, 60%IR and 40%IR) and land leveling techniques (conventional "C" and laser "L"). The following parameters were studied to evaluate the effect of deficit irrigation and laser land leveling; (1) Soil moisture distribution, (2) Growth of wheat plant, (3) Yield of wheat , (4) Irrigation water use efficiency of wheat and (5) Economical parameters of wheat production process. Statistical analysis of the effect of the interaction between land leveling and irrigation on IWUE of wheat indicated that the maximum values were detected at adding 100%IR*L. However, no significant difference was observed between 100%IR*L >80%IR*L >and 60% IR*L, this means that we can save 40% of irrigation water by adding 60% IR with laser land leveling technique to irrigate wheat under sandy soil conditions.

Heavy metals can bioaccumulate and biotransfer from both natural and artificial sources. Given that heavy metal concentrations above normal seriously threaten both plant and animal life, their contamination of plants and water is one of the biggest problems facing the globe today that must be addressed. In this work, we attempt to evaluate the buildup of heavy metals in the soil, their penetration into plants, and their impact on the physiological and biochemical functions of olive trees. Therefore, it was interesting to research the concentrations of heavy metals in Sidi Khaled-Derna plants and soil. Soil samples' physical and chemical properties, including pH, electrical conductivity, organic matter mass, phosphorus and nitrogen content. Random soil samples were taken from the study areas, the first area as the control (Barborg) and the second as the polluted area (Sidi Khaled). The results showed that the concentrations of metals in the soil exposed to the pollution and the trees growing in it were greater than those found in the unpolluted area and were higher than the safe recommended values. While the electrical conductivity of the same sample was above the standard range set by the World Health Organization, the pH of the polluted soil was below the normal limit. In addition, the amount of phosphorus, nitrogen, and organic matter were lower than in control. Notable decline in the activity of the studied antioxidant enzymes in trees growing in the polluted area, and all of the results indicated that the stressed olive trees had higher levels of phenolic compounds and the amino acid proline, which are believed to be markers of oxidative stress in plant cells, compared to control trees.

The response of phenolic composition of skins from Vitis vinifera L. ‘Tempranillo’ and ‘Graciano’ grapes to water-deficit irrigation during berry growth and ripening was evaluated. The study was carried out using container-grown grapevines grown under controlled conditions in a greenhouse. Two irrigation treatments were imposed: control (well-watered) and sustained deficit irrigation (SDI). Twenty-eight phenolic compounds, including anthocyanins, flavonols and monomeric flavan-3-ols (catechins) as well as phenolic acids derivatives have been identified in the extracts prepared from the berry skins at physiological maturity. For both varieties, water deficit reduced leaf area and leaf area to crop mass ratio, and decreased berry size. However, there were no changes in juice total soluble solids, pH or total polyphenolic content. Water deficit resulted in decreased must titratable acidity in ‘Graciano’ berries. In ‘Tempranillo’, water limitation reduced total anthocyanins and flavonol...

Introduction
The water shortage in the agricultural sector in recent years and its continuation in the future is an undeniable reality in Iran. Super absorbent materials can be used to cope with the effects of drought and water stress on plants. As a result of absorbing and storing water, these materials can change the amount or frequency of irrigation water. To ensure the optimal development of the root structure of medicinal plants, aerial parts, and essential oil percentage, it is necessary to create optimal conditions for providing moisture. It is time-consuming and costly to conduct multiple tests to achieve this objective. Thus, simulation and optimization models have been suggested to solve this problem. The researcher must first prepare the required data for each combination of treatments mentioned in this model, then build a statistical model based on it. The next step is to determine the optimal conditions for the independent variables so that the dependent variables approach their maximum, minimum, or target value. According to the literature review, response-surface methodology (RSM) has been effective in determining the optimal values of factors in the agricultural sector. As a result, it can be also used to optimize the application of super absorbent in peppermint cultivation. So, this study was designed to optimize the use of super absorbent in different irrigation rounds to maximize quantitative and qualitative traits of peppermint (Mentha piperita).

Materials and Methods
The present research was conducted in the research greenhouse of the Agricultural Engineering Research Institute (AERI) in Karaj in 2018-2019. Specifically, three irrigation intervals (two, four, and six days) and three weight percent of Aquasource superabsorbent (zero, one, and two %W of superabsorbent/soil) were tested. Before irrigation, the moisture content in each pot was measured using a Lutron Professional Soil Moisture Meter (PMS-714), and the amount of irrigation in each round was determined based on the amount of moisture deficiency up to the field capacity (FC). The central square design is one type of response surface method. In this method, independent variables are determined to determine the predicted dependent variable through an experimental design. This design considers the average levels of the factors as the central point. Using this method, the experimental treatments are displayed as +1, zero, and ‒1, which represent the highest, average, and lowest levels of the independent variable, respectively. Using regression analysis of variance, linear terms, quadratic terms, and interactions between factors were added to the multivariate regression model to evaluate the model-data fit. Finally, the significance of the model and its accuracy in fitting the data were determined. To compare the obtained model results with observed values, the root mean square error (RMSE), normalized root mean square error (NRMSE), mean bias error (MBE), efficiency factor (EF), agreement index (d), and the coefficient of determination (R2), were used.

Results and Discussion
Variance analysis showed that the regression model for water productivity was statistically significant at the five percent probability level (P-value≤0.05) and for the other traits studied at the one percent probability level (P-value≤0.01). In contrast, quadratic regression was statistically significant only for root weight, root length, shoot weight, essential oil percentage, and water productivity traits. The regression of other traits was not statistically significant. Therefore, the RSM cannot be used to predict and optimize these traits. Based on the lack of significance of the lack of fit test, the results of regression analysis are reliable compared to variance analysis. The RSM was also confirmed to be effective in optimizing the traits studied. The overlapping map of the investigated parameters was prepared to determine the optimal limit and common surface. In the upper range of this map, which includes the most irrigation intervals and super absorbent consumption; parameters such as water productivity do not change much. This parameter reaches its maximum value in the center of the map. Generally, other parameters tend to reach the optimal limit within the range of the bottom right part of the map, so, to optimize the parameters of root weight, root length, shoot weight, essential oil percentage, and water productivity, their target values were determined as 1.1 kg m-2, 3 cm, 2 kg m-2, 3 %, and 4 kg m-3.

Conclusion
The effects of different irrigation intervals (three levels of two, four, and six days) and Aquasource super absorbent (three levels of zero, one, and two %W of super absorbent/soil) were examined on some peppermint plant traits. Results showed that the response-surface model did not significantly differ from statistical methods. As a result, it is possible to trust the results obtained. The traits of root weight and length, shoot weight, essential oil percentage, and water productivity were used in the RSM, and all other traits were found to increase with an increase in irrigation water, except for essential oil percentage and water productivity. In terms of essential oil percentage and water productivity, the reduction in irrigation intervals to +0.8 levels had an upward trend and then it declined afterward. Increasing the amount of super absorbent negatively affected the characteristics of root weight and length, shoot weight, and essential oil percentage. As the amount of super absorbent was increased to a range of -0.3, water productivity increased, and then the value of this parameter also decreased. As a result of these conditions, the RSM was effectively used to optimize the irrigation interval and super absorbent amount, and it was determined that the best conditions were obtained by utilizing a three-day irrigation interval with a super absorbent concentration of 0.3%. Therefore, compliance with these conditions is recommended for peppermint cultivation.

The impacts of regulated deficit irrigation (RDI) and partial root zone drying irrigation (PRD) on water productivity (WP), crop water response factor (Ky), and yield of tomato crop (Solanum lycopersicum) were explored in this study using fresh (0.9 dS m−1) and saline (3.6 dS m−1) water under greenhouse conditions. RDI had four ETc (crop evapotranspiration) levels, i.e., 40, 60, 80, and 100%. PRD adopted 100% ETc for all treatments with changes in its application time (first, second, third, and fourth growth stages). Biochar pyrolyzed at 450–500 °C and added at rate of 4%. The results revealed that the Ky ranged between 0.21 and 0.37, indicating that tomato can tolerate a shortage of irrigation water. The highest value of WP (191 kg m−3) was found in 40% ETc using fresh water with biochar. The highest yield (20.0 kg m−2) was obtained with the application of 100% ETc with fresh water and biochar. Biochar application did not result in favorable yields with saline water due to its high...

The use of saline water under drought conditions is critical for sustainable agricultural development in arid regions. Biochar used as a soil amendment to enhance soil properties such as water-holding capacity and the source of nutrition elements of plants. Therefore, the experiment was conducted to evaluate the effects of biochar application on the morpho-physiological traits and yield of tomatoes under combined salinity and drought stress into greenhouses. There were 16 treatments consist two water quality fresh and saline (0.9 and 2.3 dS m-1), three deficit irrigation levels (DI) 80, 60, and 40% addition 100% of ETc, and biochar application by rate 5% (BC5%) (w/w) and untreated soil (BC0%). The results indicated that the salinity and water deficit negatively affected morphological, physiological, and yield traits. In contrast, the application of biochar improved all traits. The interaction between biochar and saline water leads to decreased vegetative growth indices, leaf gas exc...

The effects of the crop density and nitrogen rates on the ear length, number of kernel rows and the 1000-kernel weight were observed in this study. The four-replicate tow-year experiment was set up according to the completely randomized block design on the chernozem type of soil that had been intensively fertilized intensively by organic and mineral fertilisers for many years. The study encompassed the four nitrogen rates (90-240 kg ha-1) and four crop densities (49,300-75,200 plants ha-1). The obtained results show that the 1000-kernel weight, as well as, the ear length, mostly declined by the increase of both crop density and nitrogen rates (up to a certain level). The increasing crop densities and applied nitrogen rates did not affect the number of kernel rows.Istraživan je uticaj gustine useva i količine azota na dužinu klipa, broj redova i apsolutnu masu zrna kukuruza. Ogled je izveden na černozemu dugo godina intenzivno đubrenim organskim i mineralnim đubrivima po blok sistemu...

Erratic rainfall, within and between years, leads to high uncertainty in runoff reservoir operations in many Sub-Sahara African (SSA) countries. Severe food shortages attributed to drought affect millions of vulnerable households, particularly those whose livelihoods depend on agriculture. We construct and successfully simulate a stochastic dynamic model of a small runoff reservoir fashioned after the Tono Reservoir in Northern Ghana. Our model considers a reservoir authority who at the beginning of each season observes the stock of water in the reservoir and, in the wet season, the amount of rainfall, and must decide how much water to release from the reservoir for irrigation and how much acreage to irrigate in order to maximize returns to the agriculture over the three growing seasons. We drive optimal irrigation policies with and without access to emergency groundwater pump irrigation systems and with and without access to rainfall index insurance. The optimal irrigation policies...

Soil samples from the various treatment plots were analysed before and after 60 days of planting to determine the amount of nitrogen, phosphorus and potassium (N, P, and K). Similarly, moisture contents were determined before planting, at the developmental and mid stage of growth. It was observed that treatment two which was the 80% application of ETc performed better than the others. It was also observed that the 60% application of ET C gave the poorest results. It can be concluded that irrigating with 80% of estimated water requirement, is the best application for okro.

Over the last years modeling plant transpiration has been pointed out as a powerful tool to optimize the management of irrigation in fruit trees. In this study we tested the hydromechanical model of stomata functioning proposed by , a model with a strong physiological basis. The great contribution of this model is that its parameters have direct physiological meaning. Firstly, the model was simplified to make its parameters estimation friendly and easy. Secondly, the model was fitted to data obtained in a hedgerow olive orchard under regulated deficit irrigation. The hydromechanical model fitted our data satisfactorily and allowed us to analyze the physiological parameters obtained.

This paper presents data from sixteen collecting missions conducted over three decades (2000-2023) in the Lubelskie Voivodeship, located in Southeastern Poland. During these missions, 756 samples of functional plants were collected, along with accompanying species such as weeds, crop wild relatives, ornamental plants, spice plants, and grafts of fruit trees. These materials were compared with those collected during six expeditions in two earlier decades (1980-1999), which resulted in the collection of 665 genotypes. The samples were primarily obtained from local farmers or gathered directly from fields. This study aims to summarise and compare the results of the collecting missions across decades. The analysis indicates that the Lubelskie region remains a place where old varieties of annual vegetable plants, rare weed species (on a national scale), crop wild relatives, and old varieties of fruit trees can still be found. However, old cereal varieties have nearly disappeared. The collected materials were characterised and stored as a base collection under long

Introduction
The agriculture sector, as the biggest consumer of water to produce more food, has faced the challenge of water shortage. One of the problems ahead in the agricultural industry is the sustainable use of available resources such as land, water, and labor to increase agricultural production and development, which requires proper planning and management policies. Plant models can be used to investigate the long-term effects of quantitative and qualitative changes in irrigation water on crops, soil salinity, evaporation and transpiration, deep infiltration, and surface runoff. One of the widely used plant models is the AquaCrop model, which was presented and developed by the World Food and Agriculture Organization. The Aquacrop model is one of the crop yield estimation models that can be used for a wide range of crops including fodder crops, vegetables, grains, fruits, oil crops, and tubers. In this model, the state of various stresses including water and soil salinity, simulation of lack of irrigation, and crop yield are considered. Various studies have been conducted regarding the calibration and validation of crop forecasting models in our country, and much research has been conducted on wheat at the global level. In this research, the AquaCrop model was used to predict the biomass and grain yield of wheat in Qazvin. This model can be a good substitute for field measurements and can be used in areas where there is a lack of ground information.

Materials and Methods
In the present research, the data of water wheat cultivation in a lysimeter in Ismailabad, Qazvin were used. The input information of the AquaCrop model includes information on climate, soil, management, and plant characteristics. To calibrate and verify the model, some farm information was needed to be compared with the output of the AquaCrop model. The biomass of the wheat plant was determined by taking random samples of the 0.5×0.5 m2 with two replications per sampling hectare. To measure grain yield in the fields, four samples were taken at the end of the growing season at the end stage. The validated AquaCrop model was used to estimate the effect of three planting dates and three low irrigation conditions on wheat grain yield. In this step, the average regional information around the farms was used so that the implementation of the model is not unique to the conditions of a particular farm.

Results and Discussion
In terms of the investigated meteorological factors, the model has moderate sensitivity to maximum and minimum temperature and low sensitivity to rainfall. The change in the maximum temperature in this region increases the error of the simulation on average. Regarding the soil parameters, the sensitivity of the model to the crop capacity moisture, wilting point, saturated moisture, and saturated hydraulic conductivity, especially in saturated conditions, is low to medium. The most sensitive of the AquaCrop model was the change in the reference harvest index. The model simulated biomass values with higher accuracy than yield. In the calibration stage, the values CRM, NRMSE, and d for biomass were -0.15, 0.17, and 92% respectively. These values were obtained in the validation stage for biomass -0.1, 0.24, and 92 % respectively, and for yield -0.03, 0.06, and 80 % respectively. By running the model in different climatic scenarios, it was determined that the maximum delay in the planting date is on November 15. A 25% reduction in irrigation water reduced grain yield in wet, normal, and dry years by 15%, 20%, and 28 %, respectively, and a 50 % reduction in irrigation water reduced its amount by 20, 25, and 45 %, respectively.

Conclusion
Evaluation of the AquaCrop model for common plants in a region plays an important role in comparing crop performance in different conditions. In this research, the ability of AquaCrop 6 model to estimate the yield and biomass of wheat in Ismailabad Qazvin was investigated. The results showed that the model is capable of simulating these factors with high accuracy. The accuracy of the model in biomass simulation was higher than the grain yield. By implementing the calibrated model in different climatic scenarios, planting dates, and irrigation deficits in two regions, it was determined that to achieve optimal performance, the wheat planting date should not exceed 15 November. It was the use of calibration coefficients by spending a long time in the AquaCrop model so that a calibrated model can be used in many areas with proper accuracy. More accuracy in the simulated results can be achieved by using more calibration factors, but it is clear that the use of more calibration factors requires spending more time and money. Finding a general recalibrated model that can be used in large areas is a good solution in crop management at the farm-to-regional scale. Comparing the statistical parameters obtained in this study with previous studies on wheat yield modeling by the AquaCrop model shows that the results of this study are within an acceptable range.

Introduction
Today, water security is one of the important limitations of development, especially in dry and desert areas. Because these areas not only have low rainfall, but also this low rainfall is not properly distributed. Despite the increase in irrigation efficiency in some agricultural methods, the limitation of freshwater resources in some areas makes it necessary to use salt water in agriculture. However, the use of these water sources has negative effects on the soil and the environment. So the salinity of soil and irrigation water reduces crop yield and puts soil resources at serious risk. It is possible to increase the crop yield and control soil erosion by using the appropriate irrigation method. The problem of salinity in plants is due to the accumulation of excessive amounts of sodium chloride, which is widely spread in coastal areas, soils of dry areas, and fertile lands. Studies have shown that the use of saline water, especially in conditions of equal fertilization between treatments, often reduces the absorption of important nutrients such as nitrogen due to the existence of a significant relationship between the absorption of water and nutrients. Research in the north of Golestan province showed that salinity causes a significant decrease in plant biomass. The effect of salinity stress on the accumulation of sodium, potassium, and chlorine in the plant was significant and the highest amount of ions was accumulated in the leaves. The plant's root system is selective in absorbing and transferring sodium to its aerial parts.

Materials and Methods
To do this research, first, by selecting 36 experimental units, holes with a diameter of 50 cm and a depth of 60 cm were dug in the center of each one, and then the treatments were prepared. This research is in the form of treatments consisting of irrigation factor (clay and drip irrigation method), salinity level (salinity up to 1200, salinity up to 2200, and salinity up to 3200 µmhos cm-2), and plant (Rose and Hibiscus sabdariffa) in three repetitions and it was done factorial randomized complete blocks design. Three water sources each with a capacity of 200 liters were placed at a height of less than two meters from the ground. Rose plant was prepared in the form of potted seedlings and Hibiscus sabdariffa seeds were planted in the greenhouse and after about two weeks in March, it was transferred to the field. The growth height of the plants, as well as the crown, the diameter of the plant stem, and the number of their branches in the growing season were measured. Also, three soil samples were collected and their characteristics of salinity, acidity, and texture were measured. In order to analyze the data, the statistical method of analysis of variance (ANOVA) and the least significant difference (LSD) test were used to compare the average of the studied indicators using MSTAT-C software and SPSS software.

Results and Discussion
The results of variance analysis of some growth traits of the studied species showed that seedling height and stem diameter were affected by different levels of salinity and the values ​​of this plant characteristic showed a statistically significant difference. The reason for the decrease in plant growth in a plant that is irrigated with more salinity is that the presence of salt in the soil exceeds the tolerance threshold of the plant, and as a result, the accumulation of excess salt in the root zone is a limiting factor for plant growth. According to the results of the effect of irrigation methods, as well as the interaction effect of salinity and irrigation method on the aforementioned indicators, there was no statistically significant difference. The interaction effect of plant and water salinity levels on the values ​​of these variables was significant. The comparison of the average data showed that the height of the studied species was significantly increased by using the clay irrigation method. The maximum diameter of the stem was also measured in the clay irrigation method, which was associated with an increase of 1.7\% compared to the drip irrigation method. Also, the results show that the highest values ​​of the studied variables are related to the rose flower plant, which is 1.7 and 3 times more than the sour tea plant, respectively. Clay irrigation causes water to be transferred to the root area of ​​the plant, which improves the performance and growth of the plant by providing the required moisture around the root. In other words, the way to distribution soil moisture in clay irrigation takes place in the form of percolation and uniformly around the root of the plant, which causes the moisture to be placed directly around the root area and thus affects the growth of the plant. In addition, the canopy data and the number of branches showed that there is no significant difference between them.

Conclusion
This research tested the effect of different levels of water salinity and clay and drip irrigation on the establishment of plants in the Sistan plain, considering the existence of a water shortage crisis in the region, in order to use saline water on two plants, rose and Hibiscus sabdariffa. The results showed that clay irrigation performance was better than drip irrigation at all salinity levels. Because in the drip irrigation method, with the occurrence of drought stress, it reduces plant growth compared to the clay irrigation method. In addition, in the drip irrigation method, water is placed on the soil surface and deep penetration is limited, and as a result, the increase in humidity in the subsurface layers is less. In the clay irrigation method, due to deep penetration and uniform distribution of moisture in the soil profile, the amount of moisture stored in the soil increases.

It is incumbent to assess the status of U.S. rice production and its agronomic practices and then predict if the status is sustainable with climate change. Climate change expectations include a strong likelihood of higher temperatures and some uncertainty in precipitation. Technological solutions appear to be revolving around (i) rice breeding to improve cultivar heat tolerance, especially for high nighttime temperatures, and (ii) altering irrigation regimes to conserve groundwater. Of concern are the potential of protracted droughts in the Sacramento Valley of California, salinization along the gulf coast and aquifer depletion across portions of the mid-South. The objectives of this manuscript include: (i) evaluate existing US Mid-South rice irrigation strategies, (ii) assess the yield potential and seed quality of emerging water-conserving irrigation regimes, (iii) assess the influence of rice irrigation regimes on aquifer overdraft, and (iv) assess the influence of increased temperatures on rice growth and development. Alternate wetting and drying irrigation and furrow irrigation are attractive irrigation regimes to reduce aquifer depletion. Yield trials show mixed results, with yield differences associated with soil type, timing and frequency of irrigations, nitrogen fertilization, and variety selection. Producer acceptance of furrow irrigation is rapidly developing, even in rice producing regions that have not experienced aquifer overdraft.

Aims: A field study was conducted to quantify the effect of moisture deficit stress at different critical stages of quinoa and different mitigation approaches were adopted in order to alleviate moisture deficit stress. Study Design: The experiment was designed in split plot design comprising of six main plots (water management) and four sub plots (stress mitigation approaches). The treatments in main plots viz., no irrigation at branching (M1), at ear formation (M2), flowering (M3), grain filling (M4) stages, irrigating at all four stages (M5) and irrigating as and when required (M6), and sub plot treatments viz., soil test-based fertilizer recommendation (STBFR) (S1), STBFR + Salicylic acid spray at 100 ppm (S2), STBFR + rice straw mulching (S3) and integrated nutrient management (S4) were tested. Place and Duration of Study: The experiment was conducted at the Instructional Farm, Odisha University of Agriculture and Technology, Bhubaneswar during Rabi 2021-22. Methodology: Moistur...

Aims: A field study was conducted to quantify the effect of moisture deficit stress at different critical stages of quinoa and different mitigation approaches were adopted in order to alleviate moisture deficit stress. Study Design: The experiment was designed in split plot design comprising of six main plots (water management) and four sub plots (stress mitigation approaches). The treatments in main plots viz., no irrigation at branching (M1), at ear formation (M2), flowering (M3), grain filling (M4) stages, irrigating at all four stages (M5) and irrigating as and when required (M6), and sub plot treatments viz., soil test-based fertilizer recommendation (STBFR) (S1), STBFR + Salicylic acid spray at 100 ppm (S2), STBFR + rice straw mulching (S3) and integrated nutrient management (S4) were tested. Place and Duration of Study: The experiment was conducted at the Instructional Farm, Odisha University of Agriculture and Technology, Bhubaneswar during Rabi 2021-22. Methodology: Moistur...

Water scarcity poses a growing threat to agricultural productivity in arid and semi-arid regions like Central Ethiopia. This study evaluated the role of deficit irrigation (DI) and furrow irrigation systems in enhancing water use efficiency (WUE) and maintaining garlic (Allium sativum L.) yield under limited water conditions. A field experiment was conducted in the Tiyo District, comparing four irrigation levels (100%, 85%, 70%, and 55% of crop evapotranspiration, ETc) across three furrow irrigation systems: conventional (CFI), alternate (AFI), and fixed (FFI). The study followed a randomized complete block design with 12 treatments replicated three times. Results revealed that the highest yield (9862.4 kg/ha) was achieved under CFI100%ETc, while the highest irrigation water use efficiency (28.64 kg/mm) was recorded under AFI100%ETc. Moderate deficit irrigation (85% and 70% ETc) under AFI significantly improved both crop water productivity and water savings without a statistically significant yield loss. These findings demonstrate that AFI combined with moderate DI can optimize water use and sustain garlic production in water-scarce areas. The study provides evidence-based recommendations for improving irrigation practices to enhance agricultural productivity and resilience in regions experiencing water stress.

Water is a biggest gift and blessing for agriculture practices. Real-time irrigation monitoring was crucial in crop understanding and evaluation. Currently every region global wise suffering from water scarcity and shortage due to abrupt climate change behaviour. The Utilisation of precision farming practices includes water saving technology for efficient water management system under such condition will put-forth better solution for farming communities. Through precision irrigation system, the delivery efficiency for crop plants gets maximize, thus promoting better water uptake, plant growth and lied on sustainability in water usage. Through reducing the water usage can aids for future generation farming. Thus, the present study article highlights the key use of potential precision irrigation system in agriculture.

Criteria based on economics are essential to rationalize water use from the highest investment payback perspective in irrigated agricultural systems decision support. The central goal of this work is to provide theoretical basis for calculating the optimal time of water supply in freedrainage furrow irrigation systems. The purposed methodology might be generalized to different situations, being basically explained by: a) yield function (total applied water versus yield); b) duration of each phenological stages followed by their corresponding crop coefficients; c) parameters regarding to advance and infiltration equations; and d) information related to price of marketable products, costs of water and the other production factors. The specific values of parameters and attributes should be provided or suggested from users. The outputs to be achieved should denote a time of water supply regarding to maximum mean net income, which is obtained from different scenarios of water deficits that are corresponding to different fractions of required water to be infiltrated at the end of the furrow.

Erratic and inadequate rainfall is one of the important factors for crop production under rain fed conditions. Crop grown as sole crop are found to be rather risky due to delayed monsoon accompanied with prolonged intermittent dry spells. A strategy for stabilizing production of dry-land crops through commonly recognized practice of intercropping of compatible crops is considered viable to overcome the situation. Mothbean and pearlmillet are important arid crop. So it is necessary to find out its intercropping proportion to resuce the risk of failure of sole crop. Therefore, an experiment was conducted at Dry

The present study was carried out at Water Management Research Centre, University of Agriculture, Faisalabad, Pakistan, to investigate the effect of row spacing, deficit irrigation and dual plantation on tomato yield grown in high tunnel under polyethylene black mulch and drip irrigation system. The field experiment layout comprised of three rows spacing (S1, S2 and S3) as (0.45, 0.60, and 0.75 m respectively) and two irrigation levels (I1 and I2) as (100% and 75% of required irrigation respectively). In addition, a dual plantation treatment spaced at 0.45 m was also investigated under both irrigation levels. Results showed that the total fruit yield was significantly influenced by row spacing and irrigation level, however, their interaction was non-significant. The 100% irrigation gave 6.53, 4.49, and 5.94% more yield than 75% irrigation treatment under 0.45, 0.60, and 0.75 m row spacing, respectively. However, the irrigation water use efficiency was found to be higher in deficit t...

In a field study, crop responses were investigated under three treatments; firstly irrigation system (bed-furrow irrigation and drip irrigation systems), secondly water quality (good, marginal and poor quality waters), and thirdly irrigation frequency/interval (2, 4 and 6 days). The experiment was laid out in a completely randomized design arrangement with three replications of all levels of different treatments in the experiment. Field observations suggest that plant height, dry matter weight, grain yield and harvest index were all quadratically related with irrigation frequency. The variables performed better in 2 and 6 day frequency plots compared with those of 4-day plots. Good quality water upgraded plant dry matter weight by 11.7%. The main effect of irrigation quality on plant dry matter weight was observed statistically significant. Similarly grain yield were 7.5, 6.38 and 5.33t/ha respectively for good, marginal and poor quality water. The main effect of irrigation water quality tested highly significant for grain yields. Crop parameters registered better performance for bed-furrow irrigated plots compared with drip irrigated ones in respect of plant height (1.0%), dry matter weight (5.8%) and corn yield (21.9%). It is conclude that good quality irrigation water produces better crop yield under 2 and 6day irrigation frequency, followed by 4-day irrigation frequency.

As an important medicinal plant used in traditional and modern medicine, chili peppers are sensitive or moderately sensitive to drought or salt stress, respectively. Therefore, potential changes due to foliar-applied glutathione (GSH; 0, 0.4 and 0.8 mM) response on growth, yield, and physio-biochemical attributes, as well as water use efficiency (WUE) and fruit alkaloid capsaicin of chili pepper plants were investigated when grown under deficit irrigation in salt-affected soil (EC = 6.74 dS m–1). Two deficit irrigation water (DiW) regimes (80% and 60% of soil field capacity; FC) were used versus 100% of FC as a control. Both DiW treatments negatively affected growth and yield parameters, SPAD chlorophyll index, nutrient status, K+/Na+ ratio, and plant anatomical features. In contrast, osmoprotectants, ascorbate, glutathione, capsaicin, and phenolic contents, as well as WUE were increased in association with higher Na+ and Cl– contents. However, exogenously-applied GSH caused signifi...

Net shading was explored as a corrective tool for mitigating the effect of a single year drought event on apple ('Imperial Gala') yield in Bologna (Italy). In 2013, trees were grown under three nets with different shading levels (red-50%, white-50%, and black-20%) and without nets. Those treatments received three irrigation doses from 60 days after full bloom until harvest: 260 (control), 115 (moderate water stress, WS) and 50 (severe WS) Shade netting mm of water. Control trees had midday stem water potential (Ψ stem) values around -1.0 MPa when they were shaded, but values were more negative when they were grown without nets. Ψ stem ranged between -1.0 and -1.5 MPa under moderate WS and was about -1.5 MPa for severe WS although this value was reached sooner in trees grown without nets. Leaf photosynthesis decreased with more negative Ψstem values but was not affected by shading. Yield was very low (3-4 kg per tree) for trees grown without nets with no differences between irrigation treatments. Yield was also very low for shaded trees grown under severe WS (5-7 kg per tree). Under control and moderate WS, shaded trees had higher yields (9-13 kg per tree) than trees grown without nets, but no differences were found between shading. The benefits of net shading on yield were explained by several additive factors: i) improved water status, ii) delay in fruit maturity giving more time to the fruit to grow, and iii) reduction of photo-inhibition. These results may encourage fruit growers to install nets in their orchards when water is limited. Under severe water stress conditions net shading was not effective and low yields are expected. No effect of net colour was observed but its effect may be observed in a longer term. Further research is necessary to determine the sustainability of shading over multiple years.

The present work analyzes the effects of different water application levels on agronomic parameters and water use efficiency of a durum wheat (Triticum durum Desf. Var. Karim.) cultivar under the Mediterranean climatic conditions in central Tunisia. The objective of this work was to identify an appropriate irrigation strategy associated with high crop water use efficiency. Field experiment was conducted at the Higher Institute of Agronomy of Chott Meriem during the growing season 2011-2012. The irrigation strategy consisted in maintaining fixed the irrigation intervals and changing the volumes of water applied as a percentage of the crop water requirements. The effects of three irrigation treatments were investigated. The irrigation treatments were full irrigation (T1) corresponding to 100% of predetermined irrigation water levels, (T2) 75% of full irrigation and (T3) 50% of full irrigation. Results concerning water use efficiency revealed that T1 and T3, with respectively 1.72 and 1.6 kg/m 3 , were classified in the same group. T2, with 1.43 kg/m 3 , resulted in lowest water use efficiency. Comparing the effects of water supply on yield components, the best results were registered for T1 while the lowest yield components were obtained for T3. LAI from T1 was significantly higher than in the other treatments. According to the study results, each increase in irrigation regime increased days to maturity. The results achieved in this study showed that irrigating winter wheat with continuously providing only 50% of the crop water requirements in semi arid climate in Tunisia could result in high efficient irrigation water use.

We appreciate Tihomir Ancev's interest in our research on the economic consequences of multiyear droughts (Peck and Adams 2010). Ancev raises two concerns about our paper in their comment. First, he is concerned that our main conclusion (i.e. drought in one year can influence the effects of drought in subsequent years) may be an artefact of our representation of crop interdependencies as 'agronomic rules.' He asks, specifically, whether our conclusion would change if we allowed the model to make trade-offs between drought management and pest and disease management. Ancev's second concern is that our conclusion does not hold for all drought scenarios we analysed. Because our conclusion does not hold universally (across all states of nature in the analysis), Ancev questions its validity. He closes by recommending an alternative approach that would compare the effects of single versus multiyear drought events. Ancev is correct that agricultural producers facing drought are not rigidly bound by agronomic rules, but instead face trade-offs between crops that help manage scarce water resources and those that help manage pests and diseases. Producers may violate agronomic rules if they are more concerned about mitigating the financial impact of drought in the current year than the financial impact of increased pests and diseases in future years. Continuous production functions would capture the yield effects of alternative crop sequences more precisely and allow marginal trade-offs between drought and pest/disease management. Unfortunately, we found no such production functions in the literature for our study area's major crops (wheat, corn, sugar beets and onions). estimated production functions for wheat and corn in the Pacific Northwest, but their study did not include beets or onions, so their production functions do not capture the yield effects of sugar beets or onions on wheat and corn, or vice versa. Nor were adequate production data available from the study area to estimate functions that capture crop interdependencies.

Agricultural producers throughout much of the United States experienced one of the most severe droughts in the last 100 years during the years 1999-2006. The prolonged nature of this drought highlights a need to better understand the impacts and management of drought across growing seasons, rather than just within a growing season. Producers express specific concern about the tendency of drought impacts to persist even after drought itself has subsided. The persistence of drought impacts has received limited attention in the economics literature. The objectives of this study are two-fold: 1) to determine whether inter-year dynamics, in the form of agronomic constraints and financial flows, can cause persistence of a drought's impact in years subsequent to the drought, and 2) to determine whether the impact of one year of drought can alter the impact of a subsequent year of drought. A multi-year, dynamic and stochastic decision model is developed in a discrete stochastic programming framework and solved to address the objectives. The structure and parameters of the farmlevel model are based on irrigated row crop farms in eastern Oregon, USA. Analysis of the model's solution reveals the following results: 1) the impact of a drought can persist long after the drought subsides, and 2) the impact of one year of drought can alter the impact of a subsequent year of drought. Potential implications for the administration of drought-related assistance are discussed briefly.

Climate change will affect water resources through its impact on the quantity, variability, timing, form, and intensity of precipitation. This paper provides an overview of the projected physical and economic effects of climate change on water resources in North America (with a focus on water shortages), and a brief discussion of potential means to mitigate adverse consequences. More detailed information on this complex topic may be found in Adams and Peck (forthcoming) and in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4).

A conservação dos escassos recursos hídricos na região Nordeste do Brasil exige um programa de gerenciamento mais eiciente. A má distribuição pluvial na localidade, a urbanização e as secas periódicas intensiicam a demanda por água. Entretanto, a ocupação urbana ainda modiica a morfologia espacial sem se atentar para o potencial paisagístico natural, enquanto busca reproduzir padrões estéticos externos e distintos. Diante disso, faz-se necessária a percepção da urgência de minimizar o desperdício de água. Remodelar a paisagem através de planejamento e modiicações adequadas não só ajudam a reduzir seu consumo, mas também os custos com sua manutenção. Nesse sentido, o presente trabalho apresenta soluções paisagísticas mais eicientes em termos de economia hídrica e combate à desertiicação na região semiárida brasileira. Técnicas como ordenamento da lora por necessidade de água, elaboração de oásis artiiciais, utilização de mantas e quebra-ventos demonstram eiciência quando aliados aos mecanismos de sobrevivência inerentes à vegetação nativa.

This experiment aimed to assess the impact of de cit irrigation on both the quantitative and qualitative yield of forage maize hybrids. The study was structured as a split-plot design, utilizing a randomized complete block design with three replications, where took place at the Agricultural Research Station of Gorgan in the years 2021 and 2022. De cit irrigation was implemented at four different levels as the main plots, which comprised 100%, 75%, 50%, and 25% of the water requirement. These main plots were further subdivided into subplots, consisting of four hybrid varieties, namely SC703, SC704, ZP548, and BK50. The results showed that the highest total biomass (47939 kg ha - 1 ) was obtained under 100% water requirement (control) and SC704 hybrid. The reduction in total biomass for the treatments at 75%, 50%, and 25% of the water requirement, when compared to the control treatment, amounted to 7%, 47.4%, and 79.1%, respectively. De cit irrigation signi cantly affected qualitative traits except for NDF at the level of 1% and increased all quality traits. Accordingly, the highest percentage of CP, NDF, and ADF was obtained by hybrid SC703 with 50% water requirement (by 9.20%), hybrid BK50 under 25% water requirement (by 30.73%), and BK50 with 75% water requirement (by 44.03%). The highest water use e ciency was observed in 75% of the water requirement (7.79 kg m - 3 ). Considering the signi cant reduction in water consumption (1795 m 3 ha - 1 ) achieved with this treatment, it is advisable to recommend irrigation at 75% of the water requirement alongside the cultivation of the SC703 hybrid for forage production in the northern region of Iran.

Raising quality hybrid potato true seedlings -derived from hybrid true potato seeds (TPS) -for field transplanting is a critical aspect contributing to the success in cultivating field-transplanted hybrid potato seedling-based crops. Various critical seedling vigour attributes must be defined and enhanced to improve plant performance as well as plant response and adaptation to field conditions after field transplanting. Moreover, additional attributes besides leaf number and stem length should be defined to design selection criteria for "transplantability" of potato seedlings. To assess these attributes and their robustness under different environmental conditions, seedlings of hybrid genotypes were raised under contrasting daylengths, light intensities and temperature regimes, and combinations of these factors, and the effects of these factors (or factor combinations) on seedling vigour and its attributes were quantified. Increased light intensity and daylight integral (DLI) enhanced leaf parameters and increased biomass under long-day conditions, but seedlings did not show conclusive responses under short-day conditions in most attributes. Higher temperatures increased biomass and constant day and night temperatures enhanced compaction of shoot architecture as did higher light intensities -to a greater extent. These results highlight additional seedling vigour attributes including leaf area parameters and seedling biomass which should be utilised to determine "transplantability" of hybrid potato seedlings. Additionally, the results provide a starting point for further research on optimising hybrid seedling production for field transplanting.

Perspective HIGHLIGHTS  Declining enrollments in a declining number of university degree programs in irrigation engineering are generating concern about the future of irrigation engineering expertise.  Technical degree and certificate programs offer options for professionals in irrigation careers, especially those in landscape irrigation careers requiring licensure.  Extension programs are evolving to include more on-demand internet-based and social media-based information delivery, as audiences have become more accustomed to these platforms.  Addressing workforce and expertise needs in irrigation engineering is critically important, and it will involve equipping future professionals to address national and international challenges in agriculture. ABSTRACT. Irrigation continues to be economically important in the U.S. and internationally, yet there is concern about future accessibility to appropriate expertise and the engineering preparation of irrigation professionals for both public and private sectors. Recent and impending retirements of academic and industry leaders, losses of some important academic programs (curricula/degree programs, research, and extension) in irrigation engineering, and reduced numbers of students threaten to significantly limit irrigation engineering capacity, especially in agricultural irrigation. Some of the challenges can be met through opportunities afforded by development of distance education programs; expansion of multi-state, multiagency, multi-university collaborations; and increasing public-private partnerships, as well as through vigorous recruitment efforts. Recruitment can be strengthened by improving the competitiveness of salaries to be commensurate with other engineering disciplines, and by demonstrating and better explaining the abilities of the irrigation engineering profession to meet future challenges related to food, fiber, fuel, and ecosystem demands of a rapidly growing global population. While access to irrigation engineering expertise, especially domestic expertise, has declined, the need for such technical support and information for practitioners has not decreased. In fact, in many cases, technical advancements from public and industry developments have greatly outpaced the capacity for applied research and extension programs to robustly evaluate technologies and deliver objective, science-based recommendations. Growing knowledge gaps and time lags have exacerbated restlessness among some audiences, increasing the opportunities for promotion of unsubstantiated claims for some products that remain unchallenged, and further confusing appropriate selection from a growing array of available technologies.

Several factors, including multi-year drought, declining aquifer levels, and new water regulations, are contributing to reduced availability of irrigation water in the semi-arid area of west-central Nebraska. Since many farmers in this area do not have enough water to meet the seasonal water requirements of crops like corn and soybean, maximizing yield produced per unit of water under deficit irrigation conditions is becoming increasingly important. This study was conducted to quantify the grain yield response of soybean [Glycine max (L.) Merr.] to deficit irrigation, and to determine which seasonal water variables correlated best to soybean grain yield under deficit irrigation. The study was conducted during 2002 at Curtis, and at North Platte, Nebraska. Nine deficit irrigation treatments, including different irrigation amounts and timings, were studied in 2002 and 2003, and eight treatments were studied in 2004. Soybean grain yields across years and sites were best related to the seasonal ratio of the actual crop evapotranspiration and the crop evapotranspiration when soil water was not limiting (ET d /ET w ), and to the seasonal ratio of actual crop transpiration and crop transpiration when soil water was not limiting (T d /T w ). Both of these seasonal ratios were linearly related to grain yield with R 2 = 0.91 when combining data for all seasons. The crop water productivity (CWP) (yield per unit of seasonal ET d ) linearly increased with both ET d /ET w (R 2 = 0.72) and T d /T w (R 2 = 0.72), but was best correlated to the daily positive difference between the actual and the theoretical fraction of total available soil water in the root zone that can be depleted before crop water stress occurred, accumulated for the entire season (seasonal p diff ) (R 2 = 0.77). A linear relationship between the cumulative ET w and fraction of season (function of days after emergence) was found. This relationship developed for a given location could be used to extrapolate seasonal ET w for in-season irrigation management. Poor correlation was found between CWP and other variables such as total irrigation, rain + irrigation, and total water. The results of this study can provide useful information for soybean irrigators to make better management decisions under deficit irrigation conditions.

Irrigation water use efficiency is an important issue for both agricultural production and optimization of water resources in arid and semi-arid regions where water resources are limited. Surface drip irrigation (DI) is used in most of these areas. However, subsurface drip irrigation (SDI) has become widespread in recent years. Therefore, the effects of SDI method on the plant and contributions on the water saving should be examined and compared with the DI method in different plant and climate conditions. The aim of this study was to compare the effects of surface drip (DI) and subsurface drip irrigation (SDI) methods on canopy temperature measured with infrared thermometer and to evaluate deficit irrigation effects on soybean grown at the Batı Akdeniz Agricultural Research Institute (BAARI), Antalya, Turkey in 2017. The study was designed in a randomized complete block design to include two irrigation methods (surface drip (DI) and subsurface drip irrigation (SDI)) and four different irrigation treatments (0%, 60%, 80%, and 100%) in three replications. The canopy temperatures were measured by an infrared thermometer between 12:00 and 15:00 hours before and after irrigation. Conclusions: The results showed that the canopy temperatures of the plants irrigated with the SDI method throughout the season were up to 2.5°C lower than the DI method. Also, the yield values obtained from the SDI method (439.1 kg da -1 ) were statistically higher than DI method (395.2 kg da -1 ). When compared to the DI method, a water saving of approximately 78.3 mm was obtained in SDI method. Significance and Impact of the Study: It was determined that the canopy temperatures of soybean irrigated with SDI method were lower compared to the DI method. In addition, there was a high level of exponential relationship and negative correlation between canopy temperatures and yield, applied irrigation water and evapotranspiration in both irrigation methods.

Nowadays, water scarcity is a great danger to agriculture development, in semiarid and arid regions beside climate change risks. Egypt is suffering from scarce water resources for agriculture; it is of high priority to rationalize irrigation water use. During two seasons, 2019/2020 and 2020/2021 the experimental were carried out to investigate the effect of three different irrigation water treatments (I 1 at 45, I 2 at 60 and I 3 at 75% depletion of available soil moisture) on some photosynthetic, agronomical, grain quality parameters, water productivity for eight barley genotypes. Also, classify them on the SSR molecular level. The results showed that there were high genetic variations found among the eight genotypes with significant responses to irrigation water treatments. Rationalize irrigation water from I 1 to I 3 had a negative effect on all studied phenotypic traits, whereas had an appositive effect on leaf diffusive resistance and cured protein content and inducement all genotypes to flower early by average increasing (27.7, 12.7 and 7.08%) respectively. Giza 138,

During the 2017/2018 and 2018/2019 seasons, a study was conducted on the effect of humic acid at 1.0, 1.5, and 2.0 ml L-1 and water productivity on essential oils and proline content, biotic stress caused by Cucumber Mosaic Virus (CMV) and yield of geranium plants. The study was conducted in El Kanater El Khairia of Qalubia Governorate. It was aimed at determining the appropriate concentration of humic acid that attains the highest water productivity (WP), the highest production of essential oils, and highest proline content as well as reducing the symptoms of CMV. Results indicate that the highest fresh yield was obtained with a foliar application of 2.0 ml L-1 humic acid and 120% evapotranspiration (ETo). Applied irrigation water was 15155, 12168, and 9334 m3 ha-1 in the first growing season and 15218, 12298, and 9678 m3 ha-1 in the second growing season with 120, 100, and 80% ETo in both seasons. The highest average of WP 9.31 kg ha-1 both seasons was attained with 80% ETo and, 2...

Increasing population and food demand, disproportionate cultivation and annual production of various agricultural products with market needs and low productivity of the agricultural sector and the loss of water and soil resources have made it necessary to determine and implement the country's optimal cropping pattern. In this study, due to the limitations and problems of classical methods in order to reduce processing time and improve the quality of solutions, the Multi-Objective Chaotic Particle Swarm Optimization was used to determine the optimal cultivation pattern of Sistan plain in optimal conditions and deficit irrigation. The results of the Multi-Objective Chaotic Particle Swarm Optimization for the dominant cultures in the region showed that the current cropping pattern of the region is not optimal and with the implementation of the proposed model, the profit per unit area under cultivation will increase. The results of application of deficit irrigation during different growing periods of wheat, barley, alfalfa, sorghum, watermelon and grapes showed that applying deficit irrigation in this plain is not a good strategy and therefore only a full irrigation strategy is recommended. The results of sensitivity analysis of the model showed that at low prices, farmers reaction is less and at higher prices more reaction to price changes and with increasing prices, the program efficiency is lower.

Evapotranspiration as an important component of the hydrological cycle plays a very important role in the planning and management of water resources in dry and hyper dry areas. Accurate estimation of evapotranspiration requires a costly tool which can not be used anywhere. Hence, researchers are always looking for applied relationships and practices that are low-cost and accurate for the correct estimation of the value of this parameter. Several methods have been developed for the accurate estimation of evapotranspiration throughout the world. Among of these methods can be pointed out empirical equations, Artificial Neural Network, support vector machin, and tree models. Therefore, the purpose of this study was to investigate the accuracy and the capability of linear supporting vector machine models, the decision tree of the type of chiad and the random forest model in the estimation of reference evapotranspiration.The data used in this study include maximum temperature, minimum temperature, average temperature, maximum moisture content, minimum humidity, average humidity, precipitation, sunny hours, wind speed, and a shift from the meteorological station of Sistan Plain between2009-2018. In this study, using meteorological data and the FAO Penman-Monteith model, the values of evapotranspiration were calculated and then by providing different combination scenarios of the meteorological parameters as inputs of the studied models on a daily basis, an attempt was made to find a more accurate estimate of the refrence evapotranspiration as the output of the models. In this research, correlation coefficient (R) and Mean Absolute amount of Error (MAE) were used to compare different model. The results showed among the support model carriers, the random knife, the random forest model with M7 patterns has the highest accuracy with the correlation coefficient (R = 0.983) and the lowest mean error magnitude (MAE = 0.798). Therefore, this research recommends a random forest model for estimating evapotranspiration in the area of Sistan plain.