Sprinkler Irrigation

Although solutions of multidimensional transient water flow can be obtained by numerical modeling, their application may be limited as root water uptake is generally considered to be one‐ or two‐dimensional only. This is especially the case for trees. The first objective of this paper is to test the suitability of a three‐dimensional root water uptake model for the simultaneous simulation of transient soil water flow around an almond tree. The soil hydraulic and root water uptake parameters were optimized by minimizing the residuals between measured and simulated water content data. Water content was measured in a three‐dimensional grid around a sprinkler‐irrigated almond tree for a 16 day period, following irrigation. A second objective was to compare the performance and results of the three‐dimensional flow model with one‐ and two‐ dimensional root water uptake models. For this purpose, measured water contents were aggregated in the x and y direction in the one‐dimensional case an...

Although solutions of multidimensional transient water flow can be obtained by numerical modeling, their application may be limited in part as root water uptake is generally considered to be one‐dimensional only. The objective of this study was to develop and test a two‐dimensional root water uptake model, which can be incorporated into numerical multidimensional flow models. The two‐dimensional uptake model is based on the model by Raats, but is extended with a radial component. Subsequently, the root water uptake model was incorporated into a two‐dimensional flow model, and root water uptake parameters were optimized, minimizing the residuals between measured and simulated water content data. Water content was measured around a sprinkler‐irrigated almond tree (Prunus laurocerasus M.J.Roem) for a 16‐d period at 25 locations, following irrigation. To calibrate the flow and root water uptake model, a genetic algorithm (GA) was used to find the approximate global minimum of the optimi...

Introduction
Delivery discharge to each outlet, the number of outlets grouped in a block, and the sequence of water delivery to the outlets are the three main components of water delivery in irrigation networks. Therefore, scheduling the distribution and delivery of water in the network means a determination of these three components. In this research, an optimal water delivery model was developed. The proposed approach was applied to the M canal of the Moghan Irrigation Network of Iran. By choosing a certain number of blocks, the outlets located in the distribution canal are distributed inside each block in such a way that all the outlets are placed inside the blocks and no block is left without outlets. In the following, the way of scheduling water delivery to each of the outlets located in each block and the flow rate delivered to them is such that the flow rate of the canal, the time required to complete the irrigation scheduling, and also the difference in the volume of water delivered to each outlet are minimized. The limitations of the model are: a) the total flow entering the outlets that collect water at the same time should not exceed the capacity of the canal. b) the total water intake time of the outlets inside each block should not exceed the irrigation interval. In this research, the allocation of water and the cultivated area in the optimal water allocation model, which is linked to the crop model, were used to optimize water delivery.

Materials and Methods
Delivery discharge to each outlet, the number of outlets grouped in a block, and the sequence of water delivery to the outlets are the three main components of water delivery in irrigation networks. Therefore, scheduling the distribution and delivery of water in the network means the determination of these three components. In this research, an optimal water delivery model was developed. The proposed approach was applied to the Canal M of the Moghan Irrigation Network of Iran. By choosing a certain number of blocks, the outlets located in the distribution canal are distributed inside each block in such a way that all the outlets are placed inside the blocks and no block is left without outlets. In the following, the way of scheduling water delivery to each of the outlets located in each block and the flow rate delivered to them is such that the flow rate of the canal, the time required to complete the irrigation scheduling,g and also the difference in the volume of water delivered to each outlet are minimized. The limitations of the model are: a) the total flow entering the outlets that collect water at the same time should not exceed the capacity of the canal. b) the total water intake time of the outlets inside each block should not exceed the irrigation interval. In this research, the allocation of water and the cultivated area in the optimal water allocation model, which is linked to the crop model, were used to optimize water delivery.

Results and Discussion
By using the volume of water allocated to each crop and cultivated area, the water demand for each outlet in different time steps was obtained. Following determining the water demand of each outlet and also by knowing the physical characteristics of the canal, optimal water delivery modeling was done in the canal for each time step by using the optimal water delivery model and genetic algorithm. Water delivery factors are presented for the 17th time step (peak demand period). The results show that the optimal flow does not exceed the minimum and maximum flow of each off-take. Also, the shorter total duration of the exploitation process than the irrigation interval indicates compliance with the relevant condition in the model. The hydrograph of the inflow into Canal M showed that the maximum flow of the inflow into the canal is less than the capacity of the canal, which indicates compliance with the relevant condition in the model. The hydrograph of the inflow to the canal provides the number of settings of the main off-take of the distribution canal. During the completion of the water delivery program, the main off-take of the distribution canal, which receives water from the main Canal A, is adjusted a total of 23 times by the network operator.

Conclusion
In this research, the optimization model of water distribution and delivery in distribution canals was developed using a genetic algorithm in MATLAB software. With the aim of optimal allocation and delivery of water at different levels of the irrigation network and by combining the crop model, the results and output of the models were combined with each other so that the results of optimal water scheduling are more appropriate with the real conditions and water requirements of the network. For the canal in the peak demand period, the maximum and minimum canal capacity were calculated to be 2.573 and 0.590 m3.s-1, respectively, the maximum time to complete the irrigation program was 232 h, and the number of settings of the main off-take was calculated as 23 settings. The obtained results indicate that the developed models are useful for scheduling the optimal allocation and delivery of water and with its help different goals can be optimized simultaneously.

In the short water supply environment of Pakistan, farmers try to minimize the gap between demand and supply of canal water extracting groundwater for irrigation purposes. However, saline groundwater upconing may occur in response to fresh groundwater withdrawals from unconfined aquifer underlain by salty groundwater. Skimming well technology can help in controlling this upconing phenomenon. However, in most cases, the small discharges of such wells cannot be efficiently applied on surface irrigated croplands. Pressurized irrigation application systems use small discharge effectively, but the cost and availability of equipment in the local market is a significant constraint. Root zone salinity is also expected to increase if this skimmed groundwater is used for irrigation purposes, particularly in the absence of proper salinity management practices.

Factor H is introduced for direct head loss calculation and sizing in dual-diameter laterals of sprinkler and trickle irrigation systems when the Hazen-Williams equation is to be applied. Application of this factor prevents trial and error and uses fewer head-loss equations in calculating the total friction loss and designing dual-diameter laterals. The proposed factor is a function of total number of outlets on the lateral, number of outlets on the smaller-diameter section of the pipe and ratio of smaller diameter to the larger diameter pipe. By solving two practical examples, the advantage of this factor over other approaches was shown. It was also demonstrated that design of lateral sizing by the given equations is simpler, easier and more accurate than the previous methods.

Scarce water resources frequently limit crop production in semi-arid lands. Drip irrigation may constitute a method for sagacious management of water resources, but there is still limited information on its use for sugar beet crop in Mediterranean environments. The present study was conducted to determine the effect of irrigation on sucrose accumulation and root yield, as well as on sugar beet physiological responses, and to compare drip and low-pressure sprinkler (high efficiency) irrigation performances for sugar quality. As the main scope of the study was to give indications to allow water saving, the comparison focused on the best irrigation method when a similar amount of water was applied. Sugar beets were grown in an experimental field site in southern Italy (Molise Region) for two consecutive growing seasons (1999/2000 and 2000/2001). The water applied ranged from 50, 75, and 100% of the estimated evapotranspiration (ET); unirrigated sugar beets were taken as control plants. In both years, harvest was completed in two periods. Increasing volume of water replaced was advantageous for crop performances, and yield and physiological responses of sugar beets drip irrigated with 75% of estimated ET matched in most cases those of low-pressure sprinkler irrigated with 100% of estimated ET, resulting in potential 25% of water volume saving. In general, drip irrigation influenced positively many of the considered physiological and technological parameters, as compared to low-pressure sprinkler irrigation. Differences in root production and sugar quality between the two harvest periods were not significant. Results indicate that (1) increasing the amount of water applied gives benefits in terms of sugar beet root yield and sucrose accumulation, (2) drip irrigation (even applied every-other-furrow) appears to be consistently advantageous with respect to low-pressure sprinkler irrigation for sugar beet performances in semi-arid environments, (3) there are indications that suggest sugar beet growers should harvest in advance (of traditional harvest dates).

In the short water supply environment of Pakistan, farmers try to minimize the gap between demand and supply of canal water extracting groundwater for irrigation purposes. However, saline groundwater upconing may occur in response to fresh groundwater withdrawals from unconfined aquifer underlain by salty groundwater. Skimming well technology can help in controlling this upconing phenomenon. However, in most cases, the small discharges of such wells cannot be efficiently applied on surface irrigated croplands. Pressurized irrigation application systems use small discharge effectively, but the cost and availability of equipment in the local market is a significant constraint. Root zone salinity is also expected to increase if this skimmed groundwater is used for irrigation purposes, particularly in the absence of proper salinity management practices.

El riego por aspersión, al igual que los otros métodos de riego, se caracteriza por no aplicar la misma cantidad de agua en todos los puntos de la parcela regada, sino que siempre habrá algún grado de desuniformidad. Con el propósito de estudiar la uniformidad de aplicación del agua en superficie y en el suelo bajo un sistema de riego por aspersión estacionario, así como el efecto sobre el cultivo de caraota (Phaseolus vulgaris L.), se desarrolló una investigación durante los años 2008 y 2009 en el Campo Experimental de Riego del Decanato de Agronomía de la UCLA. Los resultados muestran que la uniformidad de los riegos acumulados medida sobre la cubierta vegetal (CUa) y en el perfil del suelo (CUs) fueron mayores que la uniformidad promedio de los eventos de riegos individuales, y que la uniformidad del rendimiento del cultivo de caraota tiene mayor aproximación al CUs después del riego. La variabilidad del rendimiento, de sus componentes y del índice de cosecha fue ligeramente mayor en el ciclo 2009 que en el 2008, y se debió a la mayor variabilidad de las láminas de riego acumuladas recibidas en cada subparcela de dicho ciclo.

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A remote sensing package called the agricultural irrigation imaging system ͑AgIIS͒ aboard a linear move irrigation system was developed to simultaneously monitor water status, nitrogen status, and canopy density at one-meter spatial resolution. The present study investigated the relationship between water status detected by AgIIS and soil moisture for the 1999 cotton ͑Gossypium hirsutum, Delta Pine 90b͒ season in Maricopa, Ariz. Water status was quantified by the water deficit index ͑WDI͒, an expansion of the crop water stress index where the influence of soil temperature is accounted for through a linear mixing model of soil and vegetation temperature. The WDI was best correlated to soil moisture through the FAO 56 water stress coefficient K s model; stability correction of aerodynamic resistance did not improve correlation. The AgIIS did provide field images of the WDI that might aid irrigation scheduling and increase water use efficiency.

The main purpose of this study was to compare two methods of surface and drip irrigations based on parametric evaluation system. This study was performed on a surface area of 3000 ha in Rimakan region in Behbahan city located in Khuzestan province of Iran. Properties of lands (slope, drainage, soil texture, and topography) and physical and chemical properties of soil (lime, salinity, alkalinity, calcium, and carbonate) were the basis for the parametric evaluation. Lands evaluation was performed after analysis using geographical information system (GIS). Results showed that 10% of the studied lands were appropriate for surface irrigation and 22.45% of the lands were appropriate for drip irrigation and the rest of the lands were inappropriate for both irrigation methods. Drip irrigation method in comparison with the surface irrigation can increase production capacity of lands, but it must be noticed that the main limiting parameters in determining irrigation method in one region are s...

SUMMARYThe line-source sprinkler irrigation system provides a continuously variable water application rate, which depends on distance from the line-source. The system is simple to set up and minimizes the amount of land required for experimental work. As the irrigation treatments are allocated systematically, the assumptions of analysis of variance are not satisfied. It is proposed that the effects of irrigation treatments be assessed using analysis of covariance, with distance from the sprinkler line as covariate, thus adjusting for a linear fertility trend. This method of analysis provides an approximate residual mean square for the fitting of response curves, but could be vulnerable to a quadratic fertility trend.

Articles on chemigation with fungicides targeting foliage have been reviewed. They included 23 fungicides tested on 10 crops. Many studies compared chemigation to a check treatment, while others also included conventional methods. Chlorothalonil, followed by mancozeb, fentin hydroxide and captafol were the most studied fungicides, while peanut (Arachis hypogaea), potato (Solanum tuberosum), tomato (Lycopersicon esculentum), and dry beans (Phaseolus vulgaris) were the most studied crops. Center pivot, followed by solid set, were the irrigation systems most frequently used. The minimum volume of water applied by some center pivots (25 000 litre ha-1) is 25 times the maximum volume of water used by conventional ground sprayers. The reduction of fungicide residue on foliage caused by the very large volume of water used by chemigation might be oþ set by the following factors : (1) fungicide application at the time of maximum leaf wetness when fungi are most active, (2) complete coverage of plants, (3) reducing greatly the inoculum on plant and soil surface, (4) better control of some soil pathogens, and (5) more uniform distribution of fungicides by center pivot. Furthermore, chemigation avoids mechanical damage and soil compaction. Additionally, some systemic fungicides seem to be absorbed rapidly by the leaves, by root uptake from the soil, or by both. In general, all fungicides applied through irrigation water can lessen disease severity. However, when compared to conventional methods, chemigation with fungicides can be less, equally or more eþ ective depending on crop, pathogen, disease severity, fungicide and volume of water. For Cercosporidium personatum control on peanuts, application of protectant fungicides through irrigation water is less eþ ective than conventional methods, but the results with some systemic fungicides mixed with nonemulsiüed oil and applied through a relatively low volume of water (2.5 mm) are encouraging. Important diseases of potato and tomato can be controlled nearly as well by chemigation as by conventional methods without impairing yield. The main advantage of chemigation for these crops is avoiding a large number of tractor trips through the üeld and reduced costs of fungicide application. Chemigation has also been shown to be a good option for control of white mold [ Sclerotinia sclerotiorum ] on dry beans.

2.1. Uraian Umum Dalam pekerjaan perencanaan suatu sistem jaringan irigasi tambak pasang surut diperlukan berbagai bidang ilmu pengetahuan yang saling mendukung demi kesempurnaan hasil dari perencanaan. Bidang ilmu pengetahuan itu antara lain ilmu irigasi, ilmu tentang pasang surut, rekayasa tambak, hidrologi, hidrolika, bangunan air, dan rekayasa lingkungan untuk menganalisis dampak lingkungan akibat pembangunan jaringan irigasi tersebut. Untuk menunjang proses perencanaan jaringan irigasi tambak pasang surut ini perlu adanya kajian pustaka untuk menentukan spesifikasi-spesifikasi yang akan menjadi acuan dalam perencanaan tersebut. Berbagai teori dan rumus-rumus dari berbagai studi pustaka sangat diperlukan, terutama untuk pengolahan data dan untuk membuat desain rencana.

Sustainability of water supply networks should be based on the risks of water hammer phenomenon. The purpose of this study is to provide a new approach to the analysis of water hammer phenomenon in the water supply network. By conventional methods, the damage because of water hammer is estimated based on the maximum pressure at nodes. However, during this phenomenon continuation and changing of water hammer in overtime is ignored. In this study, quantitative parameters, to evaluate the network performance will be assessed under the water hammer phenomenon. Hence, the information through the parameters of reliability, resilience, vulnerability and their composition, sustainability parameters are analyzed. However, numerical analysis of water hammer phenomenon caused by sudden pump stop was done using HAMMER software. The results showed that the sustainability parameter can be used to evaluate the efficiency of water networks. In the event of water hammer phenomenon 4.83 percent of po...

Polyacrylamide (PAM) for erosion control is an effective soil conservation practice used on about a million hectares worldwide. Initial research and promotion focused primarily on furrow irrigation erosion reduction and sediment retention. PAM use increases infiltration on fine-and medium-textured soils due to differences between non-treated and PAM-treated surface seals. However, subsurface compaction and coarse texture reduce the infiltration effects of PAM use. Infiltration increases with PAM in sprinkler irrigation are initially large, but more transient than with furrow irrigation. Understanding these effects has important implications for management.

The mechanics of soil erosion from irrigated and rainfed lands are similar. Soil particles are detached, transported and deposited. However, there are some systematic differences between irrigation and rainfall erosion. Electrolyte concentrations in irrigation water, for example, are almost always greater than in rain water. Differences between rainfall and irrigation are more prominent for surface irrigation than for sprinkler irrigation. For instance, rainfall wets the soil before runoff begins, but water initially flows onto dry soil in irrigation furrows. Furthermore, furrow flow rate decreases with distance and increases with time, while the opposite tends to occur with rainfall. For sprinkler systems, travel direction and slope aspect interact, so runoff can flow within the irrigated area or from the irrigated area onto dry or wet soil. Thus, a sprinkler-irrigation erosion model must consider both the rainfall-runoff situation and the furrow flow situation. These differences in soil and water interactions must be considered before computer models can accurately simulate irrigation-induced soil erosion.

Izvod: Na oglednom polju Instituta za povrtarstvo u Smederevskoj Palanci, postavljen je dvogodišnji ogled s ciljem ispitivanja uticaja organskih đubriva na prinos po biljci rotkve u čistom i združenom usevu s boranijom. Korišćeni su dobro zgoreli stajnjak (FM) i mikrobiološko đubrivo koje sadrži Bacillus megaterium, Bacillus licheniformis, Bacillus suptilis, Azotobacter chrocoocum, Azotobacter vinelandi i Derxia sp. Kontrolne tretmane su činile neđubrene parcele i parcele tretirane mineralnim đubrivom. Prosečan prinos po biljci rotkve za sve tretmane u obe godine istraživanja bio je 228,8 g. Najveći prosečan prinos po biljci (344,3 g), zabeležen je 2011. godine u združenom usevu kod tretmana mineralnim đubrivom a najmanji (178,2 g), zabeležen je 2010. godine u čistom usevu kod tretmana bez upotrebe đubriva. Ključne reči: organska đubriva, prinos po biljci, rotkva, združeni usev. Rotkva (Raphanus sativus var. major L.) je dvogodišnja, uslovno jednogodišnja biljna vrsta koja je korišćena još u antičko doba. Pripada familiji Brassicaceae. Poznato je da je na obradivim površinama prisutna u značajno manjoj meri u odnosu na kupus, karfiol i rotkvicu ali nema statističkih podataka o tačnim površinama na kojima se gaji (Anonimus, 2014). Zastupljena je pretežno u baštama i na okućnicama (Miladinović i sar. 1997). Na većim površinama uzgaja se kao postrni usev, posle pšenice ili ječma (Popović, 1989). Gaji se najčešće zbog zadebljalog korena koji se koristi za pripremanje salate posebne dijetetske vrednosti i karakterističnog mirisa i ukusa (Aleksić i Aleksić, 1995). U botaničkom smislu predstavlja zadebljali hipokotil tj. deo stabla ispod kotiledonih listića i deo korena. Može biti različitog oblika i boje . U zavisnosti od sorte i uslova uspevanja, prosečna masa korena se kreće između 30 g i nekoliko kilograma, kod nekih japanskih sorti (Lazić i sar. 1991, Jilani i sar. 2010, Jatoi i sar. 2011). Najrasprostranjenije sorte u našim uslovima, Zimska crna i Zimska bela, prosečnim prinosima po biljci ne premašuju 500 g (Aleksić i Aleksić, 1995).

Iran, has caused most of the water used and as much as possible to avoid losses. One of the important parameters in agriculture is water distribution uniformity coefficient (CU) in sprinkler irrigation. CU amount of water sprinkler operating depends on different pressure heads (P), riser height (RH), distance between sprinklers on lateral pipes (Sl) and the distance between lateral pipes (Sm). The best combination of the above parameters for maximum CU, is still unknown for applicators. In this research, CU quantities of zb model sprinkler (made in Iran) were measured at Hashemabad cotton research station of Gorgan under 3 different pressure heads (2.5, 3 and 3.5 atm), 2 riser heads (60 and 100 cm) and 7 sprinkler (Sl×Sm including 9×12, 9×15, 12×12, 15×12, 12×18, 15×15, 15×18m) arrangements. By using differential evolution algorithm (DE), CU equation was optimized and the best optimized coefficients obtained. In this algorithm, the coefficients F and CR equal to 2 and 0.5, respectively, with a population of 100 members and 1000 number of generations (iterations), provides the best results. Absolute error between the results of this algorithm with the measured results is 2.2%. As well as values Wilmot (d) and the rootmean square error (RMSE), equal to 0.919 and 2.126, respectively. This results show that this algorithm has high accuracy to estimate water distribution uniformity.

Iran, has caused most of the water used and as much as possible to avoid losses. One of the important parameters in agriculture is water distribution uniformity coefficient (CU) in sprinkler irrigation. CU amount of water sprinkler operating depends on different pressure heads (P), riser height (RH), distance between sprinklers on lateral pipes (Sl) and the distance between lateral pipes (Sm). The best combination of the above parameters for maximum CU, is still unknown for applicators. In this research, CU quantities of zb model sprinkler (made in Iran) were measured at Hashemabad cotton research station of Gorgan under 3 different pressure heads (2.5, 3 and 3.5 atm), 2 riser heads (60 and 100 cm) and 7 sprinkler (Sl×Sm including 9×12, 9×15, 12×12, 15×12, 12×18, 15×15, 15×18m) arrangements. By using differential evolution algorithm (DE), CU equation was optimized and the best optimized coefficients obtained. In this algorithm, the coefficients F and CR equal to 2 and 0.5, respectiv...

The SWAT (Soil and Water Assessment Tool) has been used to evaluate the impact of several best management practices (BMPs) on water yield (WYLD) and total phosphorus (TP) at the outlet of the Del Reguero stream watershed (Spain). In total, 6 individual scenarios and 14 combinations of various management practices including tillage (conservation and no-tillage), fertilizer (incorporated, recommended, and zero), and irrigation (adjusted to crop needs) were been tested. Results indicate that the best individual BMPs (adjusted irrigation water use BMP) reduced WYLD to 31.4% and TP loads to 12.8%, in comparison of the initial conditions. When individual BMPs were combined, the reductions of losses were increased. The BMPs combination between optimum irrigation application, conservation tillage and reduced P fertilizer dose was the best analyzed one with a TP loads reduction about 22.6%.

On-farm trials on rice crop were conducted at farmer field over a span of three years (2018, 2019 and 2020) to assess the effectiveness of micro-irrigation methods (specifically drip and sprinkler irrigation) on water usage and crop yield in rice cultivation. The aim was to compare these methods with the conventional surface irrigation (flooding) method both in transplanted (manually or mechanically) and direct seeded rice so as to determine the feasibility of micro-irrigation in rice to tackle the problem of groundwater depletion in Haryana. In transplanted rice (TPR), grain yield obtained with drip and sprinkler irrigation was statistically similar to that obtained with conventional method. But the yield of direct seeded rice (DSR) increased significantly (15.1- 21.1% increase) when it was irrigated by drip or sprinkler methods than by conventional method. The yield of DSR was significantly lower than that of TPR when it was irrigated by conventional surface flooding method but the DSR yielded at par with TPR when irrigated by drip or sprinkler method. The grain yield of the crop obtained with drip and sprinkler irrigation was at par, irrespective of the crop establishment techniques.  Over the conventional irrigation, the drip and sprinkler irrigation saved
54.4-57.2% and 47.4-49.0% of irrigation water, respectively in TPR whereas the saving of irrigation water over the conventional method in DSR was 52.5-53.9% and 38.3-39.3%, respectively. Irrespective of establishment techniques, the highest water use efficiency was achieved with drip irrigation (6.73-9.46 kg/ha/mm), followed by sprinkler irrigation (5.66-7.85 kg/ha/mm) whereas it was the lowest with the conventional irrigation (3.28-3.55 kg/ha/mm). It is evident from the findings that it is feasible to adopt sprinkler irrigation in rice (both in TPR and DSR) as it saved substantial quantity
of irrigation water without any penalty in yield and net profit in TPR and even increased the yield and net profit in DSR over the conventional irrigation method. Therefore, sprinkler irrigation can be an effective strategy to manage the depletion of groundwater in Haryana. On the other hand, the drip irrigation, despite saving more water and being comparable to the sprinkler irrigation in respect of its effect on yield, may not be economically viable due to its higher initial cost.

Nitrate leaching as a result of excessive application of N-fertilizers and water use is a major problem of vulnerable regions. The farming of maize requires high N fertilization and water inputs in Spain. Isotopic techniques may provide information on the processes involved in the N and C cycles in farmed areas. The aim of this work was studying the impact of sprinkler and furrow irrigation and N input on maize (Zea mays L.) yields, and whether isotopic composition can be used as indicator of best farming practices. Trials were set up in Tudela (Spain) with three rates of N fertilization (0, 240 and 320 kg urea-N ha-1) and two irrigation systems (furrow and sprinkler). Yield, nitrogen content, irrigation parameters, N fate and C and N isotope composition were determined. The rate of N fertilization required to obtain the same yield is considerably higher under furrow irrigation, since the crop has less N at its disposal in furrow irrigation as a result of higher loss of nitrogen by ...

India has one of the largest and most ambitious irrigation programme in the world with net irrigated area exceeding 47 million hectares. However, the overall project efficiency from the headwork to the farmer's field has been quite low which leads to not only poor utilization of irrigation potential created at huge cost, but also aggravates the degradation of soil and water resources and thereby endangers the sustainability of agricultural production system. As the cost of creating additional irrigation potential in terms of financial, human and environmental aspects has increased tremendously, need of the hour is to increase the irrigation efficiency of existing projects and use saved water for irrigating new areas or meeting the demand of non-agricultural sector. The contribution of application efficiency to poor irrigation efficiency is quite high and therefore increasing application efficiency by a shift in application method from surface to pressurized system has potential of vastly improving irrigation efficiency. To evaluate feasibility of this concept, a pilot study was initiated at Water Technology Centre for Eastern Region, Bhubaneswar, on one outlet of a minor irrigation command. The system has been designed in such a way that it provides pipe conveyance and surface irrigation for rice cultivation during monsoon season and pressurized irrigation during post monsoon period through a hybrid system of sprinkler and drip with four outlets for sprinkler irrigating 2.8 ha area and two outlets for drip irrigating 1.9 ha area. The system is also capable of providing irrigation through drip to part of a command during summer for third crop using water stored in service reservoir after the canal is closed in first week of April. To take care of sediment in the canal water, there are three stages of filtration: first by hydrocyclone filter which filters heavy suspended materials viz. sand, silt, etc., then by the sand filter and finally by the screen filter. The filtration at three stages reduces

Water Saving and Yield Enhancing Micro-irrigation Technologies: How Far Can They Contribute to Water Productivity in Indian Agriculture? Contribution of Micro-irrigation Technologies in Indian Agriculture Present Spread of Micro-irrigation Technologies in Indian Agriculture There were no systematic attempts in the past to assess the spread for water-saving irrigation technologies in India. The most recent data shows that nearly 1.3 m ha of irrigated land is under drip irrigation (Narayanamoorthy 2004b). They cited high initial cost (including mis-targetted subsidies), clogging of drippers and cracking of pipes, lack of adequate technical inputs, damage done by rodents; high cost of spare components; and insufficient extension education effort as the major problems causal of the slow rate of adoption of drips. The National Committee on Irrigation and Drainage also added factors such as salinity hazards to the list of problems (GOI 1994). Difficulty in inter-cultivation was found as another reason for non-adoption by Shiyani et al. 1999, whereas Palanichamy et al. 2002 cited joint ownership of wells as additional reason for non-adoption based on their study in Coimbatore (Tamil Nadu). However, some of the problems listed above such as clogging, lack of adequate technical inputs and high cost of spare components, to a limited extent, are being bypassed with the introduction of low-cost micro-irrigation systems in India, pioneered by international development enterprises. The recent data released by the Task Force on Micro-irrigation in India shows that during the past 4 years, peninsular India had recorded the highest growth in the adoption of drip systems. Maharashtra ranks first (22,358 ha), followed by Andhra Pradesh (17,556 ha) and Karnataka (16,731 ha). The major crops for which drip systems are currently adopted are cotton, sugarcane; banana, orange, grapes, pomegranate, lemon, citrus, mangoes, flowers, and coconut. Though exact state-wise data on the spread of sprinkler systems are not available, it has been found that sprinkler systems are in vogue in regions where conditions are unfavorable for the traditional method of irrigation, such as loose sandy soils and highly undulating fields. These are well-irrigated areas. Farmers in other well-irrigated areas have also procured the system under the government subsidy program, but were found to be using the HDPE pipes for water conveyance in the field except during droughts when they are used for providing supplementary irrigation to kharif crops. In India, sprinkler systems are mainly used for field crops such as wheat, sorghum, pearl millet, groundnut and mustard. But the use of sprinklers is often limited to certain parts of the crop season when farmers face severe shortage of water in their wells. Normally, this is just before the onset of monsoon when the farmers have to do sowing of these crops, or when there is a long dry spell during the monsoon season. Sprinklers for groundnut are common in Saurashtra in Gujarat; they are also common for mustard in Khargaon District of Madhya Pradesh and the Ganga Nagar District of Rajasthan. In the high ranges of Kerala and Tamil Nadu, sprinklers are used for irrigating tea and coffee plantations. However, recently, farmers have started using micro-sprinklers and mini-micro-sprinklers for potato, groundnut and alfalfa.

Com o objetivo de avaliar o efeito da adubação foliar nitrogenada na aclimatização de bromélia cultivada in vitro, utilizaram-se mudas de Aechmea blanchetiana, que, após o processo de cultivo in vitro, foram transferidas para substrato constituído de areia e adubadas por pulverização de 3,0 mL, a cada 30 dias, com solução de KNO3 nas concentrações de 0,0; 2,5; 5,0; 7,5 e 10,0 g L-1. Foram avaliadas as variáveis comprimento da maior folha e raiz, número de folhas, fitomassa fresca e seca das plantas e a porcentagem de plantas mortas no estágio inicial e após dois períodos de aclimatização (0; 60 e 120 dias). Concentrações maiores de KNO3 foram eficientes, amenizando os efeitos do estresse durante o período da aclimatização de 60 dias. Entretanto, ao final do experimento (120 dias), as plantas submetidas à adubação foliar com KNO3 apresentaram menor crescimento que o controle.

Articles on chemigation with fungicides targeting foliage have been reviewed. They included 23 fungicides tested on 10 crops. Many studies compared chemigation to a check treatment, while others also included conventional methods. Chlorothalonil, followed by mancozeb, fentin hydroxide and captafol were the most studied fungicides, while peanut (Arachis hypogaea), potato (Solanum tuberosum), tomato (Lycopersicon esculentum), and dry beans (Phaseolus vulgaris) were the most studied crops. Center pivot, followed by solid set, were the irrigation systems most frequently used. The minimum volume of water applied by some center pivots (25 000 litre ha-1) is 25 times the maximum volume of water used by conventional ground sprayers. The reduction of fungicide residue on foliage caused by the very large volume of water used by chemigation might be oþ set by the following factors : (1) fungicide application at the time of maximum leaf wetness when fungi are most active, (2) complete coverage of plants, (3) reducing greatly the inoculum on plant and soil surface, (4) better control of some soil pathogens, and (5) more uniform distribution of fungicides by center pivot. Furthermore, chemigation avoids mechanical damage and soil compaction. Additionally, some systemic fungicides seem to be absorbed rapidly by the leaves, by root uptake from the soil, or by both. In general, all fungicides applied through irrigation water can lessen disease severity. However, when compared to conventional methods, chemigation with fungicides can be less, equally or more eþ ective depending on crop, pathogen, disease severity, fungicide and volume of water. For Cercosporidium personatum control on peanuts, application of protectant fungicides through irrigation water is less eþ ective than conventional methods, but the results with some systemic fungicides mixed with nonemulsiüed oil and applied through a relatively low volume of water (2.5 mm) are encouraging. Important diseases of potato and tomato can be controlled nearly as well by chemigation as by conventional methods without impairing yield. The main advantage of chemigation for these crops is avoiding a large number of tractor trips through the üeld and reduced costs of fungicide application. Chemigation has also been shown to be a good option for control of white mold [ Sclerotinia sclerotiorum ] on dry beans.

companies are reflected in the price producers The economic feasibility of investing in must pay to purchase the surface water sprinkler irrigation technology for rice pro-necessary for crop production (Griffin et al.). duction is investigated using linear program-Water costs have contributed to a declining ming and capital budgeting to identify the net profit margin in recent years. The average annual benefits and net present value, respec-total cost for rice irrigation water in Texas tively. Groundwater and both fiat rate and rose from $30.00 per acre in 1977 (USDA, volumetrically priced surface water sources of 1977) to $73.58 per acre in 1982 (Griffin et al.). irrigation water are analyzed. Under typical Irrigation water was responsible for 16 to 25 practices occurring in rice production opera-percent of variable costs and 11 to 17 percent tions in the Texas Rice Belt, sprinkler irriga-of total costs associated with producing a rice tion technology is not profitable at current crop in 1982 (USDA, 1982). The current poor water costs. Producers using volumetrically profitability of rice production enhances the priced surface water have the greatest incen-need for Texas and other southern rice protive to consider sprinkler irrigation, but water ducers to be economically efficient with prices must increase by over 250 percent for respect to water as well as other production the investment in a sprinkler irrigation inputs. system to become attractive. Yield reductions Beyond satisfying rice water requirements, associated with sprinkle-irrigated rice are a the primary purpose of the conventional significant disincentive. For equivalent flood-flooding technique is to control weed growth and sprinkle-irrigated rice yields, an increase (McCauley). Creating flooded conditions, in water prices of over 175 percent is required however, consumes much more water than before the investment in a sprinkler irrigation what is required for rice plant growth. In the system becomes economically feasible. Texas Rice Belt, for example, survey response estimates of water use on flood-Key words: rice, linear programming, capital irrigated rice range from 1.7 to 7.4 feet per budgeting, sprinkler irrigation, acre (Griffin and Perry). These figures intechnology, flood irrigation. elude, in varying proportions, water consumed

Dissertação apresentada ao Programa de Pós-Graduação em Biodiversidade tropical da Universidade Federal do Espírito Santo, como requisito parcial para obtenção do título de Mestre em Biodiversidade, na área de concentração Ecofisiologia Vegetal.

RESUMO-Um sistema de irrigação deve possibilitar o manejo da água com a máxima eficácia. Para tal, é necessário avaliar o desempenho do sistema em operação. Um dos parâmetros utilizados na avaliação é a uniformidade de distribuição da água, a qual é representada pelo coeficiente de uniformidade, de Christiansen (CUC). Os valores de CUC obtidos em ensaios de campo são afetados por diversos fatores. Este trabalho teve como objetivo analisar a influência do número de linhas radiais e da altura dos emissores em relação à superfície de captação desses emissores, no valor do coeficiente de uniformidade de distribuição da água em um sistema de irrigação do tipo pivô central. Foram utilizadas três alturas de emissores (1,10 m, 1,65 m e 3,20 m) e quatro variações de número de linhas radiais de coletores (uma, duas, três e quatro). A análise dos resultados revelou diferença estatística, pelo teste de Tuckey, a 5% de probabilidade, em relação aos valores de CUC obtidos nas três alturas de emissores. Observou-se a importância do uso de duas linhas radiais de coletores, em avaliações de um sistema pivô central no campo. Termos para indexação: coeficiente de uniformidade, irrigação.

Resumo A deiscência não simultânea dos frutos de bromélias deve ser considerada para fins de propagação por sementes. O objetivo deste estudo foi avaliar o melhor método para produção de plantas da bromélia imperial considerando a colheita simultânea das sementes de diferentes posições do escapo floral no período da deiscência dos frutos da base e seu armazenamento para posterior uso na obtenção de plantas. As sementes foram colhidas da base, meio e topo do escapo floral e armazenadas por 26, 61, 154 e 213 dias a 10 °C e a 25 °C. Foram avaliadas a emergência de plantas em gerbox com papel de filtro e a germinação e crescimento in vitro com 10, 20 e 30 g.L-1 de sacarose. As sementes colhidas da base e armazenadas por até dois meses a 10 °C foram as que apresentaram maior porcentagem de emergência de plantas (57%) e a melhor concentração de sacarose para germinação in vitro foi de 10 g.L-1 e para o crescimento, 20 g.L-1. Considerando-se a vulnerabilidade desta bromélia, o aproveitamen...

Irrigation is the largest water use in the western United States. The Upper Snake Rock Conservation Effects Assessment Project in southern Idaho began in 2005 to quantify the impacts of conservation practices in this irrigated watershed. The objective of this study was to determine the changes in the watershed water balances as farmers converted furrow irrigated fields to sprinkler irrigation from 2006 to 2016. More than 75% of annual watershed inflow was irrigation water diverted into the watershed from the Snake River and distributed through canals to 82,000 ha of cropland, while annual precipitation was only 10% to 23% of the annual inflow. Approximately 30% of the annual watershed inflow flowed back to the Snake River as irrigation return flow. Water balances showed that irrigation exceeded evapotranspiration (ET) in the spring and fall, indicating that irrigation diversions could be reduced early and late in the irrigation season. Annual irrigation project efficiency, defined as ET divided by the amount of diverted irrigation water, varied from 61% to 73%, but project efficiency did not increase as the amount of cropland that was sprinkler irrigated increased from 46% in 2006 to 59% in 2016. The only significant trends indicating that increasing sprinkler irrigation impacted the water balances were increasing irrigation project efficiency in July and increasing irrigation return flow during the irrigation season. Farmers may be applying less irrigation water with sprinkler irrigation compared to furrow irrigation, which could have caused return flow to increase since irrigation diversions did not change with the supply-based water allocation. Irrigation scheduling based on soil moisture measurement or daily ET would help irrigation application match crop water needs on individual fields. For the entire irrigation project, irrigation efficiency could improve if irrigation diversions into the watershed could be adjusted to more closely match ET in the spring and fall, which may require structural changes to the canal system and policy changes for the Snake River reservoir system.

HighlightsPrivate and public irrigation development was important for expanding agricultural production in the western U.S.The Twin Falls Canal Company is an excellent example of a successful Carey Act project.Cooperative efforts during the last 30 years have dramatically improved the water quality of irrigation return flow.Electricity generated by six hydroelectric facilities improves the sustainability of the irrigation project.. Private and public irrigation development projects were fundamental to bringing irrigation to arid regions of the western U.S. The Twin Falls Canal Company in southern Idaho provides a case study of private and public irrigation development because the project was developed by private investors under the Carey Act and receives a portion of its irrigation water supply from U.S. Bureau of Reclamation reservoirs. The project survived initial financial struggles and waterlogged soil to focus on sustaining crop production by reducing chronic furrow irrigation ...

Agricultural crops grown in southern Idaho are furrow or sprinkler irrigated. Therefore, the soil experiences several wetting and drying cycles each growing season that can contribute to changes in aggregate tensile strength and friability. The objective of the research was to evaluate the influence of irrigation on soil structural properties. Four furrow-irrigated fields were sampled at the top and bottom of the field, in the furrow and on the bed location of the furrow. Five sprinkler-irrigated fields were sampled at depths of 0-5 and 5-15 cm and at the top and bottom of the field. Results from this study indicate that differences in tensile strength in furrow-irrigated fields were only evident soon after irrigation; otherwise, there were few differences in tensile strength and friability. In sprinkler-irrigated fields tensile strength increased with depth in three of the five fields measured. Friability was less affected by depth.

El riego por aspersión, al igual que los otros métodos de riego, se caracteriza por no aplicar la misma cantidad de agua en todos los puntos de la parcela regada, sino que siempre habrá algún grado de desuniformidad. Con el propósito de estudiar la uniformidad de aplicación del agua en superficie y en el suelo bajo un sistema de riego por aspersión estacionario, así como el efecto sobre el cultivo de caraota (Phaseolus vulgaris L.), se desarrolló una investigación durante los años 2008 y 2009 en el Campo Experimental de Riego del Decanato de Agronomía de la UCLA. Los resultados muestran que la uniformidad de los riegos acumulados medida sobre la cubierta vegetal (CUa) y en el perfil del suelo (CUs) fueron mayores que la uniformidad promedio de los eventos de riegos individuales, y que la uniformidad del rendimiento del cultivo de caraota tiene mayor aproximación al CUs después del riego. La variabilidad del rendimiento, de sus componentes y del índice de cosecha fue ligeramente mayor en el ciclo 2009 que en el 2008, y se debió a la mayor variabilidad de las láminas de riego acumuladas recibidas en cada subparcela de dicho ciclo.

Dünyada küresel ısınmanın etkisiyle yağışların miktar ve dağılımın değişmesi, kullanılabilir su kaynaklarını kısıtlı hale getirmektedir. Gelişmekte olan ülkeler de olduğu gibi ülkemizde de en fazla su tarımda kullanılmaktadır. 21.yüzyılda su kaynaklarının etkin kullanımı ve her damla sudan daha fazla ürün alma gerekliliği gündeme gelmiştir. Tarımda su tasarrufu sağlayan ve aynı su ile daha geniş alanların sulanmasını mümkün kılan basınçlı sulama sistemlerinin kullanımı önerilmektedir. Bu amaçla ülkemizde Gıda Tarım ve Hayvancılık Bakanlığı tarafından 2006 yılından beri basınçlı sulama sistemlerinin kurulması desteklenmektedir. Bu çalışmada, ülkemizde Gıda, Tarım ve Hayvancılık Bakanlığı tarafından basınçlı sulama sistemlerine verilen destekler incelenmiş, bu konuda görülen sorunlar ve çözüm önerileri verilmiştir.Changes in the amount and distribution of rainfall in the world due to the global warming limit the usable water resources. As in developing countries, most of the water in ...

Bu çalışmanın amacı, Yaylak Ovasının 1400 nolu yedeğinde toplu yağmurlama sulama sistemi ile toplu damla sulama sistemini projelemek ve maliyetlerini karşılaştırmaktır. Bitki su tüketimleri Penman-Monteith metodu ile hesaplanmış, sulama sistemleri planlanmış, sistem debileri belirlenmiş, sistem unsurları boyutlandırılmış ve 2004 yılı fiyatlarına göre proje keşif özetleri hazırlanmıştır. Toplu yağmurlama ve toplu damla sulama sistemleri için maliyet analizleri yapılmış, masraf unsurları, sabit ve değişen masraflar, her sistem için ürünlerden sağlanabilecek brüt gelirlerin dağılımı, sulama yatırımlarının net bugünkü değerleri ve fayda/masraf oranları hesaplanmıştır. Yağmurlama sulama sisteminde faiz oranı %15 olduğunda 1 YTL'lik yatırıma karşılık 0.72 YTL ve faiz oranı % 20 olarak alındığında ise 1 YTL'lik yatırıma karşılık 0.95 YTL'lik fayda sağlanmaktadır. Damla sulama sisteminde ise, faiz oranı % 15 olduğunda 1 YTL'lik yatırıma karşılık 1.64 YTL, faiz oranı % 20 olarak alındığında ise 1 YTL'lik yatırıma karşılık 1.94 YTL'lik fayda sağlanmaktadır. Sonuç olarak, araştırma alanında damla sulama yönteminin uygulanması önerilmiştir.

Dengan keberadaan Daerah Irigasi (D.I.) Cipta Graha diharapkan mampu memicu dan mendukung roda pertumbuhan ekonomi serta menunjang swasembada pangan di Kabupaten Kutai Timur khusunya dan Provinsi Kalimantan Timur pada umumnya. Untuk mendukung harapan keberadaan daerah irigasi tersebut, harusnya didukung oleh sistem irigasi yang baik dan terorganisir. Oleh karena itu, untuk memenuhi persyaratan tersebut Daerah Irigasi (D.I.) Cipta Graha harus memiliki jaringan irigasi yang baik sehingga mampu membawa air yang bersumber dari Sungai Kaubun yang tamping oleh bangunan Bendung Cipta Graha dan disalurkan menuju ke petak-petak sawah. Penelitian ini dilakukan mengikuti tahapan berikut ; (1) perhitungan debit andalan pada Daerah Irigasi (D.I.) Cipta Graha, (2) perhitungan kebutuhan pengambilan air maksimal untuk keperluan irigasi (3) perhitungan dan penentuan dimensi saluran irigasi yang efisien untuk mengairi Daerah Irigasi (D.I.) Cipta Graha. Hasil penelitian menunjukkan bahwa besar debit andalan pada Daerah Irigasi (D.I.) Cipta Graha yang terbesar terjadi pada bulan Februari sebesar 2,808 m 3 /det dan dari hasil analisa didapatkan pola tanam untuk Daerah Irigasi (D.I.) Cipta Graha yaitu pola tanam Padi-Palawija-Padi dikarenakan ketersediaan air irigasi dalam kategori mencukupi dengan kebutuhan pengambilan air maksimal untuk padi I adalah 1,527 m 3 /det, palawija sebesar 0,403 m 3 /det dan untuk padi II sebesar 1,186 m 3 /det, serta dimensi saluran irigasi pada Daerah Irigasi (D.I.) Cipta Graha terdapat 3 tipe desain dimensi dengan ukuran menyesuaikan dari debit rencana yang dibutuhkan oleh masing-masing petak sawah dan jalur rencana saluran irigasi Tipe pertama dengan ukuran lebar dasar saluran (b) adalah 0,445 m, lebar atas saluran adalah 1,350 m dan tinggi saluran sebesar 0,890 m. Tipe kedua dengan ukuran lebar dasar saluran (b) adalah 0,485 m, lebar atas saluran adalah 1,445 m dan tinggi saluran sebesar 0,020 m. Tipe ketiga dengan ukuran lebar dasar saluran (b) adalah 0,400 m, lebar atas saluran adalah 1,200 m dan tinggi saluran sebesar 0,840 m

This final report contains the secondary irrigation network design of Lebak Semendawai Irrigation East OKU South Sumatera. This report discusses the planning and calculation of channel dimensions both primary, secondary, or tertiary. The data plan for the writing of the final report includes a situation map data, rainfall data, and climatological data (air temperature data, the data of air humidity, wind speed data, and the data of solar radiation). The method used is the normal ratio method, algebraic method, Penmann method, and others. Has 25 Primary and Secondary Network with a total length of 19550 m using water Romijn doors, the large dimensions of the channel are at Saluran Induk Lebak Semendawai 1 (SILS.1) with width (b) 3,00 m and height (h) 0,9 m and channel dimensions parent / secondary smallest is Saluran Muka Campang Tiga 2 (SMCT2) with width (b) 0,4 m and height (h) 0,4 m. In this plan requires a fee of Rp. Rp 79.265.236.000,- the time during the 250-day labor jobs. Key...

The most problem that occurs in Cinangka Irrigation Area is the not function of sluice and not used to properly regulate water of it. If the discharge regulator is not operated properly, the provision of irrigation water has the potential to be wasteful or lacking. The purpose of this study is to determine the discharge requirements for secondary irrigation water in Cinangka, produce a design of sluice in the channel and an estimated cost of manufacture. The study was conducted in the Cinangka Irrigation Area, Cibitung Tengah Village, Tenjolaya District, Bogor Regency. The study began from April - June 2020. The results obtained were known to be evapotranspiration, effective rainfall, and irrigation needs in the secondary channel of DI Cinangka per period of irrigation for one year. The largest Eto value occurred in September of 5.8 mm / day, the largest Cheff value occurred in November of 8.4 mm / day and the largest debit of needs occurred in March of 0.6 m3 / sec. Secondary sluic...

RESUMO: O desempenho hidráulico do aspersor é bastante afetado pela pressão de operação, influenciando diretamente o raio de alcance, o perfil de distribuição e a uniformidade de distribuição de água. Assim, o objetivo deste trabalho foi avaliar a uniformidade de distribuição da água aplicada em irrigação por aspersão convencional, operando nas pressões de 10; 15; 20 e 25 m.c.a, sendo realizado três repetições cada pressão de operação e sobreposição das lâminas de água com o espaçamento de 6 x 6m. Para a determinação dos valores de distribuição de água, ao longo das diversas pressões de serviço, utilizaram-se os Coeficientes de Uniformidades de Cristhiansen (CUC) e Coeficiente de Uniformidade de Distribuição (CUD). Este trabalho foi realizado na área de avaliação de uniformidade de distribuição de água em aspersão convencional, localizado ao lado do laboratório de hidráulica e física do solo, do Instituto Federal Goiano (IF Goiano), Campus Urutaí-GO, utilizando para coleta da lâmina precipitada 144 coletores ficando 20 cm do solo, equidistantes em torno de um aspersor instalado no centro da área a 1,40m altura, formando um quadrante com coletores espaçados entre si de 2 x 2m. Os resultados obtidos para o espaçamento (6x6 m) demonstram que ocorreu aumento da média geral dos valores de CUC e CUD à medida que houve aumento na pressão de serviço do aspersor. Os valores de CUC e CUD de melhor qualidade foi para pressão de 25 m.c.a (96,28% e 95,21%, respectivamente). A dependência espacial da distribuição de água em aspersão convencional foi constatada por meio dos modelos variográficos. O melhor ajuste foi para pressão de 25 m.c.a com o modelo de semivariograma isotrópico gaussiano (R²=1,00), porém, as outras pressões estudadas (10, 15 e 20 m.c.a) ajustaram-se melhor no modelo de semivariograma isotrópico esférico.

The objectives of this study were to develop an equation for the ponding time, t p , and determine the number of on-off cycles using the infiltration equations introduced by Horton and Kostiakov and to compare the observed and predicted ponding times t p. To achieve these objectives, a sprinkler infiltration test was conducted on the Harran soil series at the Sanhurfa-Koruklu, Tubitak Agricultural Research and Development Station on the Harran plain. The soil characteristic parameters of the Horton and Kostiakov equations were determined from the results of sprinkler infiltration tests. The ponding time equations were developed by choosing a sprinkler application rate of i s = 13.61 mm h À1 that is higher than the steady-state infiltrability rate of i ss = 7.1 mm h À1. The number of on-off cycles was then determined from repeated cycles. The ponding times t p for the experiment, the Horton equation, and the Kostiakov equation were 4.17, 4.09 and 2.69 h, respectively. The numbers of on-off cycles for all three methods were estimated to be two. Under the same management conditions, it was concluded that irrigation at a rate i s > i ss could be completed in 44% less time without the occurrence of runoff and erosion.

Strawberry (Fragaria ×ananassa) crops were transplanted in two seasons in central Florida with bare-root and containerized (plug) plants under three transplant establishment-period irrigation methods to evaluate crop fruiting responses and production economics associated with the various establishment systems. Irrigation was not required to establish plug transplants in the fi eld. Early (fi rst 2 months) fruit yield with nonirrigated plug plants was greater than early yield with sprinkler-irrigated bare-root plants (the current commercial system) in one of two seasons and equal in a second season. Total-season yields were similar in each season between the two establishment systems. Large or medium plug plants led to greatest early fruit yields in one season while large plug plants resulted in greatest early yield in a second season. Total yield was greatest with medium plants in one season and large plants in another season. The extra cost for the plug plant system was $1853/acre. In one out of two seasons there was increased net income amounting to $1142/acre due to greater early yield associated with the plug plant cultural system. Strawberry plug transplants showed promise for earlier and more profi table crops in addition to substantial savings in water used for plant establishment in the fi eld. The ability to establish strawberry crops without irrigation will be important in areas where growers are required to reduce farm water consumption.

Experiments were conducted in two seasons in Dover, Fla. (central Florida), with bare-root and containerized (plug) strawberry (Fragaria ×ananassa) transplants to evaluate transplant establishment-period water use, plant growth, and fl owering responses in the 3-week transplant establishment period. Strawberry plug plants were established with 290 gal/acre water applied only with the transplant at planting time, while 200,000 gal/acre from microjet or 1 million gal/acre of water from sprinkler irrigation were used to establish bare-root transplants. Root, shoot, and crown dry matter of plug plants rapidly increased during the establishment period, while there was a decline in leaf area and root and crown mass of bare-root plants, even with sprinkler or microjet irrigation. Water applied with the bare-root transplant only at planting was not enough to keep the plant alive during the establishment period. Large plug plants, but not irrigated bare-root plants, began fl owering at 3 weeks after planting. Plug plants were used to successfully establish strawberry crops with low water inputs.

Water flowing in irrigation furrows detaches and transports soil particles and subsequently nutrients such as phosphorus (P). To reduce the risk of erosion and offsite P transport, producers in south-central Idaho have been converting from furrow to sprinkler irrigation. We completed research on soil P dynamics in furrow versus sprinkler irrigated soils from four paired-fields in the region. Surface soils (0-2.5 inches) were obtained from fields in September following barley harvest. Furrow irrigated soils contained 38 parts per million (ppm) of plant-available P (i.e. Olsen-extractable), on average, as compared to 20 ppm under sprinkler irrigation. These results are important as 20 ppm extractable P can be construed as the point where soil P is considered low to medium in soil testing; extractable P values over 40 ppm limit sites to P application based on crop uptake only. These soils were also analyzed using a sequential extraction technique, and total and amorphous Fe were determined to identify inorganic P pools. Soils under furrow irrigation had greater concentrations of inorganic P in the soluble/Al-bound/Fe-bound and occluded phases, and in the amorphous Fe phases. Phosphorus concentrations in all other soil phases were similar between the two irrigation practices. Findings suggest that Fe redox chemistry plays a large role in P release under furrow irrigation, even in aridic systems. In terms of soil P, results support the use of sprinkler irrigation as a best management and conservation practice.