Agricultural Production

There is global concern regarding access to energy, especially in developing countries, as set forth in the Sustainable Development Goals. Although Peru is classified as an emerging economy and would be expected to have achieved full energy coverage, the status of the access to fuels in Peru is unknown. The objective of this study was to comprehensively document the instruments and the progress made on the issue of access to modern fuels and technologies for cooking in Peru to explain the current situation and to highlight the main challenges that the country must face to achieve total access to modern energy sources. A comprehensive literature review was carried out for this work, covering a wide range of publications from 1983 to 2019. A total of 18 political and economic instruments and 95 voluntary instruments were analyzed. It made it possible to build a historical series of the main events leading to access to modern cooking fuels in Peru and to identify eight key challenges. ...

Cynara cardunculus L. has been recognised as an energy crop for rainfed lands with Mediterranean climates. For energy purposes, it is grown as a permanent crop and the whole aerial biomass produced over the annual growth cycle is harvested every year. In this work, the potential of C. cardunculus L. as an oil crop is studied in a perennial cultivation system. The degree of variation of seed oil content and fatty acid oil composition is assessed in two experiments designed to study the e ect of the factors: plant population, crop year and experiment location. The range of values of seed oil content was greater for the multilocal experiment (20.0-31.6%) than for the experiment on populations (22.0-28.8%), but the e ect of the agricultural year was noticed in both experiments. There were signiÿcant di erences in the 18 populations experiment and a group of 5 populations was identiÿed as rich in seed oil (¿26%). Seed presscake was analysed and as a result the use of this material as fertiliser or as animal feed was proposed. Finally, the degree of variation of fatty acid oil composition-studied for the factors population, location and year-turned out to be rather small. Cynara oil proÿle was characterised in terms of major fatty acids as: 10.7% palmitic, 3.7% stearic, 25.0% oleic and 59.7% linoleic.

Herbaceous biomass like Cynara is commonly high in potassium, chlorine and ash, which has been reported as a source of problems for combustion applications. An appropriate management of the potassium fertilisation is suggested as a way of improving the quality of the Cynara biomass for solid fuel applications. In this work a factorial experiment was designed involving two types of fertilisers, KC1 and K 2 S0 4 , and two K rates, in order to study the effect of potassium fertilisation on the composition and thermal behaviour of Cynara biomass. The results proved that the potassium content of Cynara biomass increases with the potassium fertilisation. The thermogravimetric study showed that sintering phenomena can be expected at temperatures higher than 900 °C when the crop has been highly K-fertilised, irrespective of the type of fertiliser used, KC1 or K 2 S0 4. However, the SEM images taken of samples of the four K treatments of this experiment did not reveal signs of ash melting, although some particles with crystalline appearance appeared in the samples from highly K-fertilised treatments. 2.1. Field experiment The field trials were carried out in the 2003-04 season in the Experimental Fields of the Agroenergy Group of the Polytechnic University of Madrid, Spain (latitude 40o26'36"N, longitude 3o44'18"W, altitude 595 m). The experiment design for the field trials was: 2 potassium rates x 2 types of potassium fertilisers (KC1 and K 2 S0 4) x 3 replications, plus the control (non-K-fertilised treatment).

Sweet sorghum (Sorghum bicolor (L.) Moench) has been recognized as an alternative crop for energy purposes. In the central area of the Iberian Peninsula, its main growth period coincides with the dry season and irrigation is needed for reasonable sorghum productivity. Knowledge of irrigation-yield relationships is fundamental, since water is a scarce resource there. Our objectives in this work were to study the effect of water regime on the productivity and water use efficiency (WUE) in a sweet sorghum cultivar "Keller" grown in lysimeters in Madrid. Experiments were carried out during three crop cycles. Three irrigation regimes: HI, HZ and Hx, corresponding to a water supply of 5.7, 11.4 and 17. I dm' m I day-' were experimented with during the main growth period. Maximum aerial biomass production was 4.0 1O'g DM rn-? in the HJ regime. WUE was quite similar for every irrigation regime but varied between sorghum seasons. 4.6 g aerial biomass DM dm-3 was obtained as the average for a crop cycle length of approximately 130 days. The water regime did not clearly affect the sugar content in stalk sections. The mean value of sugar content in whole stalks was 41.4% w/w on a dry-weight basis. The ratio of ethanol production to evapotranspired crop water was estimated at 0.63 g dm-' (mean value).

An experiment was conducted to study the potential of 12 clones of Helianthus tuberosus L. for the production of bioethanol from the stems. Aboveground biomass production and total sugar content of the whole stems were determined at three phenological growth stages: flower bud, full bloom and dry head. The potential of the tubers for bioethanol was determined as well, in order to compare the two possible crop applications. Results showed that the performance of the early clones for the use of the stems was different from the mid-season/late clones. The aboveground biomass production and mean tuber weight of the early clones were lower than for the other clones and the period between the stages of flower bud and dry head much shorter. Stem sugar content of the early clones decreased after the full bloom stage; the trend observed for the other clones was that the decrease happened after the flower bud stage. The final tuber production of the early clones was generally lower. Mid-season/late clones showed a higher potential yield of sugars-and therefore, higher potential for ethanol production-whether they were cropped for the stems or for the tubers. Comparing the values obtained for these two applications of the crop, it was estimated that the potential of the stems of the mid-season/late clones for bioethanol was 38% that of the tubers.

The capitula of Cynara cardunculus contain hairs and pappi representing 7% of the total plant biomass. These low density biomass components could be mechanically separated without apparent losses using a whole-plant processing prototype. Hairs and pappi are filamentous structures made up of longitudinally aligned fibre cells, without intercellular voids or pitting, with the following dimensions regarding length, width and wall thickness: 1.35 mm, 19.8, and 4.8 m for hairs and 1.78 mm, 10.4, and 2.9 m for pappi. Chemically hairs and pappi have low content of ash (1.9% and 1.1%, respectively), extractives (5.4% and 6.0%) and lignin (10.6% and 17.8%), and high content of holocellulose (77.5% and 72.8%) and ␣-cellulose (55.2% and 46.8%). Pulps could be produced using a conventional kraft process with high yields and low residual lignin, e.g. 63% at Kappa 7 for hairs and 48% at Kappa 11 for pappi, low coarseness values (0.04 and 0.03 mg m −1) and adequate pulp properties for paper (40 and 42 N mg −1 tensile index; 3.6 and 3.4 kPa m 2 g −1 burst index in unrefined pulps of hairs and pappi, respectively). The results also indicated that there is scope for improving pulp quality by optimising pulping conditions to this type of new raw materials. The differences between hairs and pappi may also be further exploited namely the lower lignin content of hairs and the higher slenderness and wall thickness of pappi fibres. The utilization of hairs and pappi may strengthen the differentiated use of biomass fractions of the Cynara plant and its potential as a bioenergy crop.

Sweet sorghum (Sorghum bicolor L.) is considered one of the most promising crops for bioethanol production in many countries and is a focus of bioenergy research worldwide. In July 2011, plants of the sweet sorghum cv. Suchro 506 in Oropesa (Toledo, Spain, 40.048577°N, 5.360298°W) (European Datum 1950 UTM zone 30 N) were observed with severe wilting. Upon examination, the lower internodes were found to be straw colored. When the plant was split, the internal pith was reddish, soft, and disintegrating. Small pieces of symptomatic stems and roots were surface disinfected in sodium hypochlorite (0.5% wt/vol) for 2 min and air dried. The sections were then placed on either PDA (potato dextrose agar) medium or Komada agar and incubated for 5 days at 25°C. Isolations from diseased stem and root tissue consistently yielded Fusarium verticillioides (Sacc.) Nirenberg (3). The small, hyaline, mostly single-celled, oval to club-shaped microconidia of F. verticillioides were produced in long ca...

This work aims to identify the sources of nitrogen contamination in nitrate vulnerable zones (NVZs) of Spain by means of the nitrogen isotope method. Three categories of nitrogen sources (synthetic fertilisers, animal wastes, and sludges and effluents from waste-water treatment plants) from three NVZs were analysed for their nitrogen isotopic composition (δ 15 N) in order to assess the applicability of the method to the identification of these N sources. The mean δ 15 N values were: +1.48 for synthetic fertilisers, +15.98 for animal wastes and +11.52 for sludges and effluents. The synthetic fertiliser sources were significantly different from the organic sources and so, the method can be used for their identification. The highest variability was found within the animal waste category. The range of values found for the different kinds of animal wastes (+5.86 to +36.74) was very wide and overlapped the range found for sludges and effluents from waste-water treatment plants (+4.57 to +20.18). Accordingly, these two nitrogen sources are isotopically indistinguishable.

A three-year experiment on Cynara cardunculus under rainfed conditions was conducted in a 10-ha field of poor soil quality, as a contribution to the EU Project 'Bio-Energy Chains'. Crop conditions were marginal in that soil, a Calcic Haploxeralf, and climate, Xeric Mediterranean, were limiting factors for plant growth. Climate conditions were particularly severe during the third crop cycle, with frosts of up to -18.5ºC and 228 mm annual precipitation. The experiment showed that C. cardunculus endures harsh conditions and yields acceptable amount of biomass.

Cardoon (Cynara cardunculus) stalks were submitted to steam explosion (183ºC, 5 min) with a 18 yield of 88%, and a lignin loss of around 7%. Cardoon (C) and steam exploded cardoon (C SE) 19 were characterized by wet chemical analysis and Py-GC/MS. Total lignin and its S/G ratio were 20 21.6% and 1.35 in C; and 22.4% and 1.40 in C SE. These samples were delignified by kraft and 21 organosolv processes. Cardoon pulps were obtained with different yields of 45.1% for kraft and 22 61.2% for organosolv. Kraft pulps yields were 45.1% and 50.9% respectively for C k and C SE-K , 23 corresponding to a lignin loss of 74.7% and 72.2%. The S/G ratio was similar 1.25 and 1.23. 24 Organosolv pulps presented higher yields (61.2% vs. 73.3%), were less delignified (30.5% vs. 25 13.8%), and the S/G ratio was 1.54 and 1.47 respectively for C org and C SE-org. Overall, the 26 condition chosen for steam explosion allowed a low mass loss, but did not promote 27 delignification and neither enhanced lignin removal during kraft and organosolv processes.

This review covers 30 years on cardoon (Cynara cardunculus L.); a perennial plant adapted to the Mediterranean climate conditions of low rainfall and hot dry summers. Its potential as a non-food agricultural crop for set-aside lands and the excellent biomass production created an enthusiastic research interest in this plant and its uses. The review starts with the plant morphology, ecology and development, followed by the agricultural aspects related to crop establishment and harvest, giving the available data on the production yields by biomass component, from small research plots to large-scale plantations. The biomass components are characterized regarding anatomical, chemical and physical properties in view of their use as feedstock for the different applications. The use of Cynara biomass for energy was assessed according to its fuel properties and performance under the various processes e.g. combustion, gasification and pyrolysis. Cynara seeds contain a linoleic acid rich oil that may be processed into a biodiesel with properties similar to commercial diesel. The production of biomethane and of ethanol were also studied with promising results. Cynara was tested as a fibre source for production of pulp and paper using different delignification processes (kraft, soda, ASAM and organosolvs) with good pulp yields and adequate physical and mechanical properties. More recently, the phytochemical and pharmacological activities of different compounds extracted from Cynara biomass are also being investigated. This plant is a good candidate to be grown in the dry lands of the Mediterranean region as a perennial field crop for multi-purposes and non-conventional uses.

Arundo donax L., commonly known as giant reed or arundo, is a perennial rhizomatous grass that has been studied since the decade of 1980 for bioenergy. In the Mediterranean regioncharacterised by dry and hot summers-arundo is usually grown with the support of irrigation. However, there is evidence that this plant species can tolerate dry-farming conditions once the crop is fully established. In this work the variation observed in plant growth of a 5-yearold arundo crop when the management changed from irrigated to dry-farming, is assessed. The hypothesis underlying this work was that punctual variations of soil properties might be responsible for the differences observed in plant growth.

This work gives an overview of traditional and alternative applications of Cynara cardunculus L. The traditional applications are the use of the blanched stalks as an edible vegetable and the use of the flowers as a rennet substitute to make cheese. Alternatively, C. cardunculus can be cultivated as an energy crop and be used for industrial purposes. As an energy crop it is grown using a perennial cultivation system especially developed for producing biomass. The valuable crop produced in this case is the whole aboveground biomass. Two types of products can be harvested: lignocellulosic biomass and oil seeds. Cynara lignocellulosic biomass is a solid biofuel that can be used directly for heating or for electric power generation. The seeds, due to their high oil content, can also be used for energy applications, for example, as raw materials for biodiesel production. In addition to the energy applications of the crop, other alternative applications, such as green forage for ruminants, paper pulp production and pharmacological active compounds extraction, are also discussed.

Cynara cardunculus L. was installed for biomass production in a total of 8.1 ha in Sesimbra (Portugal), using common agricultural practices and machinery. Installation by sowing was successful, in spite of the extreme drought during the first cycle (only 382 mm). In the second year, the rainfall was 683 mm and the plants developed well, with a mean density of 30 thousand plants per ha. The field presented a heterogeneous distribution of cardoon plants and the aerial photographs showed that 4.9 ha presented an occupation over than 50 %. The yield of biomass was 9.7 tha-1 , with plants presenting on average, 2.2 m height, 2.3 cm stalk diameter, and 6.5 capitula per plant. The capitula contained on average 210 seeds, weighing 28 g per 1,000 seeds, and the mean seed yield was 1,065 kg ha-1. The stalks represented 58.7 % of total dry biomass. These results confirm that Cynara crops are suitable for biomass production in Mediterranean regions and that large scale operation can be applied including whole plant harvesting or plant fractionation for seed recovery. There was variation between plants, namely in oil seed production, which suggests potential improvements through breeding.

A population of cultivated cardoon (Cynara cardunculus var. altilis DC) was grown in Madrid (Spain) as a reference crop to select outstanding individuals for energy applications. The work was carried out within the frame of the Spanish funded projects PROBIOCOM (INIA) and FP13-ENER. Seeds for this work were produced by one of the partners of PROBIOCOM-the Agro-Energy Group of UPM-and came from a clonal crop (in vitro propagated plants) previously grown in Madrid. IMIDRA, as Head of that Project, established the reference crop according to the protocol for cardoon energy crop and was responsible for the crop. Seeds were sown in seed trays and once the plants had true leaves they were transplanted into the field. Collection of field data involved 449 individuals at the rosette stage and the dataset comprised the measurement of plant height, rosette diameter and leaf length; leaf type was determined as well. Individuals exhibiting larger leaf size were selected and categorized into two categories: undivided-like leaf blade (16 individuals) and pinnately lobed leaf blade (12 individuals). For these individuals, leaf fresh weight, number of leaves and leaf length of previously selected leaves were determined. Furthermore, three measurements were performed with a SPAD chlorophyll meter and the Munsell color chart. Morphological features were taken according CPVO-OCVV and UPOV protocols. Most plants exhibited pinnately leaves which generally resulted in larger sizes than the undivided-like leaf plants. Results suggested that the morphological plant type could be used as a preliminary selection criterion of C. cardunculus for biomass production; however, further studies are needed at harvest time to confirm this trend.

Large scale cultivation of the cardoon Cynara cardunculus L. for biomass production was installed using common agricultural practices and machinery in a total of 77.4 ha in southern Portugal in a region characterized by very hot and dry summers. This species is a perennial with an annual growth cycle. Installation by sowing was successful in spite of the extreme drought that occurred during this first cycle (221 mm), and the plants developed well during the second cycle (with 556 mm rainfall) with a mean density of 27 thousand plants per ha. Aerial photographs showed that 45.8 ha of the field had over 50% of ground cover by cardoon plants. The observed differences in soil occupation could be explained by rock outcrops, soil heterogeneity and land topography. The field biomass yield was estimated at 7.5 t ha −1 and the plants at harvest had on average 2.1 m height and 2.2 cm stalk diameter, with 5.3 capitula per plant. Stalks represented 59.1% of total dry biomass. The capitula contain small oil seeds with an average of 126 seeds per capitulum and weighing 32 g per 1000 seeds. The mean seed yield was 603 kg ha −1. The results of this experiment confirm that Cynara crops are suitable for biomass production in Mediterranean regions and that large scale operation can be applied including whole plant harvest or field fractionation for seed recovery. Careful attention to cultural practices was deemed important for field homogeneity and production. The observed plant variation, namely in oil seed production, suggests potential improvements through breeding.

Carbon distribution in the stem of 2-year-old cork oak plants was studied by 14 CO 2 pulse labeling in late spring in order to trace the allocation of photoassimilates to tissue and biochemical stem components of cork oak. The fate of 14 C photoassimilated carbon was followed during two periods: the first 72 h (short-term study) and the first 52 weeks (long-term study) after the 14 CO 2 photosynthetic assimilation. The results showed that 14 C allocation to stem tissues was dependent on the time passed since photoassimilation and on the season of the year. In the first 3 h all 14 C was found in the polar extractives. After 3 h, it started to be allocated to other stem fractions. In 1 day, 14 C was allocated mostly to vascular cambium and, to a lesser extent, to primary phloem; no presence of 14 C was recorded for the periderm. However, translocation of 14 C to phellem was observed from 1 week after 14 CO 2 pulse labeling. The phellogen was not completely active in its entire circumference at labeling, unlike the vascular cambium; this was the tissue that accumulated most photoassimilated 14 C at the earliest sampling. The fraction of leaf-assimilated 14 C that was used by the stem peaked at 57% 1 week after 14 CO 2 plant exposure. The time lag between C photoassimilation and suberin accumulation was ~8 h, but the most active period for suberin accumulation was between 3 and 7 days. Suberin, which represented only 1.77% of the stem weight, acted as a highly effective sink for the carbon photoassimilated in late spring since suberin specific radioactivity was much higher than for any other stem component as early as only 1 week after 14 C plant labeling. This trend was maintained throughout the whole experiment. The examination of microautoradiographs taken over 1 year provided a new method for quantifying xylem growth. Using this approach it was found that there was more secondary xylem growth in late spring than in other times of the year, because the calculated average cell division time was much shorter.

Purpose Banana is one of the most important fruit crops in the world. The plant bears one bunch in its life, leaving behind a large amount of agricultural residues (starchy and lignocellulosic biomass), which could be used for different purposes such as bioenergy. Ecuador is the largest exporter of banana fruits. Methods In this work, the potential of banana residual biomass produced in the province of El Oro, Ecuador for bioenergy applications was assessed using Geographic Information Systems-GIS. The methodology included the assessment of biomass distribution, facility location, transport optimization and a novel virtual land parcel that allows for these kinds of studies in areas with lack of georeferenced information. Results According to our approach, El Oro province has an available biomass potential of 190,102 t fm year-1 of starchy residual biomass and 198,602 t dm year-1 of lignocellulosic residual biomass. Two candidate points located at 79°51 0 12 00 W3°11 0 21 00 S and 79°52 0 49 00 W3°17 0 49 00 S were identified for the installment of energy conversion facilities supplied with residual biomass. Conclusions From the available potential of starchy biomass it would be possible to obtain up to 19 million liters of bioethanol per year assuming an average yield of 101.2 l t-1 fresh matter; while the available lignocellulosic biomass, which energy content (Lower Heating Value, moisture free biomass) was determined at 12.9 MJ kg-1 on average, could be used for power generation with an installed capacity of 18 MW. Chemical characterization of the lignocellulosic biomass suggested that further studies should be undertaken regarding the potential application of these crop residues to second generation bioethanol.

Growing energy crops on marginal land has been promoted as a way of ensuring that biomass production involves an acceptable and sustainable use of land. Saline and saline‐prone agricultural lands represent an opportunity for growing energy crops avoiding the displacement of food production and contributing to restoration of degraded land. Giant reed (Arundo donax L.) is a perennial grass that has been proposed as a promising energy crop for lignocellulosic biomass production while its tolerance to salinity has been proved. In this work, the identification of surplus saline lands that could be irrigated with saline waters for growing tolerant‐energy crops (giant reed) in the mainland of Spain and the assessment of the agronomically attainable yield in these limiting growing conditions were undertaken. To this purpose, a GIS analysis was conducted using geodatabases related to saline areas, agro‐climatic conditions, irrigation water requirements, agricultural land availability, restri...