Straw Content Research Articles

Assessing the nutritional quality of fungal treated wheat straw: Compounds formed after treatment with Ceriporiopsis subvermispora and Lentinula edodes

A variety of secondary metabolites are formed and compounds released during the bioconversion of lignocellulosic biomass by white-rot fungi that can affect the nutritional value and acceptance of the biomass by ruminants. Changes in pH, ergosterol content, fibre and metabolites composition of wheat straw (WS) incubated with either Ceriporiopsis subvermispora or Lentinula edodes for up to 8 weeks were investigated. With increases in mycelium content, significant decreases in absolute amount of hemicellulose, acid detergent lignin and, to a lesser extent, cellulose were observed in both fungal treatments. Acidification mainly occurred within the first four weeks of incubation, coinciding with the largest changes in metabolites profile. Diverse compounds, including organic acids and soluble sugars increased or decreased with C. subvermispora and L. edodes treatment. None of the thirty-four common mycotoxins analyzed were detected in WS after 8 weeks of fungal incubation. These results provide important information for application of fungal treated WS that might affect animal acceptance and performance.

Degradation of lignocellulosic content of rice straw using aerobic cellulolytic bacteria isolated from forest soil of Bangladesh

The present research work was conducted to enumerate and isolate aerobic cellulolytic bacteria from forest soil using carboxymethyl cellulose (CMC) as substrate. The identified isolate was further tested as potent candidate to improve the nutritional value of rice straw. The forest soil was loaded with substantial amount (2.45×107) of cellulolytic bacteria. A total of 10 cellulose degrading bacteria (CDB) were isolated, identified and monitored for their cellulolytic activity. The isolate having the highest cellulolytic index (2.5) was identified as Bacillus subtilis targeting the 16S rRNA gene which was labeled as B. subtilis strain CDB7 and investigated for nutritional improvement of rice straw. Solid state fermentation of each group was carried out at 37°C for a period of 0, 3 and 6 days in 0 (no bacterial inoculum), 1, 5 and 10% inoculum group. There were a tendency of reduction in Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF) and lignin at concentrations of 1, 5 and 10% inoculums at every interval of fermentation. Highest reduction of ADF (4.8%), NDF (10.78%) and lignin (37.6%) were observed after 6 days of fermentation at 10, 10 and 5% inoculum group, respectively. The crude protein content was increased (5.3 ± 0.4 to 6.4± 0.3) in 10% inoculum group. Taken together, the identified isolate could be a potent candidate to degrade lignocellulosic content through breaking of lignin-cellulose bondage and to improve the nutritional value of rice straw. Key words: Rice straw, Bacillus subtilis strain CDB7, solid state fermentation, acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin.

Research of passage capacity of combine harvesters depending on agrobiological state of bread mass

The limits of reducing the numerical values of the coefficients of the influence of straw content, moisture, grain contamination, on the change in the throughput of the threshing-separating device and the productivity of the combine are calculated. The boundaries of the probable numerical values of the coefficients of straw content, moisture content and dockage of grain stand have been calculated. The probable boundaries of the numerical values of productivity after an hour of network (ha/h) were calculated, depending on the influence of single and general coefficients. The method for calculating the productivity of combines, depending on the weight of the influence of individual coefficients or their overall effect, is proposed, which will make it possible to predict the likely change in productivity in a particular field and during the harvest period with minimization of biological crop losses. To obtain the resulting coefficient of influence of the state of grain, it should be taken into account that the direction of change in the value of the coefficient of influence must coincide with the direction of its influence on the throughput. That is, the minimum value of moisture, straw content and debris corresponds to the maximum value of the throughput of the threshing-separating device.

Modeling the throughput capacity of threshing-separating apparatus of grain harvester’s combines

The statistic proposes the analytical provisions and the experimental results of the throughput capacity of the threshing apparatus of grain harvesters, from the capacity of straw, grain, straw content, blockage of design characteristics. The threshing capacity is most significantly affected by weediness due to humidity, with a relative weediness of 0.05 bread weight, the capacity of the threshing machine is reduced by 2.5%, and with 50% weed by 16%. Loading of the threshing machine determines the productivity of the combine and fuel efficiency due to fuel consumption for harvesting 1 hectare, as well as threshing 1 ton of crop. The power of the combine engine is designed to perform work in extrem econditions, as a result, the average loadis 2/3 of full. During the operation of the combines, the time is only 45…50% of the total operating time of the engine. Underemployment of the engine leads to overconsumption of fuel. So, if the SMD-21M diesel at full operational power of 103 kW consumes fuel of 0.24 kg on 1 kW for an hour, at loading on 50% 51 kW s. specific fuel consumption increases by 41 g/kWh, or 17%, which corresponds to fuel consumption 2.1 kg/year.

Growth, symbiotic traits, productivity and nutrient uptake as influenced by dose and time of nitrogen application and Rhizobium inoculation in mungbean [Vigna radiata (L.) Wilczek

A field experiment was conducted to study the response of mungbean to dose and time of nitrogen (N) application and Rhizobium inoculation. Application of 12.5 kg N ha−1 + Rhizobium inoculation recorded the plant height, plant dry weight, root length, root dry weight, number of pods plant−1, 100-seed weight, biological yield and grain yield either significantly higher or statistically on par with N application at 12.5, 25, 50, 100, 50 + 50 kg ha−1 and Rhizobium inoculation alone. Nodulation, in general, decreased with increase in N dose, and was found to be significantly higher with application of 12.5 kg N ha−1 + Rhizobium inoculation than under different doses of N application. Although application of 50 kg N ha−1 produced the highest number of pods plant−1 and 100-seed weight, resulting in the highest grain yield but it was on par with 50 kg N ha−1 + Rhizobium inoculation and other nitrogen levels. Application of 50 kg N ha−1 recorded the highest N content in grain and its uptake by grains whereas the highest N content in straw and its uptake by straw as well as by the crop was recorded in treatment receiving 100 kg N ha−1. It can be concluded that application of N beyond 12.5 kg ha−1 is not beneficial in mungbean in terms of grain yield and environment point of view and integrated use of 12.5 kg N ha−1 along with Rhizobium inoculation is the most efficient in terms of high nodulation and grain yield.

Growth, yield and nutritional content of finger millet (Eleusine coracana L.) as influenced by pranic energy application

Pranic agriculture (PA) is an ancient farming method where pranic energy improves crop production. Finger millet or Ragi (Eleusine coracana. L) is a major staple millet consumed in India, particularly Karnataka and is a rich source of protein and nutrients. A field study in half-acre was carried out with pranic energy treatment to seed, land and crop and along with control (without energy treatment). The traits of finger millet like plant height (26%), number of productive tillers (35%), no of panicle (54%), number of fingers (13%) and grain yield (44%) were statistically (p < .05) higher over control. Protein content in finger millet straw (4.38 %) and grain (6.13%) was higher in pranic treatment than control (3.5 and 4.75%). Nitrogen and zinc content in millet grain was higher in pranic treatment (980 and 1.96 mg/100g) than control (760 and 1.63 mg/100g). The increase in protein, nitrogen and zinc content of the millet grain and straw will help to improve the quality of produce for consumption by cattle and humans. Increase in straw and grain yield will help to improve the economy of the farmer. Further studies are needed to know the actual mechanisms involved in the growth and yield improvement of finger millet. And, also in-depth studies are necessary to address the reasons behind the variation in nutrients accumulation in straw and grain.

Content and potential of rice straw as a mineral source of zinc in ruminant feed

Zinc is essential for growth and cell division (mitosis and meiosis), sperm production, embryo development, and pregnancy. This study aims to determine the Zinc content of three rice varieties and their potential as ruminant feed. The research was done in Central Lampung in June 2020. The experiment used a randomized block design with three varieties and three replications. Each variety (Inpari IR Nutrizinc, Ciherang, Inpari 32) was planted in 50 m2. The variables are plant height (cm), stump height (cm), straw height (cm), straw weight and grain (kg), straw weight/50 m2 (kg), straw weight/ha (kg) and the Zn content in straw. The data obtained were analyzed using the R statistic. The result did not significant differences in all variables. However, Inpari 32 has the highest average plant height, stump height, straw height, and grain weight, while Inpari IR Nutrizinc has the highest average straw weight/ha (7,970.67 ± 1,135.84 kg). The zinc content of Inpari IR Nutrizinc was also the highest at 49.85 ppm/10 g, followed by Inpari 32 (35.40 ppm/10 g), and the lowest was Ciherang (34.08 ppm/10 g). In conclusion, rice straw of Inpari IR Nutrizinc has the potential to be used as a ruminant feed.

Improvement of nutritional quality of ruminant feed composed of soybean straw and ryegrass hay

The purpose of this study was to increase the nutritional value of two raw materials (soybean straw and ryegrass hay), in order to propose the use as feed for ruminants. Different technologies were used to develop the animal feed: addition of proteins, addition of Spirulina platensis biomass, solid state fermentation by Aspergillus niger, encapsulation of microalgae biomass (capsules with xanthan gum and chitosan), as well as the control tests. The chemical composition (moisture, crude protein, lipids, ash, crude fiber, neutral detergent fiber and acid detergent fiber) of the different treatments was determined. Although the solid state fermentation using the fungus Aspergillus niger did not decrease the fiber content, the addition of microalgae biomass in soybean straw and ryegrass hay improved the quality of bulky feed, increasing until 87% and 80% protein content of soybean straw and ryegrass hay, respectively. Furthermore, the addition of Spirulina biomass in soy straw, with gelatin or encapsulated, decreased the content of neutral detergent fiber and acid detergent fiber. The bypass protein obtained using the encapsulated biomass allows the use of agro-industrial waste, adding nutritional value to bulky feed, which may increase the milk production by lactating cows.

Effects of starter protein content and alkali processing of wheat straw on growth, ruminal fermentation, and behavior in Holstein calves

The present study was conducted to investigate the effects of crude protein (CP) content of starter feed and wheat straw (WS) processing on growth performance, digestibility, ruminal fermentation, and behavior of Holstein calves. Sixty calves (28 male and 32 female) were randomly assigned to 1 of 4 treatments in a randomized complete block design. Treatments in a 2 × 2 factorial arrangement were (1) lower-CP ground starter feed mixed with alkali-processed WS (LP-PWS), (2) lower-CP ground starter feed mixed with unprocessed WS (LP-WS), (3) higher-CP ground starter feed mixed with alkali-processed WS (HP-PWS), and (4) higher-CP ground starter feed mixed with unprocessed WS (HP-WS). Wheat straw was fed at 4.75% of dry matter (DM), and low-protein (LP) and high-protein (HP) starter feed contained 19.5 and 23.5% CP, respectively. The calves were weaned on d 60 and remained in the study until d 75. During the experiment, the calves received 4.2 kg of whole milk per day and had free access to fresh water and starter feed. The interaction between WS processing and protein content of starter tended to be significant for starter feed intake, average daily gain (ADG), and body weight (BW); calves fed HP-PWS tended to have greater ADG and final BW than other treatments. The results showed that feeding HP ground starter feed increased ADG and feed efficiency compared with LP groups during the preweaning and the overall periods. Moreover, weaning and final BW were higher in HP-fed calves than in LP-fed calves. Apparent digestibilities of acid detergent fiber (ADF), starch, and CP were greater in calves fed HP than in calves fed LP starter feed. The HP ground starter feed increased rumen propionate and ammonia concentrations. Wheat straw processing had no effect on intake and growth of calves but increased DM, ADF, and neutral detergent fiber digestibilities and decreased ruminal pH. Using processed wheat straw (PWS) mixed with starter feed tended to decrease rumination time and ruminal acetate concentration in calves. Final body barrel and withers height tended to be greater in calves fed PWS. Overall, the results indicated that HP content of ground starter feed (23.5%) could be recommended for Holstein calves. Furthermore, PWS inclusion in the ground starter diet increased fiber digestibility but had no effect on calf performance. Moreover, calves fed HP-PWS had greater ADG and final BW than other treatments.

Microstructure, Thermal Conductivity, and Flame Retardancy of Konjac Glucomannan Based Aerogels.

With abundant renewable resources and good biodegradability, bio-based aerogels are considered as promising insulating materials for replacing the conventional petroleum-based foam. In this study, konjac glucomannan (KGM)-based aerogels were prepared as thermal insulation materials via a convenient sol–gel and freeze-drying progress with different content of plant polysaccharides, proteins, and wheat straw. The morphology, thermal conductivity, and flame retardancy of KGM-based aerogels were determined. The KGM-based aerogels showed a uniform three-dimensional porous microstructure. The addition of wheat straw could significantly reduce the pore size of aerogels due to its special multi-cavity structure. KGM-based aerogels showed low densities (0.0234–0.0559 g/cm−3), low thermal conductivities (0.04573–0.05127 W/mK), low peak heat release rate (PHRR, 46.7–165.5 W/g), and low total heat release (THR, 5.7–16.2 kJ/g). Compared to the conventional expanded polystyrene (EPS) and polyurethane (PU) foam, the maximum limiting oxygen index (LOI) of KGM-based aerogels increased by 24.09% and 47.59%, the lowest PHRR decreased by 79.37% and 94.26%, and the lowest THR decreased by 76.54% and 89.25%, respectively. The results demonstrated that the KGM-based aerogels had better performance on flame retardancy than PU and EPS, indicating high potential applications as heat insulation in the green advanced engineering field.

Effect of bamboo biochar on reducing grain cadmium content in two contrasting wheat genotypes.

Wheat is the second most important food crop worldwide, which is prone to accumulate cadmium (Cd). Accumulation of Cd in wheat grains depends not only on wheat genotype, but also largely on the availability of soil Cd and its internal distribution. In this study, several experiments were used to achieve low-grain Cd content: a field trial for wheat genotype screening, a soil incubation experiment to test passivation effect of bamboo biochar on soil Cd, and a soil pot experiment to examine bamboo biochar effect on wheat grain accumulation. The results showed that of the 243 wheat cultivars tested, the variation range of grain Cd content was 0.365-1.243mg/kg, in a field with soil Cd of 3mg/kg. The application of bamboo biochar reduced soil Cd availability, among which 5.0% bamboo biochar treatment had the greatest effect. The content of available Cd in soil treated with 5.0% bamboo biochar decreased by 0.32mg/kg compared with the control in a 120-day incubation experiment. Effect of bamboo biochar (0, 0.1%, 1.0%, and 5.0%) on reducing grain Cd content in two wheat genotypes (Mianyou-1 and 1279-9) was investigated. The application of bamboo biochar decreased Cd uptake by plants, while distribution of Cd in different wheat plant parts was more controlled by the plant genetic characteristics. Compared with the control, Cd content in roots, straw, and grains was decreased by 34.06% (P < 0.05), 21.57%, and 23.33%, respectively, in low-grain Cd wheat cultivar 1279-9 by 5% bamboo biochar application. Overall, the combination of low-grain Cd accumulation wheat and bamboo biochar may be a feasible strategy to lessen grain Cd accumulation in Cd-contaminated soils.

Effects of bio-npk consortium on growth, yield and nutrient uptake by rice under clay loam textured soil

Field experiment was conducted to see the effects of bio-NPK consortium on growth, yield and nutrient uptake by rice during kharif season of 2018 at Research Station, Anand Agricultural University, Thasra. The experiment was laid out in a randomized block design, comprising of twelve treatment combinations of different levels of iron (Fe) and zinc (Zn) with or without bio-NPK consortium (Azotobacter sp., Azospirillim sp. and Bacillus sp.) with three replications. The soil of Thasra experimental field was clay loam texture, medium in organic carbon, available nitrogen (N) and phosphorus (P), high in available potassium (K) and medium in available Zn and Fe. Results revealed that application of RDF + 75% Zn + 75% Fe + Bio-NPK consortium (T12) recorded significantly higher yield and uptake of N, P and S by rice grain and straw. The Fe content in straw and Zn content in grain increased significantly with application of RDF + 100% Zn + 100% Fe + Bio-NPK consortium (T10). Significantly higher Fe and Zn uptake by grain and straw of rice was observed with application of RDF + 75% Zn + 75% Fe + Bio-NPK consortium (T12). Maximum Cu uptake by rice straw was recorded with application of RDF + 100% Zn + 100% Fe + Bio-NPK consortium (T10). The available N, P, K, S, Zn, Mn and Cu content in soil after harvest of rice failed to show any significant influence with different treatments. Significantly higher available Fe (7.10 mg kg-1) in soil after harvest of rice was found in treatment with RDF + 75% Zn + 75% Fe (T11). Maximum population of Azotobacter, Azospirillum, phosphate solubilizing bacteria and potassium mobilizing bacteria in soil was found in treatment T12 (RDF + 75% Zn + 75% Fe + Bio-NPK consortium) over control.

Short-term effect of rice straw application on soil fertility and rice yield

The study was conducted at the experimental field of the Department of Soil Science of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh during July to November 2015 in transplanted aman (T. aman) season to evaluate the influence of rice straw application on growth and yield of rice (BINA dhan7) and soil fertility. The experimentation was established following a randomized complete block design (RCBD) using 3 treatments (T1= Inorganic fertilizer dose as per STB, T2= rice straw + inorganic fertilizer as IPNS basis and T3= Farmer’s practice). Results of the experiment showed that application of rice straw along with inorganic fertilizers as IPNS basis did not produce any significant (p<0.05) variation in yield and yield regulating parameters of T. aman rice but ensured higher filled grains panicle-1 (96.68), 1000- grain weight (23.23g), straw (6.97 t/ha) and grain yield (6.32 t/ha) as compared to other treatments. Short term addition of rice straw in soil did not create any significant influence on post harvest soil nutrient status except K which was found high. Significantly highest N contents in grain and straw were observed in straw added plots, which further contributed to higher nutrient uptake by grain and straw.

Enhanced Degradation of Corn Straw for Methane Production Via a Novel Composite Fungal Agent

<b>Highlights</b> <list list-type=bullet><list-item> A novel composite fungal agent was used to pretreat straw. </list-item><list-item> Scanning electron microscopy showed that the lignocellulosic structure was obviously damaged by the composite fungal agent. </list-item></list> <list list-type=bullet><list-item> The methane yield per g of straw was 51.7% higher than that of the untreated group. </list-item><list-item> The T80 (time taken to reach 80% gas production) was shortened by 31.8%. </list-item></list> <b>Abstract</b>. In this study, the fungal agent consisting of Phanerochaete chrysosporium (Pc) and Trametes gallica (Tg) were studied. The effects pretreatment temperature, pretreatment time, fungi liquid addition, and fungi ratio had on the degradation of corn straw were studied. The anaerobic methane production performance of untreated and composite fungal agent treated corn straw was evaluated. To maximize the gas production, the response surface method was used to determine the optimal parameters of the pretreatment of straw by the composite fungal agent, The proportion of the fungi was Tg: Pc= 3:1, and the amount of fungi added was 6%. The pretreatment temperature was 28.5℃ and the pretreatment time was 11 d. The cellulose content in the corn straw pretreated by this condition was (29.6±1.4)%, the hemicellulose content was (22.0±1)%, the lignin content was (8.9±0.6)%, and the gas production after pretreatment was (232.9±4.8) mL/gstraw, the gas production was increased by 51.7% compared with the untreated control group, and the T80 (time taken to reach 80% gas production) was shortened by 31.8%. In addition, the degradation effect of composite fungal agent pretreatment under scanning electron microscope (SEM) was observed. The SEM showed that the bundle structure of cellulose was obviously damaged, indicating that the composite fungal agent had a significant effect on straw degradation.

Ruminant Feed Production and Nutritional Evaluation by Ensiling Rice Straw, Napier Leftover, and Rumen Content

Ruminant Feed Production and Nutritional Evaluation by Ensiling Rice Straw, Napier Leftover, and Rumen Content

A Model for Organic Matter of Fields Fertilized with Anaerobic Digestion Reactor Effluent

Soil fertility in agriculture is maintained by recalcitrant organic matter in manures and crop residues that are recycled to the fields. In some countries crop residues are burned in the field and in others these are collected and burned in furnaces as a source of renewable energy. These practices reduce the organic matter of the soils which is essential for their fertility. Anaerobic digestion installations convert manures and crop residues (mainly straw) into carbon dioxide, methane and other components. There remains a residue of recalcitrant organic material. The methane is is used as a source of renewable energy. The objective of this study is to determine the reduction in soil organic matter due to the anaerobic digestion of straw and cattle manure. The dynamics of the decay process of straw in the soil has been applied to the anaerobic digestion of these substrates. The decay of the organic material in the effluent of anaerobic digestion installations recycled to the fields has been modelled and compared to the decay of the substrates in the soil, without anaerobic digestion. The few field data on the effect of the effluent of anaerobic digestion reactor show no or little variation, compared to those when the substrates are directly applied to the fields. Around 45% of the energy content of straw and manures can be used as a source of renewable energy. The contribution to the soil organic matter of recycled effluent is 85% of that of the substrates directly applied to the soil.

Comparison of Pyrolysis Liquids from Continuous and Batch Biochar Production—Influence of Feedstock Evidenced by FTICR MS

Bio-oils from biomass pyrolysis can be a resource for upgrading to chemicals or fuels. Here, for the first time, we compare the composition of bio-oils produced from two feedstocks (wheat straw, softwood) in pyrolysis units of different mode of operation (continuous—rotary kiln vs. batch) using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) in different ionization modes (APPI (+), ESI (+/−)). Our results demonstrate that the pyrolysis unit design had only a minor influence on the composition of bio-oils produced from low-mineral containing wood biomass. Yet, the wheat straw-derived bio-oil produced in the continuous unit comprised lower molecular weight compounds with fewer oxygen-containing functional groups and lower O/C and H/C ratios, compared to bio-oils from batch pyrolysis. Longer residence time of vapours in the heated zone in the rotary kiln and a higher mineral content in wheat straw resulted in increased catalytically-mediated secondary reactions that favoured further bio-oil decomposition. This work shows for the first time that it is possible to produce distinct bio-oils without the need for external catalyst addition, by matching reactor type/design and feedstock.

Effects of Two Types of Straw Biochar on the Mineralization of Soil Organic Carbon in Farmland

To investigate the effects of biochar on soil carbon composition and transformation, the effects of 1%, 2%, and 5% mass ratios of banana and cassava straw biochar on carbon dioxide release, total organic carbon (TOC), soluble organic carbon (SOC), and enzyme activity in soil were studied in incubation experiments at a constant temperature in the laboratory. The results showed that the cumulative CO2 emissions from cassava straw were 15.82 (1% addition ratio) and 28.14 μg·kg−1 (2%), which were lower than those from banana straw, i.e., 46.77 (1%) and 59.26 μg·kg−1 (2%). After culture, the total organic carbon contents of cassava straw were 8.55 (5%), 5.27 (2%), and 3.98 μg·kg−1 (1%), which were higher than those of banana straw, i.e., 6.31 (5%), 4.23 (2%), and 3.16 μg·kg−1 (1%). The organic carbon mineralization rate in each treatment showed a trend of increasing first, then decreasing, and finally stabilizing. There was a very significant positive correlation between catalase and urease activity in soil with cassava straw biochar and between catalase activity and SOC mineralization with banana straw biochar. It plays an important role in the transformation and decomposition of organic carbon. These results show that the application of biomass carbon can significantly improve the organic carbon content and enzyme activity of farmland soil, increase the cumulative mineralization amount and mineralization rate of SOC, and thus increase the carbon sequestration capacity of soil.

Influence of long term INM practices on the distribution of aluminium fractions in Acidic Inceptisol of North Eastern Himalaya Range and their relationship with NPK content in rice (Oryza sativa)

A long-term field experiment was commenced in 2006 with rice as a test crop under long-term integrated nutrient management (INM) practices at Instructional-cum-Research (ICR) farm of the Assam Agricultural University, Assam to study the distribution of aluminium (Al) fractions and their relationship with NPK content in different parts of rice plant under acidic Inceptisol. Results indicated that exchangeable Al and strongly organically bound and interlayer Al fractions effectively decreased whileweakly organically bound Al, amorphous Al and free Al fractions increased under integrated use of enriched compost @ 2 t/ha with 25% recommended doses of NP + 100% K over rest of the treatments. In rice, the integrated use of enriched compost @ 2 t/ha with 25% recommended doses of NP + 100% K showed significant increment in N and P content in grain, husk and straw over rest of the treatments. The K content in grain (0.36%), husk (0.37%) and straw (2.03%) was also found to be highest under application of 25% recommended doses of NP + enriched compost @ 2 t/ha + 100% K as compared to other treatments. There was a highly significant negative correlation was found between exchangeable Al and strongly organically bound and interlayer Al with N, P and K content of rice. Thus, integrated use of enriched compost with reduced dose of recommended nitrogen and phosphorus of rice reduced the toxic Al fractions in an acid soil which led to enhanced N, P and K content in rice grain, husk and straw.

Olive agroforestry can improve land productivity even under low water availability in the South Mediterranean

Agroforestry systems can be an effective means of stabilizing or even enhancing crop yields under climate change. Although trees compete with crops for soil resources in agroforestry,they can also improve crops' growing conditions, especially, by providing shade under drought. They can promote higher crop yields and higher harvest quality in the drylands. However, the beneficial effect of tree shade may depend on the seasonal pattern of rainfall, which determines the compensation between yield components. In this study, we evaluated two annual crops (durum wheat and faba bean) in olive agroforestry in northern Morocco. We manipulated water supply in a field experiment to span the high inter-annual rainfall variability at the site and tested whether olive trees reduce or improve crop yields. We assessed the effect of water addition on crop growth, yield components, and final yields and estimated the land equivalent ratio of olive agroforestry. Agroforestry limited crop growth and yield whatever the water regime. The magnitude of grain yield reduction was around 50 % for both crops in 2018, probably due to shade. The number of grains per unit area was the most impacted yield component in both 2018 and 2019. In contrast, water addition only had limited effects on faba bean yield, although it enhanced wheat grain yield by 11 % and the number of wheat spikes by 13 %. Agroforestry improved individual grain weight by 39 % for wheat and 17 % for faba bean, and enhanced the protein content of wheat grains and straw by 4 % and 9 %. However, improvements in grain weight and in protein content were not sufficient to compensate for yield loss due to shade. Despite lower crop yields, we show that agroforestry systems are still more land productive than sole crops and trees, even under arid conditions. We show how changing water supply may impact the performance of olive agroforestry in a drier future.