Wheat Pea Research Articles

Nitrogen use in spring wheat affected by crop diversification, management, and tillage

AbstractDryland wheat production potential in the northern Great Plains (NGP) often is limited by N availability affected by various management practices. A 4‐yr study was conducted in northeast Montana to relate spring wheat (Triticum aestivum L.) productivity and N utilization to management system (conventional and ecological), tillage (till and no‐till), and four crop rotations (continuous spring wheat, spring wheat–pea [Pisum sativum L.], spring wheat–hay barley [Hordeum vulgare L.]–pea, and spring wheat–hay barley–corn [Zea mays L.]–pea). Ecological management included greater seeding rates, delayed planting dates, banded N fertilizer, and increased stubble height compared with conventional management with standard seeding rates and planting dates, short stubble height, and broadcast N fertilizer. Continuous spring wheat showed the lowest grain yield, with the least efficient utilization of N compared with 2‐, 3‐, and 4‐yr rotations. Mineral nitrogen use efficiency was 37% lower for continuous wheat than for other rotations. Increasing the complexity of crop rotation had little impact on wheat production or N relationships. The delayed planting date associated with ecological management of spring wheat contributed to 33% less efficient use of N compared with an early planting date with conventional management. Overall, results indicated that crop rotation and management system often affected N relationships with wheat production, whereas the effects of tillage differed with year. Differences in yield and N use of spring wheat varied among years, underscoring the need to refine management systems given the highly variable precipitation patterns typical of the NGP.

Dissection of the Contributing Factors to the Variable Response of Crop Yield to Surface Applied Lime in Australia

Modern agricultural farming systems acidify the soil profile due to application of fertilisers with acidifying properties. In most parts of Australia, lime has been used to improve agricultural soil conditions and restore its productive potential. The observed response of crop yield to applied lime often varies with soil type, acidity profile and seasonal conditions, so it is difficult to specify the expected yield response in a given situation. We conducted a meta-analysis of 86 agricultural field trials from Western Australia (WA), New South Wales (NSW) and Victoria (VIC) where various rates of lime had been applied to the soil surface and crop yield (wheat, barley, canola, lupin or field pea) measured for a number of years after the initial application. Information from the meta-analysis was then paired with output from a crop simulation model, where the water-limited yield potential was estimated for both a neutral and acidified soil profile. The average increase in yield to applied lime across all locations and crops was 12%, but the response ranged from 0 to 185%. A trend was observed, where sites with topsoil pH (CaCl2) < 5 and subsoil pH < 4.5 had the greater benefit to liming. Soil type had little effect on the percentage yield increase. Overall, responses to applied lime were most likely when the yield of the trial site was at 50% of water-limited yield potential (or less), the quantity of lime applied was greater than 2.5 t ha−1 and the time since lime had been applied was greater than three years (with the maximum response occurring from four and sometimes up to eight years after liming). Therefore, soil pH measurements, combined with an assessment of actual yield relative to potential yield, provide the best guide to the response to surface applied lime and this response is likely to take more than four years to be realised.

Impacts of the Winter Pea Crop (Instead of Rapeseed) on Soil Microbial Communities, Nitrogen Balance and Wheat Yield

Due to legume-based systems improving several aspects of soil fertility, the diversification of agrosystems using legumes in crop succession is gaining increasing interest. The benefits of legumes aroused the interest of farmers in the association of the Economic and Environmental Interest Group (EEIG), who introduced the idea of using the winter pea instead of rapeseed in their crop succession. The aim of this study is to evaluate the effects of the winter pea compared to those of rapeseed, as a head crop of the rotation, on soil microbial communities, enzyme activities, nitrogen (N) balance and yields. The field experiment involved two farmer plots that were selected within the EEIG. In each plot, two crop successions, including winter pea–wheat and rapeseed–wheat with fertilized and unfertilized strips, were examined for two years. Three times a year, under the wheat crop, composite soil samples were collected at depths of 0–20 cm, for microbial abundance and enzyme activity analyses, and twice a year at a depth of 0–60 cm, for the measuring of the mineral N. The results showed that the rapeseed–wheat succession maintained or enhanced soil bacterial and fungal biomasses and their enzyme activities. The winter pea–wheat succession enriched the soil’s mineral N content more consistently than the rapeseed–wheat succession. The mineral N enhancement’s effect was maintained under the wheat crop. Overall, the impact of the winter pea was positive on the soil’s N dynamics, but wheat yields were equivalent regardless of the previous crop (winter pea or rapeseed with and without fertilization). In the Normandy region, as rapeseed requires a large amount of N fertilizer and pesticide to maintain the yield and quality of crop products, it is suitable to favor the introduction of the winter pea as the head crop of the rotation, which indirectly allows for a reduction in the costs of input production and use, the working time of farmers and environmental pollution.

Barriers and Levers to Developing Wheat–Pea Intercropping in Europe: A Review

Beyond the ecosystem benefits of diversification through wheat–pea intercropping, this review analyzes the barriers and levers to its adoption and diffusion. The present review shows that structuring the value chain around the products of this innovative cropping system faces a set of technical (i.e., varietal selection, phytosanitary issue control, crop management sequence, collection management, and storage), economic (i.e., cost, price, market opportunities, and contracting), and public policy (i.e., subsidies for ecosystem services provided by intercropping) obstacles that contribute to its slow adoption and dissemination in Europe. However, the value chain resulting from the wheat–pea intercropping system has levers to be exploited at all levels, particularly in terms of its competitive advantages, ecosystem benefits, and superior product quality. The results of this review help to identify priorities that actors of the value chain can address to better focus their efforts on significant problems and solutions that can accelerate the adoption and dissemination of this agroecological system.

Assessment of bio-inoculants-mediated nutrient management in terms of productivity, profitability and nutrient harvest index of pigeon pea–wheat cropping system in India

Imbalanced and indiscriminate use of chemical fertilizers has been adversely influencing the quality of soil, environment, biodiversity and nutrient status in soil. Conjoint application of bio-inoculants (BI) with organic or inorganic sources of nutrients tweaks nutrient synchrony in soil and improves plant nutrition. With this backdrop an experiment was conducted at Indian Agricultural Research Institute, New Delhi during 2016–2018. The objectives were to identify the suitable combinations of BI-mediated nutrient sources for higher productivity and profitability in pigeon pea–wheat cropping system (PWCS). The nine pigeon pea treatments; four sole applications viz., recommended dose of fertilizers (RDF), vermicompost (VC), farm yard manure (FYM), leaf compost (LC) and four conjoint applications viz., RDF + BI, VC + BI, FYM + BI and LC + BI and one control were replicated thrice under randomized block design (RBD). However, in succeeding wheat, each of the treatments applied to pigeon pea was further allocated to two levels (50% and 100%) in factorial RBD. Findings exhibit that FYM + BI could result into higher equivalent-system grain productivity (10.4 and 10.8 t ha−1 during 1st and 2nd year, respectively) of PWCS. However, profitability parameters of PWCS were higher with the RDF + BI. Uptake of nutrients (NPK) was significantly higher with FYM + BI in pigeon pea and RDF + BI in wheat. Nutrient harvest index (NHI) did not vary significantly in both the crops. Conclusively, bio-inoculation is more productive and beneficial in general, while, over the various combinations, recommendation of FYM + BI combination could be more productive and sustainable.

Reducing nitrous oxide emissions and optimizing nitrogen-use efficiency in dryland crop rotations with different nitrogen rates

Recent interests in improving agricultural production while minimizing environmental footprints emphasized the need for research on management strategies that reduce nitrous oxide (N2O) emissions and increase nitrogen-use efficiency (NUE) of cropping systems. This study aimed to evaluate N2O emissions, annualized crop grain yield, emission factor, and yield-scaled- and NUE-scaled N2O emissions under continuous spring wheat (Triticum aestivum L.) (CW) and spring wheat–pea (Pisum sativum L.) (WP) rotations with four N fertilization rates (0, 50, 100, and 150 kg N ha−1). The N2O fluxes peaked immediately after N fertilization, intense precipitation, and snowmelt, which accounted for 75–85% of the total annual flux. Cumulative N2O flux usually increased with increased N fertilization rate in all crop rotations and years. Annualized crop yield and NUE were greater in WP than CW for 0 kg N ha−1 in all years, but the trend reversed with 100 kg N ha−1 in 2013 and 2015. Crop yield maximized at 100 kg N ha−1, but NUE declined linearly with increased N fertilization rate in all crop rotations and years. As N fertilization rate increased, N fertilizer-scaled N2O flux decreased, but NUE-scaled N2O flux increased non-linearly in all years, regardless of crop rotations. The yield-scaled N2O flux decreased from 0 to 50 kg N ha−1 and then increased with increased N fertilization rate. Because of non-significant difference of N2O fluxes between 50 and 100 kg N ha−1, but increased crop yield, N2O emissions can be minimized while dryland crop yields and NUE can be optimized with 100 kg N ha−1, regardless of crop rotations.

Changes in soil chemical properties and crop yields with long‐term cropping system and nitrogen fertilization

AbstractInformation is needed on the long‐term impact of cropping system and N fertilization on dryland soil health and crop yields. We studied the 13‐yr effect of cropping system and N fertilization rate on soil chemical properties at the 0‐ to 60‐cm depth and related them to annualized crop yield in the northern Great Plains. Cropping systems were conventional tillage barley (Hordeum vulgare L.)/spring wheat (Triticum aestivum L)–fallow (CTB/WF), no‐tillage barley/spring wheat–fallow (NTB/WF), no‐tillage barley/spring wheat–pea (Pisum sativum L) (NTB/WP), and no‐tillage continuous barley/spring wheat (NTCB/W). Nitrogen fertilization rates were 0, 40, 80, and 120 kg N ha−1 to barley planted from 2006 to 2011 and 0, 50, 100, and 150 kg N ha−1 to spring wheat planted from 2012 to 2018. At 0 to 5 cm, soil pH and CEC were greater with NTB/WP than NTCB/W and CTB/WF, and soil organic matter (SOM) and Olsen‐P were greater with NTCB/W than CTB/WF. Increased N rate reduced soil pH, K, Ca, Mg, and CEC at most soil depths. Annualized crop yield was greater with NTCB/W and NTB/WP than NTB/WF and CTB/WF and maximized at 80–100 kg N ha−1. Most soil chemical properties induced by N fertilization were negatively correlated, but Mg concentration at 30–60 cm induced by cropping system was positively correlated with annualized crop yield. No‐till barley/spring wheat–pea rotation with 80–100 kg N ha−1 can sustain dryland soil chemical properties and barley and spring wheat yields in the northern Great Plains.

Influence of row spacing and seeding rate on crop yields cultivated by “No-Till” technology in Kulunda steppe (Altai Region)

The long-term field experience has been carried out in the LLC Farm Enterprise “Partner”, Mikhailovsky District of the Altai Region, one of the basic sites of the “Kulunda” project. The field experience was founded in 2013, implemented over the next four years in a similar way; the alternation of crops was carried out in accordance to the crop rotation. In total, there were four sets of experiments in eight variants in triple number of replications. There were four variants of row spacing implemented: 25.0 cm, 33.3 cm, 37.5 cm, and 50.0 cm. We also used two seeding rates for every crop: spring wheat - 75 and 120 kg/ha; rapeseed – 2 and 4 kg/ha; peas – 140 and 180 kg/ha. The sowing was made with an expimental grain seeder “Cornor-DMC” with chisel-shaped copying coulters, the “Amazone” company production. Combine harvesters “Lexion” (peas and rapeseed) and “Sampo” (wheat) carried out harvesting in August-September. As an object of research, the technological process of cultivation of agricultural crops in the crop rotation of spring wheat–pea–spring wheat–rape was considered. The influence of the row spacing and the seeding rate on the yield was evaluated. An increase in row spacing from 25 cm to 50 cm leads to an almost linear decrease in the yield of crops. The increasing of the seeding rate in the studied limits leads to the yield enhancement. The obtained data will allow substantiating the rational row spacing, design of the sowing complex and seeding rate. This is extremely important for introducing the “No-Till” technology in the arid steppe of the Altai Region.

Micronutrient Concentrations in Soil and Wheat Decline by Long-Term Tillage and Winter Wheat–Pea Rotation

Tillage plays a major role in nutrient dynamics under dryland cropping systems, but there remains uncertainty regarding the long-term impacts of tillage on nutrient availability. The objective of this study was to examine the influence of tillage intensity and timing on micronutrient concentration of soils and winter wheat (Triticum aestivum L.) under dryland winter wheat–pea (Pisum sativum L.) or WW-P rotation. The treatments included moldboard tillage in fall (FT) and spring (ST), disk/chisel tillage (DT), and no-tillage (NT). The concentrations of Mehlich III extractable boron, manganese, zinc, copper, and iron in soil were unaffected by the tillage methods; however, a significant decline in extractable zinc in the top 10 cm soil was observed compared to an adjacent undisturbed grass pasture (GP) (NT: 2.3 mg kg−1 vs. GP: 6.0 mg kg−1). In the upper 10 cm soil surface, NT (123 mg kg−1) maintained the extractable manganese concentration with GP (175 mg kg−1) whereas FT (97 mg kg−1), ST (92 mg kg−1), and DT (113 mg kg−1) had lower manganese than GP. Soil pH declined in the upper 10 cm under NT more than in the rest of the WW-P treatments. The results suggest NT can play a vital role in sustaining micronutrient availability due to decreased soil pH and the greater amount of organic matter within the surface soil of NT compared to other tillage methods.

Clinical case report on nutritional dystrophy in goats at S. A. Quadary Veterinary Teaching Hospital, CVASU, Chittagong

Background: Nutritional fibrous osteodystrophy may be developed due to dietary deficiency of calcium or dietary excess of phosphorus. Fibrous osteodystrophy (FOD) provokes hyperostotic distortion of cancellous bones, conjunctive tissue proliferation, and poor mineralization of bone. The objectives of this study were to report the clinical characteristics and therapeutic management of FOD in goats. Materials and methods: Four out of 8 Jamnapari goats developed fibrous osteodystrophy in a small scale intensive household farm in Chittagong. The age range of the affected goats was 4-5 months. The feeding history of goats was primarily wheat bran, gram and pea husk. Blood sample from all affected and non-affected animals and feed sample from household farm were collected for laboratory analysis. Fibrous Osteo-dystrophy was primarily diagnosed by observing clinical signs of mandibular and maxillary enlargement, pain on pressure at the enlarged bone, protruded tongue and dyspnea which was then confirmed by high level of phosphorus in serum evaluation. Results: The calcium and phosphorus contents in the sampled gram, pea husk and bran were 0.5%, 0.3% and 0.5%, and 0.71%, 0.49% and 0.61%, respectively. Most of the affected animals had increased serum levels of phosphorus, glucose and alkaline phosphatase and decreased level of calcium. Based on the clinical findings and the laboratory report, the cases were diagnosed as fibrous osteodystrophy due to nutritional imbalance in diet. The owner was advised strictly to stop providing any bran to animals (affected and healthy). Affected animals were additionally treated with calcium preparation vitamin ADE, ketoprofen, protein, and penicillin-streptomycin combination. Conclusion: Treatment of fibrous osteodystrophy required a long time recovery along with balanced ration. A combined therapy of calcium and vitamin D and protein preparation is effective for treatment along with adequate green grass and balanced rations.

Assessing the performance of pea and lentil at different seeding densities as trap crops for the management of wireworms in spring wheat

AbstractWireworms, the larvae of click beetles (Elateridae), are difficult to manage due to their habitats and behaviour. Wireworms pose a major threat to the wheat crop in the north‐western USA. Seed treatment with neonicotinoids, biological control management and some cultural controls are recommended to manage these pests. Trap cropping is an emerging way to manage wireworms. In strawberry and potato crops, trap cropping has been found effective at attracting wireworms away from the principal crop. An earlier study in the Golden Triangle area of Montana found that pea and lentil could be effective trap crops for managing wireworms in spring wheat. In the present study, experiments were conducted at two locations. The effectiveness of peas and lentils as trap crops with wheat at different seeding densities was assessed [pea at 0, 4, 8, 16 seeds/sq.ft. or 0, 43, 86, 172 seeds/sq.m.; lentil at 0, 6, 12, 18 OR 0, 65, 130, 194 seeds/sq.m.; both with wheat at 0, 11, 22, or 28 seeds/sq.ft. or 0, 120, 230, 300 seeds/sq.m.] in a randomized design where all three crops were intercropped. Both trap crops were found to be effective in protecting wheat at standard seeding rates of 8 seeds/sq.ft. for pea and 12 seeds/sq.ft. for lentils. At these seeding rates, higher numbers of wireworms were found to be attracted to the trap crop, resulting in higher yield (7%–10%) of the associated spring wheat plant stands at 22 seeds/sq.ft. To develop an effective trap crop strategy, the pea–wheat and lentil–wheat spatial patterns that are possible need to be assessed in further field trials. Proper design and evaluation of the cost–benefit ratio of pea and lentil as trap crops are likely to produce good results for wheat crops in Montana.

Evaluation of bacterial and fungal diversity in a long-term spring wheat – field pea rotation field under different tillage practices

Soil management practices have the potential to modify the diversity and function of microbes in agricultural fields. The aim of this study was to investigate bacterial and fungal diversity in a 15 yr wheat–pea rotation tillage experiment. The treatments included conventional tillage with stubble removed, no-till with stubble removed, no-till with stubble retained (NTS), and conventional tillage with stubble incorporated. Illumina high-throughput sequencing platform was employed to sequence bacteria 16S rRNA (V3V4) and fungi internal transcribed spacer (ITS2) region genes in 0–10 cm and 10–30 cm of soil sampled. The dominant bacterial and fungal phyla identified at 97% similarity cutoff across both depths of treatments were Proteobacteria (26.3%), Actinobacteria (25.1%), Acidobacteria (15.0%), Gemmatimonadetes (8.8%), Ascomycota (85.8%), and Basidiomycota (8.0%). NTS had significantly (p < 0.05) higher microbial diversity indices, total organic carbon, soil microbial biomass carbon and nitrogen, NO3-N, and NH4-N at 0–10 cm depth. Tillage and stubble effects had a significant correlation with some phyla such as Proteobacteria, Actinobacteria, Gemmatimonadetes, JL-ETNP-Z39, Nitrospirae, Chloroflexi, Firmicutes, and other identified and unidentified minor microbial phyla. No-till and residue retention practices influenced fungal and bacterial species diversity through improved soil chemical properties, which have potential to affect the habitat and activity of soil microbes. Therefore, no-till and stubble retention could improve soil quality and promote sustainable agriculture in the rainfed Loess Plateau.

Soil Carbon, Nitrogen, pH, and Crop Yields in Winter Wheat–Spring Pea Systems

Core Ideas Under wheat–pea, reduced tillage increased SOC, TN, and pea yields over fall plowing. No‐till decreased surface soil pH and wheat yields relative to fall plowing. Spring plowing minimized surface soil acidification, increased crop yield, and maintained SOC and TN. Data from an ongoing winter wheat (Triticum aestivum L.)–spring pea (Pisum sativum L.) long‐term experiment on a Walla‐Walla silt loam (coarse‐silty, mixed, mesic Typic Haploxeroll) in eastern Oregon was used to evaluate the effects of four tillage systems [fall plow (FP), spring plow (SP), disk tillage and chisel plow (DT/CP), and no‐till (NT)] on soil pH, bulk density, soil organic carbon (SOC), total nitrogen (TN), and grain yields. Among tillage types, FP produced the lowest pea yields in 4 out of 6 crop‐years, whereas NT produced the lowest wheat yields during dry and hot crop‐years. Both NT and DT/CP had lower soil pH than FP and SP in the surface 10 cm. Soil organic C and TN were higher under NT and DT/CP than under FP and SP in the surface 10 cm. However, SP increased SOC and TN over NT at soil depth of 10 to 20 cm. Under wheat–pea, NT and DT/CP will increase SOC, TN, and pea yields but may reduce surface soil pH and decrease wheat yields relative to conventional FP. Spring plow has the potential to minimize surface soil acidification, increase crop yield, and maintain SOC and TN in wheat‐pea systems.

Polyphenol contents and antioxidants activities of biscuits produced from ginger-enriched pigeon pea-wheat composite flour blends

This study investigated the phenolic content and antioxidant activities of biscuits produced from pigeon pea–wheat flour. Biscuits were produced by substituting wheat flour (WF) with pigeon pea flour (PP) in proportions of 100:0 (WF), 75:25 (25-PP), 50:50 (50-PP), 25:75 (75-PP), and 0:100 (100-PP) and fortified with ginger (4.5%). Aqueous extracts of flour and biscuit blends were prepared by dissolving each sample in distilled water (1:100 w/v), after which clear supernatant was obtained prior to analyses of phenolic content and antioxidant activities. The result revealed that the flour blends had higher total phenol and flavonoid contents as well as higher antioxidant activities than the biscuit blends. However, 100-PP flour and 100-PP biscuit blends had the highest phenolic content and antioxidant activities in comparison with their respective blends. This result suggests that the pigeon pea–wheat flour and biscuit blends could serve as cheap functional foods. Practical applications Pigeon pea is a highly nutritious legume seed but its consumption is limited due to the presence of antinutritional factors and its hard-to-cook nature. The composite biscuits produced from pigeon pea–wheat flour are rich in polyphenols and have high antioxidant activities as well as lower antinutrient contents. Therefore, these could serve as functional food. However, to encourage the consumption of the underutilized pigeon pea, the composite flour as well as the composite biscuits could be produced on a large scale as cheap, adequate, and available functional food. This will also encourage the overall cultivation and consumption of the food crop.

Nitrogen balance in dryland agroecosystem in response to tillage, crop rotation, and cultural practice

Accounting of N inputs and outputs and N retention in the soil provides N balance that measures agroecosystem performance and environmental sustainability. Because of the complexity of measurements of some N inputs and outputs, studies on N balance in long-term experiments are scanty. We examined the effect of 8 years of tillage, crop rotation, and cultural practice on N balance based on N inputs and outputs and soil N sequestration rate under dryland cropping systems in the northern Great Plains, USA. Tillage systems were no-tillage (NT) and conventional tillage (CT) and crop rotations were continuous spring wheat (Triticum aestivum L.) (CW), spring wheat–pea (Pisum sativum L.) (W–P), spring wheat–barley (Hordeum vulgaris L.) hay–pea (W–B–P), and spring wheat–barley hay–corn (Zea mays L.)–pea (W–B–C–P). Cultural practices were traditional (conventional seed rates and plant spacing, conventional planting date, broadcast N fertilization, and reduced stubble height) and improved (variable seed rates and plant spacing, delayed planting, banded N fertilization, and increased stubble height). Total N input due to N fertilization, pea N fixation, atmospheric N deposition, crop seed N, and nonsymbiotic N fixation was greater with W–B–C–P than CW, regardless of tillage and cultural practices. Total N output due to aboveground biomass N removal and N losses due to denitrification, volatilization, plant senescence, N leaching, gaseous N (NOx) emissions, and surface runoff were not different among treatments. Nitrogen sequestration rate at 0–20 cm from 2004 to 2011 varied from 29 kg N ha−1 year−1 in CT with W–P to 89 kg N ha−1 year−1 in NT with W–P. Nitrogen balance varied from − 39 kg N ha−1 year−1 in NT with CW and the improved practice to 41 kg N ha−1 year−1 in CT with W–P and the traditional practice. Because of legume N fixation and increased soil N sequestration rate, diversified crop rotations reduced external N inputs and increased aboveground biomass N removal, N flow, and N balance compared with monocropping, especially in the CT system. As a result, diversified legume–nonlegume crop rotation not only reduced the cost of N fertilization by reducing N fertilization rate, but also can be productive by increasing N uptake and N surplus and environmentally sustainable by reducing N losses compared with nonlegume monocropping, regardless of cultural practices in dryland agroecosystems.

Potential Benefit and Risk of Fluridone as a Fall Germination Stimulant in Western Canada

Herbicide resistance has increased the need for novel weed control strategies. Fluridone has herbicidal as well as potential germination stimulant activity. The objectives of this study were to evaluate fluridone as a fall-applied germination stimulant for weed control and to assess rotational crop tolerance. Fall-applied fluridone was compared with a nontreated control in areas established with false cleavers, volunteer canola, and wild oat at Lacombe, AB, in 2014–2015 and 2015–2016, and at St Albert, AB, in 2015–2016. In the fall, there was a trend for weed densities to be higher in fluridone treatments than in untreated controls across site-years. The stimulatory effect of fluridone on weed germination was not statistically significant in fall assessments, while the weed control effect was significant in 33% of spring assessments. While fluridone reduced weed biomass for some site-years, it also reduced canola crop emergence and biomass at St Albert in 2015–2016, and caused injury symptoms on wheat and field pea. Risk of carryover to subsequent crops outweighed the benefits of using fluridone in the fall to stimulate weed germination in this study.

THE ORIENTATION OF BIOLOGICAL NITROGEN TRANSFORMATION PROCESSES IN SOIL UNDER THE ORGANIC PRODUCTION OF AGRICULTURAL PRODUCTS

The paper covers the study of direct impact and after-effect of 40 t/ha of cattle manure on theorientation of nitrogen fixation and biological denitrification processes in the root zone of potatoes,spring barley, pea, and winter wheat plants in rotation in a stationary field experiments on leachedblack soil. Application of manure had significantly increased the nitrogen fixation activity, whilepromoting a high level of N2O emission. The use of microbial preparations for pre-seeding bacterization of seeds optimizes the course of biological nitrogen transformation process — through theenhancement of nitrogen fixation activity and reduction of gaseous nitrogen losses (with the exception of Biogran use on potatoes in the year of manure application). Introduction with manure of alarge number of microorganisms to the soil offsets the positive effect of biopreparations use. Yieldrecords and estimation of grain output per hectare within the crop rotation cycle indicates the practicability of combined application of manure and microbial preparations (excluding the year of direct effect of organic fertilizer) in organic agriculture.

A push–pull strategy to control aphids combines intercropping with semiochemical releases

Even if insect pest populations can be reduced by increasing plant diversity through intercropping, natural enemies are not always favored in such systems. Alternatively, semiochemical substances have been tested to enhance biological control, with inconsistent results. Combining both strategies can be an interesting way to maximize pest control. In this work, a 2-year setup involving wheat–pea strip intercropping combined with the release of E-β-farnesene (EBF) or methyl salicylate (MeSA) was tested as a push–pull strategy to simultaneously repel aphids and attract beneficials. Two types of slow-release formulation (i.e., oil and alginate beads) containing EBF or MeSA were deployed with the intercropping. The abundance of aphids was significantly decreased, while hoverfly larvae and mummified aphids increased on both pea plants and wheat tillers by the release of oil-formulated EBF and MeSA. The proportion parasitism of the aphid-parasitism rate [mummies/(aphids + mummies)] was also increased by treating both crops in both years. Releasing EBF through oil rather than alginate beads proved significantly better for attracting natural enemies and reducing aphids. Aphids were negatively correlated with the density of hoverflies (both adults and larvae) and numbers of mummies. All these results showed that combining intercropping with the release of EBF or MeSA formulated in oil can significantly reduce aphid density and attract their natural enemies. Therefore, the combination of both strategies could help farmers reduce the use of insecticides.

Conservation Tillage Practices Optimizes Root Distribution and Straw Yield of Spring Wheat and Field Pea in Dry Areas

The objective of this study was to evaluate the effect of conventional tillage with straw removed (T), no tillage with straw removed (NT), no tillage with straw retained on the soil surface (NTS) and conventional tillage with straw incorporated (TS) on soil moisture, root growth and straw yield under rain-fed conditions. Findings of this research show that NTS and to a lesser extent, TS decreased soil bulk density in the 0-10 cm soil depth by approximately 3.35% and 2.75% compared to T and NT in spring wheat and field pea plots respectively. No tillage with straw retained (NTS) had greater soil moisture content (0-30 cm) at jointing, anthesis and milking stages compared with NT and T treatments with average 18.57% and 29.67% increase (P < 0.05) in spring wheat and field pea respectively. Compared with T and NT, root length, root surface area, root diameter and root volume at 0-50 cm soil depth under straw treated soils, especially with no tillage were significantly increased. Root length, surface area and root diameter in the 0-80 cm differed among the treatments in the order of NTS > TS > NT > T at all the sampling stages in both crops. No tillage with straw retention had the greatest straw yield of 4897 kg ha-1 in spring wheat and 2759 kg ha-1 in field pea, representing a significant increase of 20.61% and 22.74% compared to NT and T respectively. These results suggest that NTS could enhance spring wheat and field pea yield and water uptake via stimulating root growth, and therefore a practical way to improve crop productivity.

PGR-Clim: Climate Atlas of Genetic Resources of Five Crops

PGR-Clim is a web-based tool that provides an easy interface to access climate change (temperature and rainfall) atlases relevant to plant genetic resources management. The online tool combines climatic data with information on germplasm collection sites of five crops (sorghum, pearl millet, wheat, chickpea and pigeon pea) to predict future (2020 and 2050) climatic situations at germplasm occurrence sites. The tool allows users to choose a crop and visualize how climate is predicted to change over time and stimulate them to assess impacts and plan for measures of mitigation and adaptation.