Winter Pea Research Articles

The LTAR Cropland Common Experiment at R. J. Cook Agronomy Farm.

Dryland agriculture in the Inland Pacific Northwest is challenged in part by rising input costs for seed, fertilizer, and agrichemicals; threats to water quality and soil health, including soil erosion, organic matter decline, acidification, compaction, and nutrient imbalances; lack of cropping system diversity; herbicide resistance; and air quality concerns from atmospheric emissions of particulate matter and greenhouse gases. Technological advances such as rapid data acquisition, artificial intelligence, cloud computing, and robotics have helped fuel innovation and discovery but have also further complicated agricultural decision-making and research. Meeting these challenges has promoted interest in (1) supporting long-term research that enables assessment of ecosystem service trade-offs and advances sustainable and regenerative approaches to agriculture, and (2) developing coproduction research approaches that actively engage decision-makers and accelerate innovation. The R. J. Cook Agronomy Farm (CAF) Long-Term Agroecosystem Research (LTAR) site established a cropping systems experiment in 2017 that contrasts prevailing (PRV) and alternative (ALT) practices at field scales over a proposed 30-year time frame. The experimental site is on the Washington State University CAF near Pullman, WA. Cropping practices include a wheat-based cropping system with wheat (Triticum aestivum L.), canola (Brassica napus, variety napus), chickpea (Cicer arietinum), and winter pea (Pisum sativum), with winter wheat produced every third year under the ALT practices of continuous no-tillage and precision applied N, compared to the PRV practice of reduced tillage (RT) and uniformly applied agrichemicals. Biophysical measurements are made at georeferenced locations that capture field-scale spatial variability at temporal intervals that follow approved methods for each agronomic and environmental metric. Research to date is assessing spatial and temporal variations in cropping system performance (e.g., crop yield, soil health, and water and air quality) for ALT versus PRV and associated tradeoffs. Future research will explore a coproduction approach with the intent of advancing discovery, innovation, and impact through collaborative stakeholder-researcher partnerships that direct and implement research priorities.

Effects of Cover Crop on Selected Abiotic and Biotic Soil Health Indicators

Current cropping systems, like cover cropping, aim to improve soil health and crop productivity, with the former a more sustainable route to the latter. This can be done by evaluating the influence of cover crops (CCs) on soil health indicators, both abiotic and biotic, as is the objective of this study. Several CCs (crimson clover [Trifolium incarnatum L.], oats [Avena sativa], hairy vetch [Vicia villosa Roth.], winter wheat [Triticum aestivum L.], winter peas [Lathyrus hirsutus L.], flax [Linum usitassimum L.], triticale [Triticale hexaploide Lart.], cereal rye [Secale cereale], and barley [Hordeum vulgare L.]) were used across two research sites, set up using a completely randomized design with two levels of CCs (CC vs no cover crop [NC]) and three replicates during 2023. Soil samples were collected at 0-10, 10-20, and 20-30 cm depths and analyzed for soil physico-chemical properties and microbial biomass and composition. Results showed significantly lower bulk density values, greater water content (at 0 kPa soil water matric potential), greater volume-specific heat capacity (at 0 and -33 kPa soil water matric potential), greater total nitrogen, and numerically greater soil organic carbon under CC compared with NC management. This led to numerically greater microbial biomass and community composition (e.g., arbuscular mycorrhizal fungi, gram-negative and gram-positive bacteria, eukaryotes, and fungi), and slightly lower microbial stress indicators (genotypic and chemical structure categorizations) under CC compared with NC management. However, the lack of significant differences between treatments suggests that three years is insufficient to detect improvements in measured soil health indicators. Further, the significant differences in measured soil health indicators between study sites suggests an influence of soil texture and order, and this warrants further investigations.

Cover crop systems impact on biomass production, carbon-to-nitrogen ratio, forage quality, and soil health in a semi-arid environment

Cover cropping is a soil restorative strategy that can save degraded soils and offer additional benefits relative to the traditional fallow-based practice in semi-arid cropping systems. This study aimed to (i) quantify the above (shoot)- and belowground (root) biomass production, nutritive value, and tissue carbon and nitrogen concentrations from different annual cool-season cover crop systems, and (ii) determine their effects on soil organic carbon, total nitrogen, soil respiration, and soil microbial population biomass in a semi-arid environment. Treatments used were monocultures of annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), faba bean (Vicia faba L.), yellow sweetclover [Melilotus officinalis (L.) Lam], winter pea (Pisum sativum L.), two three-species mixtures (Mix 1: annual ryegrass + faba bean + yellow sweetclover and Mix 2: Oat + faba bean + winter pea), and a fallow laid out in a randomized complete block design with three replications. Averaged across years, Mix 2 produced greater shoot biomass (9714 kg DM ha−1; SE = 699) than all other cover crop systems except, the monoculture of oat (7970 kg DM ha−1; SE = 699). The plant tissue C/N ratio of the mixtures and monoculture legumes was mostly similar (range = 19.4–29.1). Overall, legumes produced superior relative feed value (RFV; 112–161) compared to grass monocultures and mixtures (RFV; 80–95). Soil gram-negative bacteria biomass was greatest under the yellow sweetclover monoculture. Based on the results of this study, the mixed cover crop systems (Mix 1 and Mix 2) offered a better chance of fulfilling the dual role of soil health improvement and feed quality for livestock in this semi-arid environment.

Tillage and cover crops effects on crop yield in wheat double‐cropping systems

AbstractThe United States is experiencing longer crop growing season in most states, which could afford producers the opportunity to diversify into double‐cropping (DC) and cover crop systems rather than the predominant summer and winter fallow systems. Thus, this study evaluated DC and cover crops effects on wheat (Triticum aestivum L.), cotton (Gossypium hirsutum L.), and soybean (Glycine max) yield under conventional tillage (CT) and no‐tillage (NT). Summer cover crops (SCCs) were sunn hemp (Crotolaria juncea L.) and sorghum sudangrass (Sorghum bicolor), while winter cover crops (WCCs) were Austrian winter pea (Pisum sativum) and wheat. Cropping systems were wheat‐fallow (W‐F), wheat‐cotton (W‐C), wheat‐soybean (W‐S), W‐SCC, WCC‐C, F‐C, WCC‐S, and F‐S. Tillage effect on crop yields varied across years. In 2021, wheat yield in CT of W‐C, W‐F, and W‐SCC (2831, 2689, and 2646 kg ha−1) significantly differed from NT of W‐S (1720 kg ha−1). No significant tillage effect was observed on cotton lint yield between W‐C and WCC‐C. For soybean, in 2020, the CT of W‐S and WCC‐S significantly outyielded the NT of W‐S and WCC‐S. Cropping system effect on wheat yield between W‐S and W‐SCC (1419 and 1987 kg ha−1) was significant in 2020 due to low stand counts in W‐SCC arising from the thick SCC biomass. Cotton lint yield in WCC‐C outyielded W‐C in all 3 years but was not significant. Soybean grain yield in W‐S was consistently higher than in WCC‐S, though not significant. Cotton lint and soybean grain yield in the fallow systems were the least. Overall, in a short term, crop yield in DC and cover crop systems were similar.

Winter cover crops and irrigation alter soil microbial community composition in an arid cropping system

Cover cropping is a well-established strategy to improve soil health, especially in arid and semi-arid agricultural systems. Benefits to soil health are often mediated via effects of cover crops on soil microbial community structure, function and diversity, crucial for regulating soil biogeochemical cycles, eventually promoting agricultural sustainability. However, limited water availability is a major constraint for both cover crop growth and soil microbial activity. This study sought to characterize and elucidate the shifts in soil microbial community structure in response to different cover crops and differential irrigation treatments using phospholipid fatty acid (PLFA) profiling in southern New Mexico. We tested five cover crop treatments: Pisum sativum (Australian winter pea), Hordeum vulgare cv. Stockford (barley), Brassica juncea cv. Caliente 199 (brown mustard), a three-way mix, and a fallow control — in combination with irrigation treatments of one, two, or three irrigation applications — in a split-plot design over two years. Zea mays (sweet corn) was grown as the summer cash crop. We collected soil samples just after cover crop planting in the fall of 2018, following second year cover crop termination but during Z. mays growth in June 2020, and after the second season of Z. mays growth in October 2020. Differential irrigation treatments did not lead to consistent patterns of change under any cover crop or irrigation treatment. However, PLFA parameters in cover cropped compared to winter fallow plots tended to decrease under one and three irrigations but increased with two irrigations. Changes were more common for bacterial than for fungal PLFA biomarkers, and more common in B. juncea and H. vulgare cover crops than in P. sativa or the mix. It is important to note that, while cover crop effects were inconsistent, cover cropping did lead to some shifts in PLFA biomarkers, even in the short two-year period of cover cropping.

Nitrous oxide fluxes during a winter cover crop season in a Mississippi corn cropping system

Agroecosystems are the largest source of anthropogenic N2O fluxes. While cover crops (CC) offer benefits for soil health, their impacts on greenhouse gas fluxes are inconsistent. In the southeastern US, where intensive agriculture and low CC adoption are prevalent, few studies have investigated CC impact on soil N2O fluxes. Our study explored the effects of CC species and management practices on soil N2O fluxes during the winter CC growing season in Mississippi, which was conducted in a non-tilled corn cropping system with seven CC treatments. We measured in situ soil N2O fluxes, along with soil moisture and temperature, throughout the CC growing season from 2022 to 2023. Surface soil samples were also collected to analyze soil mineral nitrogen (N) content and enzyme activity. Over the study period (a total of 188 days), cumulative N2O fluxes were 0.50–1.03 ​kg N2O–N ha−1, with the lowest values from the annually-rotated Elbon rye treatment and the highest from the annually-rotated Austrian winter pea. Our results show that both CC treatments and sampling time significantly affected soil N2O fluxes. There was a strong positive correlation (r ​= ​0.34, p ​< ​0.05) between N2O fluxes and NO3–N content, which was lowest under continuous rye and rotated-rye treatments (0.31 and 0.34 ​mg ​kg−1 ). The results suggest that Elbon rye effectively reduced soil N2O fluxes during this period by lowering the soil NO3–N content, the primary substrate for denitrification. This study is one of the few studies to examine the impacts of cover crops on soil N2O fluxes in cropping systems in the southeastern US, offering insights into the cover crop effects on soil N2O fluxes during their growing season.

Cereal–Legume Intercropping: Which Partners Are Preferred in Northwestern Europe?

To increase Europe’s self-sufficiency for protein sources, boosting plant protein production is a prerequisite. Yield variability is one of the main problems regarding the cultivation of protein crops. In this light, cereal–legume intercropping can offer a solution, as well-balanced intercropping systems are less prone to yield variations. Therefore, in this study the effects of (i) species/genotype combination, (ii) intercropping sowing densities and (iii) fertilizer regime were evaluated under Belgian (Northwestern European) conditions over three years (i.e., the 2020–2021, 2021–2022 and 2022–2023 seasons). Regarding the species combinations, winter barley x winter pea, winter wheat x winter faba bean and winter triticale x winter faba bean, it was observed that the best-performing combination varied from year to year depending on the prevailing weather conditions. A reduced sowing density (i.e., 130 seeds/m2 for the cereal partner and 20 seeds/m2 in the case of faba bean or 40 seeds/m2 in the case of pea) was sufficient to achieve competitive yields under the prevailing conditions. Inoculation with commercial Rhizobium strains did not result in an increased yield. Fertilization with one or two nitrogen fractions significantly increased the total yield thanks to a yield increase in the cereal partner; however, as a consequence, the proportion of legumes in the mixture decreased. In conclusion, it can be stated that with the investigated cereal–legume combinations, a competitive yield and qualitative protein yield can be achieved with a reduced fertilizer input.

Clay soil amendment suppressed microbial enzymatic activities while increasing nitrogen availability in sandy soils

AbstractConservation management practices often produced positive but limited desirable outcomes in US Southeast sandy soils, likely due to their intrinsically low clay contents that constrain the soil's capacity to preserve organic carbon (C) and nutrients. In the field, we tested the effectiveness of a novel approach, that is, clay soil amendment, to improve sandy soils. In October 2017, clay‐rich soils (25% clay) were spread at 25 metric tons ha−1 and tilled onto a sandy soil (1.9% clay) in the field, which was further mixed by light tillage at 0‐ to 15‐cm depth, followed by planting winter cover crop mixtures (cereal rye, crimson clover, and winter pea). The crop rotation was cotton and corn with cover crop mixtures planted in the winter fallow season. Soils (0–15 cm) were collected in August 2021 and subjected to physio‐biochemical analyses. Clay amendment increased soil clay content to 3.4%, which improved nitrogen (N) availability by 51% but inhibited the activities of C (β‐d‐cellubiosidase [CB]; β‐xylosidase [BX]; N‐acetyl‐β‐glucosaminidase [NAG]) and N (leucine aminopeptidase [LAP]) cycling enzymes, resulting in up to 78% reduction in microbial respiration. A follow‐up kinetic study on BG and LAP enzymes suggested that clay addition can have different impacts on enzymes with diverse biological origins through distinct mechanisms. Clay addition can potentially improve sandy soils by stabilizing the organic inputs in soils. However, more research is required to understand its long‐term impacts making this approach practical.

Effects of Straw Returning on Soil Aggregates and Its Organic Carbon and Nitrogen Retention under Different Mechanized Tillage Modes in Typical Hilly Regions of Southwest China

Tillage modes and straw returning influence soil aggregate stability and the distribution of organic carbon (C) and nitrogen (N) in aggregates of different particle sizes. In the typical hilly regions of southwest China, the predominant soil type is purple soil, characterized by heavy texture and high stickiness, with relatively lower soil fertility compared to other soil types. The improper use of fertilizers and field management practices further exacerbates soil compaction. However, abundant straw resources in the region provide an opportunity for comprehensive straw utilization. The effective utilization of straw resources is of significant importance for stabilizing agricultural ecological balance, improving resource utilization efficiency, and alleviating ecological pressure. Previously, most studies have focused on the impact of different mechanized tillage systems on the physical and chemical properties of soil in hilly areas, while research on the preservation of water-stable aggregates’ organic C and N content remains limited. In this study, the soil properties of fields under a winter pea–summer corn rotation for two years were studied with regards to the effects of straw returning on its water-stable aggregate distribution, macroaggregate content (R0.25), mean weight diameter (MWD), geometric mean diameter (GMD), and the organic C and N content in soil aggregates of different particle sizes and at different depths. The effects of five different tillage modes were assessed, namely rotary tillage with straw mixed retention (RTM), conventional tillage with straw burial retention (CTB), no-tillage with straw covered retention (NTC), subsoiling with straw covered retention (STC), and no-tillage without straw retention (NT). Based on the study results, under different tillage modes, straw returning effectively enhanced the soil organic carbon (SOC) and total nitrogen (TN) reserves at the plow layer (0–30 cm), SOC increased by 17.2% to 88%, and TN increased by 8.6% to 85.9%. At the same time, the content of 0.25–2 mm aggregates increased under the straw-return treatments under different tillage patterns. The NT treatment had the lowest R0.25 and MWD and GMD values for soil aggregates at different depths, which were significantly different (p &lt; 0.05) from the other treatment modes. The correlation coefficients between SOC and soil aggregate stability indices ranged from 0.68 to 0.90, with most of them showing highly significant positive correlations (p &lt; 0.01). In conclusion, straw returning under different tillage systems has improved soil aggregate stability and promoted soil structure stability. Specifically, the STC treatment has shown more pronounced effects on soil improvement in the upper soil layer of the hilly regions in southwest China, while the RTM treatment is beneficial for improving the lower soil layer. Therefore, the comprehensive experimental results indicate that the combination of STC and RTM treatments represents the most promising mechanized tillage and straw returning practices for the hilly regions in southwest China.

Influence of cover crop residue and residual herbicide on emergence dynamics of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in grain sorghum

Abstract A field study was conducted from 2020 to 2023 at Kansas State University Agricultural Research Center near Hays, KS, to understand the emergence dynamics and periodicity of glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Watson) as influenced by cover crop (CC) residue and residual herbicide in grain sorghum [Sorghum bicolor (L.) Moench]. The study site was under a wheat (Triticum aestivum L.)–sorghum–fallow rotation with a natural seedbank of GR A. palmeri. Treatments included (1) fall-planted CC mixture [winter triticale (×Triticosecale Wittm. ex A. Camus [Secale × Triticum])/winter peas (Pisum sativum L.)/rapeseed (Brassica napus L.)/radish (Raphanus sativus L.)] after wheat harvest and terminated at triticale heading stage (next spring before sorghum planting) with glyphosate alone or (2) glyphosate plus acetochlor/atrazine, (3) chemical fallow (no CC but treated with acetochlor/atrazine and dicamba before sorghum planting), and (4) nontreated control (no CC and no herbicide). Results indicated that CC terminated with glyphosate plus acetochlor/atrazine had a delayed and reduced cumulative emergence of GR A. palmeri as compared with chemical fallow and CC terminated with glyphosate alone across all 3 yr. Compared with chemical fallow, the CC terminated with glyphosate alone and glyphosate plus acetochlor/atrazine required 66 to 643 and 105 to 1,257 more cumulative growing degree days, respectively, to achieve 90% cumulative emergence of GR A. palmeri across all 3 yr. The combined effect of CC residue with glyphosate plus acetochlor/atrazine reduced the total emergence counts of GR A. palmeri by 42% to 56% and 82% to 94% as compared with chemical fallow and nontreated control, respectively. These results suggest that fall-planted CC combined with a residual herbicide at termination can be utilized for GR A. palmeri suppression in grain sorghum.

Competition Indices and Economic Benefits of Winter Wheat and Winter Peas in Mixed Cropping

Intensive wheat production, which produces high yields through the excessive use of chemical inputs and non-renewable energy, is unsustainable in the long term. Innovative cultivation methods such as intercropping can address emerging challenges. This kind of plant association offers the possibility of achieving a balanced yield with the use of a natural nitrogen source. An experiment was conducted for three growing seasons (2020/2021, 2021/2022, 2022/2023) with a combination of three winter wheat varieties (GK Szilárd, Cellule, GK Csillag) and a winter pea variety (Aviron) in three sowing densities to determine the species interaction and the economics of mixed plots. The intercropping systems were evaluated in terms of the land equivalent ratio (LER), aggressivity (A), competitive ratio CR), actual yield loss (AYL), monetary advantage index (MAI), and intercropping advantage (IA). In almost all mixtures, the values of partial A, CR, and AYL indicated that wheat was more competitive than peas due to the overconcentration of mixtures. For MAI, the mixture Cellule/Aviron 75:50 was more profitable than the others in the first two years. Our results draw attention to the influence of the seeding rate, which can contribute to new directions for current research.

Efficiency of weed control in winter pea in the Right Bank Forest Steppe of Ukraine

Purpose. To analyze the features of weed control in winter pea in the Right Bank Forest Steppe of Ukraine. Methods. The research was conducted at the Salyvonky State Enterprise of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences of Ukraine (Bila Tserkva district, Kyiv region) in 2020–2023. The agronomic practices used in the experiment were conventional for the zone of insufficient moisture of the Right Bank Forest Steppe of Ukraine, with the exception of the studied elements. Results. The development of the concept of autumn weed control for winter pea from requires a fairly competent selection of herbicides, taking into account weather forecasts, the specifics of the effect of active substances on weeds and cultivated plants, etc., as conditions for sowing winter pea do not allow to effectively apply conventional weed control system with the use of soil tillage and, if necessary, the limited application of herbicides during the vegetation season. This is explained by the fact that the terms for soil preparation and sowing are quite limited, and soil herbicides at high air temperatures work unpredictably and have limited efficiency in case of moisture deficit. Herbicide Corum, developed by combination of active substances bentazone (480 g/l) and imazomox (22 g/l), had better indicators in terms of total efficiency at an increased application rate (1.5 l/ha) – 92.9% in the BBCH 12 and 91.7% in the BBCH 14. At the same time, the efficiency of an application rate of 1.25 l/ha was within 80%. The latter is probably related not only to the autumn conditions of application of the [reparation, but also to the fact that such species as Fumaria officinalis, Sinapis arvensis, Solanum nigrum and thistles sprouted later, when the main mass of weeds was already in a development stage that was less sensitive to low rates of the herbicide. Conclusions. The application of Corum herbicide in the BBCH 12 at an application rate of 1.25 l/ha contributed to the destruction of 73.8% and an application rate of 1.5 l/ha resulted in 86.7% of weeds. When the herbicide was applied in BBCH 14, the total efficiency of crop treatment at an application rate of 1.25 l/ha was higher by 2.4% and at a rate of 1.5 l/ha it was higher by 1.2% compared to application in the BBCH 12. This is due to the fact that Chenopodium album, Amaranthus retroflexus, Polygonum convolvulus, Persicaria maculosa, Solanum nigrum, Polygonum lapathifolium and thistles sprouted in the pea crops, and the herbicide was highly effective against them. On the other hand, weed plants that sprouted earlier continued to vegetate and were already less sensitive even to increased application rates of herbicide. The application of the maximum recommended application rates was, for the most part, the most effective measure to reduce the number of weeds in winter pea crops. At the same time, such rates affected crop plants, causing stress, especially in the late periods of growth and development, which further affected the formation of pea yield. Therefore, the use of herbicides in the late phases of crop development should be avoided.

Grouping of segetal vegetation of winter pea agrophytocenosis and its influence on crop productivity in the Right Bank Forest Steppe of Ukraine

Purpose. To study the species composition and the ratio of seed stocks in the soil of different biological groups of weeds in the agrophytocenosis of winter pea, and their influence on the yield formation depending on the sowing rate of the crop. Methods. Quantitative and weighting, agrochemical, analytical, and statistical methods were used. Results. Weeds that formed a significant seed stock, belonged to the families Chenopodiaceae (58%), Amaranthaceae (18%), Poaceae (9–11%), Brassicaceae (6%), Роlygonaceae (4.5–5.8%), and Asteraceae (1.5–2.2%). A significant raw and dry biomass was formed by Cirsium arvense (52 and 24 g/m2, respectively), Polygonum scabrum (46 and 22 g/m2), Thlaspi arvense (34 and 12 g/m2), Chenopodium album (34 and 14 g/m2), Polygonum convolvulus (27 and 13 g/m2), Sonchus arvensis (23 and 11 g/m2), Amaranthus retroflexus (21 and 10 g/m2), Ambrosia artemisiofolia (22 and 11 g/m2), Solanum nigrum (21 and 9 g/m2), Galium aparine (19 and 8 g/m2), Sinapis arvensis (18 and 8 g/m2), Setaria pumila, and Setaria viridis (9 and 4 g/m2). Conclusions. Changes in the productivity of winter pea at different degrees of weed infestation of the sowings were revealed. A significant influence of segetal vegetation on the crop yield was established at the pea seed sowing rate of 0.6 million seeds/ha, where the yield of the varieties ‘Enduro’ and ‘NS Moroz’ was only 3.01 and 3.13 t/ha, respectively. The density of segetal vegetation at the standard sowing rate of 1.1 million seeds/h and increased rate to 1.6 million seeds/ha did not affect the yield (3.33 and 3.34 t/ha, respectively). On thinned crops, weed infestation increases, which can affect the crop yield, as it has significant advantages for growth and competition with winter pea plants.

The Impact of Peach Rootstocks and Winter Cover Crops on Reproduction of Ring Nematode

Two peach rootstocks (‘Guardian’ and ‘MP-29’) and ten winter cover crops (rye, wheat, barley, triticale, oat, Austrian winter pea, crimson clover, balansa clover, hairy vetch, and daikon radish) were evaluated in a greenhouse environment to determine their suitability to host ring nematode, Mesocriconema xenoplax. Each crop was inoculated with 500 ring nematodes, and the experiments were terminated 60 days after inoculation. The reproduction factor (ratio of final and initial nematode population) ranged from 0 to 13.8, indicating the crops greatly varied in their host suitability to ring nematode. ‘Guardian’ has been known to tolerate ring nematode; however, results from the current study suggest the tolerance statement is anecdotal. Another peach rootstock, ‘MP-29’, was also a good host for ring nematode, suggesting an urgency to develop ring nematode-resistant peach rootstocks. Wheat supported the least to no nematode reproduction while pea supported the greatest reproduction. The rest of the cover crops were poor to good hosts to ring nematodes. Although planting cover crops in peach orchards is not common, employing non or poor host crops can help suppress nematodes in addition to having soil health benefits. Furthermore, peach breeding programs should focus on finding and introgressing ring nematode resistance in commercial rootstocks.

Legume cover cropping and nitrogen fertilization influence soil prokaryotes and increase carbon content in dryland wheat systems

Simple rotation systems as wheat (Triticum aestivum L.)-fallow practiced in semi-arid regions are currently being transformed by replacing fallow with winter pea (Pisum sativum L.). However, there is insufficient understanding of how such diversification of plant functional groups impacts the biological and chemical soil properties which drive ecosystem services. This study investigated how diversifying rotation system coupled with nitrogen (N) fertilization impacts the diversity and activity of microbial communities and other essential soil properties such as soil organic carbon (C). Soils from a long-term field experiment (Pendleton, OR, USA) were sampled in 2021 at two depths (0–5 cm and 5–10 cm) and characterized for microbial biomass carbon (MBC), prokaryote community composition and diversity (16 S amplicon sequencing), activities of enzymes involved in C, N, phosphorous (P) and sulfur (S) cycles and soil chemical properties. The results indicated that MBC and enzyme activity were greater in the wheat-pea rotation compared to wheat-fallow, while fertilization was not a significant factor for these properties. Enzyme activities normalized by MBC showed fewer differences suggesting that the impact is mostly due to differences in MBC. Replacing fallow with pea decreased alpha diversity metrics at both depths and for both the highest and the lowest level of taxonomic hierarchy, although the effects upon phyla richness were not statistically significant. Nitrogen fertilizer decreased the Shannon index and Shannon evenness, especially in the 5–10 cm depth. While communities at the amplicon sequence variant (ASV) level were clearly separated by the rotation system, they were less separated by fertilization which distinguished communities only in the wheat-fallow system. Redundancy analysis (RDA) followed by variance partitioning analysis (VPA) indicated that soil properties explained most of the variation in the community structure at the phylum level with rotation and fertilization having no unique contribution. This suggests that the effects of rotation and fertilization are mediated through the changes these practices induce upon other soil properties. Overall, the results show that changing wheat-fallow into wheat-pea cover crop systems increases some soil health indicators while decreasing diversity which suggests that no direct coupling exists between above and belowground biodiversity.

Soil thermal properties: influence of no-till cover crops

Soil thermal properties, which determine heat transport, can influence soil health parameters and crop productivity. The objective of this study was to evaluate the 2-year effects of no-till cover crops (CCs) and no-till no cover crop (NC) on soil thermal properties (thermal conductivity (λ), volumetric heat capacity ( CV), and thermal diffusivity ( D)). Two levels of CCs were used for this study: CC versus NC. The CCs included crimson clover ( Trifolium incarnatum L.), hairy vetch ( Vicia villosa Roth.), winter peas ( Lathyrus hirsutus L.), oats ( Avena sativa), winter wheat ( Triticum aestivum L.), triticale ( Triticale hexaploide Lart.), flax ( Linum usitassimum L.), and barley ( Hordeum vulgare L.). Soil samples were collected at 0–10, 10–20, and 20–30 cm depths and their λ, CV, and D were measured in the laboratory. Additionally, soil organic carbon, bulk density (BD), and volumetric water content (ϴ) at saturation, −33 kPa, and −100 kPa soil water pressures were measured. Results showed that BD was 18% and 14% higher under CC compared with NC management during 2021 and 2022, respectively. Furthermore, ϴ at all measured soil water pressures was slightly higher under CC compared with NC management during both years. As a result, λ and D were significantly higher under NC compared with CC management, while CV was significantly higher under CC compared with NC management, during both years and at all measured soil water pressures. Generally, soil thermal properties were directly proportional to ϴ, suggesting that ϴ may be the most important factor influencing soil thermal properties.

No‐till cover crop effects on the hydro‐physical properties of a silt loam

AbstractSoil hydraulic and physical properties can be influenced by various land management practices, and they determine water movement and storage within the vadose zone, with both agronomic and environmental effects. The objective of this study was to evaluate the effects of two such practices (no‐till [NT] and cover crops [CCs]) on soil hydraulic (e.g., saturated hydraulic conductivity [Ksat], and water retention) and physical (e.g., bulk density [BD], pore size distribution, air‐filled pore spaces [AFPSs], and water‐filled pore spaces [WFPSs]) properties. The CCs used included crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth.), winter peas (Lathyrus hirsutus L.), oats (Avena sativa), winter wheat (Triticum aestivum L.), triticale (Triticale hexaploide Lart.), flax (Linum usitassimum L.), and barley (Hordeum vulgare L.). Soil samples were collected and analyzed during 2021 and 2022 right before CC termination at 0‐ to 10‐cm, 10‐ to 20‐cm, and 20‐ to 30‐cm depths. Results showed that, during 2021 and 2022, BD was 18% and 14% higher, respectively, under NC compared with CC management, while Ksat was 2.2 and 1.9 times higher, respectively, under CC compared with NC management. Further, the non‐capillary pores were significantly (p ≥ 0.05) higher under CC compared with NC management during both years of study. As a result, the majority of the total pores under CCs were filled with air, while the majority of total pores under NC management were filled with water. Therefore, this CC mix may be useful in lengthening the growing period during wet seasons by increasing air‐filled pore spaces.

Cover Crop and Crop Rotation Effects on Tissue and Soil Population Dynamics of Macrophomina phaseolina and Yield Under No-Till System.

The effects of crop rotation and winter cover crops on soybean yield and colony-forming (CFU) units of Macrophomina phaseolina, the causal agent of charcoal rot (CR), are poorly understood. A field trial was conducted from 2011 to 2015 to evaluate (i) the impact of crop rotation consisting of soybean (Glycine max [L.] Merr.) following cotton (Gossypium hirsutum L.), soybean following corn (Zea mays L.), and soybean following soybean over a 2-year rotation and its interaction with cover crop and (ii) the impact of different cover crops on a continuous soybean crop over a 5-year period. This trial was conducted in a field with 10 subsequent years of cover crop and rotation treatments. Cover crops consisted of winter wheat (Triticum aestivum L.) and Austrian winter pea (Pisum sativum L. subsp. sativum var. arvense), hairy vetch (Vicia villosa Roth), and a fallow treatment was evaluated with and without poultry litter application (bio-cover). Tissue CFU of M. phaseolina varied significantly between crop rotation treatments: plots where soybean was grown following cotton had significantly greater tissue CFU than plots following soybean. Poultry litter and hairy vetch cover cropping caused increased tissue CFU, though this effect differed by year and crop rotation treatment. Soil CFU in 2015 was substantially lower compared with 2011. However, under some crop rotation sequences, plots in the fallow treatment had significantly greater soil CFU than plots where hairy vetch and wheat was grown as a cover crop. Yield was greater in 2015 compared with 2011. There was a significant interaction of the previous crop in the rotation with year, and greater yield was observed in plots planted following cotton in the rotation in 2015 but not in 2011. The result from the continuous soybean planted over 5 years showed that there were no significant overall effects of any of the cover crop treatments nor was there interaction between cover crop treatment and year on yield. The lack of significant interaction between crop rotation and cover crop and the absence of significant differences between cover crop treatments in continuous soybean planting suggest that cover crop recommendations for midsouthern soybean growers may need to be independent of crop rotation and be based on long-term crop needs.

Conservation tillage and residue management practices in rice improves stress tolerance of succeeding vegetable pea by regulating physiological traits in Eastern Himalayas

The majority areas of valley lands in the Himalayan foothills remains fallow after the rice harvest. Recycling of plant biomass with conservation tillage may help in enhancing soil water availability, crop physiological function and productivity under moisture stress hill environments of this region. The present study focused on three tillage practices viz., no-till (NT), minimum tillage (MT) and conventional tillage (CT) and five nutrient management (NM) practices viz., 100 % NPK, 50 % NPK, 50 % NPK + in-situ residue retention (ISRR), 50 % NPK + weed biomass (WB) and 50 % NPK + green leaf manure (GLM) in rice and their residual effect on physio-biochemical properties, yield attributes and produce quality traits of succeeding pea varieties (Arkel and Prakash). Results revealed that total leaf chlorophyll content in vegetable pea varieties Arkel and Prakash was 12.0 and 11.5 % higher under no-till (NT) followed by 11.9 and 10.6 %, respectively under minimum tillage (MT) as compared to conventional tillage (CT) in rice. Similarly, application of 50 % NPK+ green leaf manure (GLM) and 50 % NPK+ weed biomass (WB) enhanced total leaf chlorophyll content in pea by 6.50–8.17 % and 3.93–5.48 % for pea varieties Arkel and Prakash, respectively. Photosynthetic rate and leaf dry weight were found 40.4 and 80.2 % higher under MT in Arkel whereas transpiration rate (E) and shoot dry matter were 33.1 and 19.3 % higher in Prakash under MT. Leaf water potential and root-to-shoot ratio were found 22.6 and 16.5 % higher in Prakash under MT and NT compared to CT respectively. Leaf temperature and stomatal conductance were 8.67 % lower and 9.8 % higher under MT in Prakash respectively as compared to CT, whereas 4.8 and 13.0 % higher under 50 % NPK +GLM and 50 % NPK+WB as compared 100 % NPK. Leaf cell viability was 22.5 and 20.1 % higher under MT whereas leaf MDA content was 29.9 and 28.3 % higher under MT in Arkel and Prakash respectively. Leaf relative water content was significantly higher to the tune of 25.7 and 22.4 % under NT compared to CT whereas leaf cell membrane integrity was 41.3 and 40.4 % higher under NT for Arkel and Prakash. Higher pod protein was noticed under MT along with 50 % NPK+GLM (13.1 %), whereas total soluble sugar was recorded highest under NT with 50 % NPK+GLM (21.1 %) in Prakash and MT with 50 % NPK+GLM (18.3 %) in Arkel. However, in both varieties, lower TSS was recorded under CT and with 50 % NPK (14.2 and 11.2 %) and the reducing sugar was maximum under the application of 50 % NPK+WB as compared to 100 % NPK alone. For both varieties of pea, green pod yield was recorded highest under MT (4.76 & 5.89 t/ha) as compared to CT (4.76 & 6.17 t/ha) and NT (4.76 & 5.55 t/ha). While 50 % NPK+WB has recorded significantly highest green pod yield of Arkel, 50 % NPK+ GLM has caused the highest yield of Prakash. PCA executed on physiological traits explained the total variability to the tune of 85.50 %, thereby extracting three PC's viz., PC 1 (62.63 %), 12.58 %) and 10.28 %, respectively. Thus, the adoption of MT in rice followed by NT in winter pea with the application of 50 % NPK+WB or 50 % NPK+GLM is promising for better physiological traits and subsequently favoring the grain yield of pea under stressful hill environments of Eastern Himalaya.

Didymella pinodella: An Important Pea Root Rot Pathogen in France to Watch Out For?

Root rot pathogens restrict pea and wheat production globally. In the EU, pea and pea-based cereal mixtures are being promoted; however, root rot pathogen dynamics in such mixtures are poorly understood. Winter pea and wheat were grown either in pure stands or in mixtures in the field in western France, and the severity of root rot in pea, wheat, and their mixtures, as well as the key pathogens associated with these crops, were assessed. Disease severity was moderate in pea and low in wheat, with no effect of sowing pattern. Didymella pinodella, a previously unreported pathogen in the pea-root rot complex in France, emerged as the most dominant pathogen in pea. It also occurred in low frequencies in wheat. Subsequent greenhouse aggressiveness tests showed that ten of the commonly grown pea cultivars in France lack resistance to D. pinodella. Among the Fusarium spp. isolated, F. avenaceum was the most frequent, occurring at similar frequencies in pea and wheat. In conclusion, D. pinodella may be an important pea root rot pathogen in France and there is a lack of resistance in the tested pea cultivars. In addition, F. avenaceum is a shared pathogen of wheat and pea.