Planting Cover Crops Research Articles

Residues of Symbiont Cover Crops Improving Corn Growth and Soil-Dependent Health Parameters

Cover crops have emerged as a crucial tool in promoting sustainable agricultural practices, particularly in improving soil quality and soil–plant health. This study investigates the impact of single cover crop plants each with varying fungal and/or bacterial symbiosis capacities in a pot experiment. The growth of non-symbiont Ethiopian mustard (Brassica carinata), the associative bacterium symbiont black oat (Avena strigosa) and the double (fungus–bacterium) endosymbiont broad bean (Vicia faba) was studied on three distinct soil types, namely a less-fertile sandy soil (Arenosol), an average value of loam soil (Luvisol) and a more productive chernozem soil (Chernozem). Beside the biomass production, nitrogen content and frequency of AM fungi symbiosis (MYCO%) of cover crops, the main soil health characteristics of electrical conductivity (EC), labile carbon (POXC) and fluorescein diacetate enzyme activity (FDA) were assessed and evaluated by detailed statistical analysis. Among the used soil types, the greatest biomass production was found on Chernozem soil with the relatively highest soil organic matter (2.81%) content and productivity. Double symbiotic activity, assessed by soil nitrogen content and mycorrhiza frequency (MYCO%), were significantly improved on the lowest-quality Arenosols (SOM 1.16%). In that slightly humous sandy soil, MYCO% was enhanced by 45%, indicating that symbiosis was crucial for plant growth in the less-fertile soil investigated. After the initial cover crop phase, the accumulated biomass was incorporated into the Luvisol (SOM 1.64%) soil, followed by the cultivation of corn (Zea mays, DK 3972) as the main crop. The results indicate that incorporating cover crop residues enhanced labile carbon (POXC) by 20% and significantly increased the FDA microbial activity in the soil, which positively correlated with the nutrient availability and growth of the maize crop. This study emphasizes the importance of selecting suitable cover crops based on their symbiotic characteristics to improve soil quality and enhance soil–plant health in sustainable agricultural systems.

Cover crop alters rhizosphere sediments to recruit plant growth-promoting microorganisms, enhancing peanut production

Peanuts are typically grown in continuous monoculture in China, leading to continuous cropping obstacles and reduced yields. Cover cropping is emerging as a pivotal strategy for enhancing soil quality and promoting sustainable agriculture. However, the effects of cover crops on the rhizosphere environment, and how they benefit subsequent crops, are not well understood. We hypothesize that planting cover crop ryegrass during the winter fallow period could alter peanut rhizosphere sediments, recruit plant growth-promoting microorganisms, and ultimately enhance peanut production. This study aims to fill this gap by investigating the impact of ryegrass cover cropping on rhizosphere sediments and peanut yield. Rhizosphere soil organic carbon, total nitrogen, pH, and soil enzymes, including sucrase, urease, N-acetyl-β-D-glucosaminidase, and β-glucosidase, were analyzed, along with metabolomics, 16S rRNA, and fungal ITS sequence analyses, under traditional planting management (TP) and long-term cover crop (CC) treatments. The results showed that CC treatment significantly increased rhizosphere pH, enhanced soil organic carbon and total nitrogen levels, and elevated soil enzyme activities compared to TP treatment. Metabolomic analysis revealed that CC treatment upregulated compounds such as D-pinitol, palmitoleic acid, fructose, sorbitol, and sucrose, while downregulated compounds including benzoic acid, dodecanoic acid, and carbamic acid. This alteration in metabolite composition influenced the recruitment and function of the microbial community. Specifically, CC treatment markedly enhanced the abundance of growth-promoting microbes such as Bacillus, Paenibacillus, Pseudomonas, Lysobacter, Bradyrhizobium, and Mortierell etc., which are involved in important functions such as chemoheterotrophy, nitrate reduction, and plant saprotroph. Simultaneously, there was a decrease in pathogenic microorganisms, such as Aspergillus flavus and Fusarium oxysporum. Moreover, CC treatment positively influenced peanut root growth, resulting in longer roots and ultimately increase pod yield by 21.15 % compared to traditional winter fallow practices. These findings underscore the potential of cover cropping with ryegrass to improve rhizosphere microecosystem components, and ultimately enhance peanut productivity, providing valuable insights for sustainable agricultural practices.

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.

Integrating Cover Crops into Soybean Systems in the Southern Great Plains: Impacts on Yield and Yield Components

The implementation of cover crops in crop rotation is a suggested soil health practice. As cover crops are not harvested and sold, they do not directly provide monetary gain to producers. Therefore, it is imperative that planting cover crops does not negatively affect the subsequent cash crop. However, there is no overall consensus in the literature regarding the effects of cover crops on cash crop yield. To better understand the effects of cover crops on soybean growth and yield in Oklahoma soybean systems, trials were conducted in Bixby, OK, in 2019 and Perkins, OK, in 2019, 2020, and 2021. The objectives of these trials were to (1) determine how different cover crop mixes affect soybean growth parameters and (2) determine if cover crops significantly influence soybean seed yield. Treatments within the trials included six cover crops and a fallow treatment. Soybeans were planted after the termination of the cover crops. Yield and growth parameter data were collected after harvest. No significant differences or consistent trends were detected in the yield among treatments. While cover crops had a significant impact on the number of three- and four-bean pods, no other differences in the growth parameters existed, and they never translated into significant yield differences. Based on our data, cover crops would not benefit the overall cash crop production in the continuous cover crop soybean system in Oklahoma. However, the fact that cover crops did not consistently or significantly reduce soybean yield allows growers to explore other benefits, such as weed management or soil health improvement.

Cover crops support the climate change mitigation potential of agroecosystems.

Cover crops have the potential to mitigate climate change by reducing negative impacts of agriculture on ecosystems. This study is first to quantify the net climate change mitigation impact of cover crops including land-use effects. A systematic literature and data review was conducted to identify major drivers for climate benefits and costs of cover crops in maize (Zea maize L.) production systems. The results indicate that cover crops lead to a net climate change mitigation impact (NCCMI) of 3.30 Mg CO2e ha-1 a-1. We created four scenarios with different impact weights of the drivers and all of them showing a positive NCCMI. Carbon land benefit, the carbon opportunity costs based on maize yield gains following cover crops, is the major contributor to the NCCMI (34.5% of all benefits). Carbon sequestration is the second largest contributor (33.8%). The climate costs of cover crops are mainly dominated by emissions from their seed production and foregone benefits due to land use for cover crops seeds. However, these two costs account for only 15.8% of the benefits. Extrapolating these results, planting cover crops before all maize acreage in the EU results in a climate change mitigation of 49.80 million Mg CO2e a-1, which is equivalent to 13.0% of the EU's agricultural emissions. This study highlights the importance of incorporating cover crops into sustainable cropping systems to minimize the agricultural impact to climate change.

Assessment of land use management and its effect on soil quality and carbon stock in Ebonyi State, Southeast Nigeria

Evaluating soil quality (SQ) resulting from land management use impact is important for soil carbon (C) monitoring, land sustainability and suitability. However, the data in less developed regions of Africa like Nigeria is scarce, limiting our understanding at global scale. The study evaluated land management use on soil quality in Ebonyi State, Nigeria, a representative region of Africa. Soil samples were collected in 2021 and resampled in 2022 from regions including five land use managements (FS = forest soil; GLS = grass land soil; ACS = alley cropping Soil; SDS = sewage dump-soils; CCS = continuously cultivated soil). Soil physical and chemical properties were analyzed and discussed. The results shows that soil physical properties (bulk density, hydraulic conductivity, aggregate stability) were significantly (P < 0.05) influenced by land use management. Moderate to high bulk density, very low hydraulic conductivity (HC), and low aggregate stability were observed across land management, suggesting potential inhibition to root penetration, poor aeration, and water infiltration. Improved land management practices such as planting of cover crops either for re-grassing or addition of crop residues could be adopted as conservative options for increasing soil quality and encourage additional soil C. Soil pH decreased with the increase in soil depth in all land uses for both years. A higher soil pH of 6.78 (slightly acidic) was seen in SDS and lower mean 6.0 (moderately acidic) was obtained in CCS at 0–20 cm in 2021. The average mean nitrogen content was rated “very high” (0.81 g kg−1 and 0.69 g kg−1) in 2021 and 2022 respectively, suggesting nitrogen might not be a limiting factor for plant growth in the region. During the 2021 and 2022 study periods, the overall average mean C stock were 12.71 g kg−1 and 15.87 g kg−1 respectively suggesting 3.1 g kg−1 C stock increment in 2022. Soil inorganic C also increased by 9.86 g cm−2 in 2022. The study provided crucial information about how land management use affected soil physico-chemical properties including C stock and suggested that C stock could be improved by adopting appropriate land management use practices. The results fill a data gap in under-studied regions, but also facilitate potential land management practices.

The effects of roller crimping direction for termination of fall sown cereal rye (Secale cereale L.)

Consensus around the optimal direction of roller crimping a row-planted cover crop has not been established. Several publications report crimping either parallel or perpendicular to the direction of cover crop planting with little to no justification apart from unpublished observations or hypotheses. This study explicitly compared the effects of roller crimping direction on crimping efficacy, weed suppression, and cash crop yield. At Elora, ON in 2020 and 2021, and Harrow, ON in 2021, a cereal rye ( Secale cereale L.) cover crop was planted in three orientations (north-south vs. east-west vs. no rye control) then terminated with a roller crimper parallel or perpendicular to the direction of planting. A sweet corn ( Zea mays L.) cash crop was planted either north–south or east–west in the same direction as roller crimping. A split plot treatment of weediness (weedy vs. weed-free) was applied. It was found that roller crimping direction did not have a consistent effect on rye mortality or number of upright tillers, nor did it affect weed control. However, total marketable sweet corn fresh weight decreased in perpendicular crimped rye compared to parallel crimping, despite equivalent cob counts. We did not find evidence in this study to suggest that perpendicular roller crimping improves ground cover and therefore weed suppression, contrary to other unpublished observations. Given the effect on sweet corn yield, roller crimping perpendicular to the direction of cover crop planting may not be a suitable practice. Alternative methods for improving cover crop-based weed control should be investigated.

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.

A native plant species cover crop positively impacted vineyard water dynamics, soil health, and vine vigor

Cover cropping is associated with multiple ecosystem and agronomic benefits. However, in irrigated orchards and vineyards of the dry, Western United States, cover crop adoption rates are low, often owing to concerns over their uptake of critical soil water. Regional concerns, such as this, must be addressed to identify sustainable agricultural practices that meet unique needs of diverse growing regions. A two-year study was conducted to determine the impacts of cover crops on soil water dynamics, soil health, and crop growth during the establishment of an Autumn King table grape vineyard in a semi-arid, Mediterranean climate, specifically the Central Valley of California. Phacelia (Phacelia tanacetifolia), a plant species native to the region, and an introduced species, rye (Secale cereale L. ‘Merced’), were planted as cool season cover crops in the interrow spaces of the grapevines and compared to a standard management practice of no cover crop interrow spaces. The cover crop treatments differentially impacted soil microbial biomass and soil aggregate stability, with the phacelia treatment enhancing both metrics from the first season. The phacelia treatment plots resulted in higher soil moisture beneath the vines in both years, while the rye treatment showed similar benefits only after two consecutive years of cover cropping. Vine vigor was also higher in the phacelia treatment, which was likely consequential of enhanced soil moisture in the rows. Compared to the rye, the phacelia had lower plant tissue carbon to nitrogen ratio and higher above ground plant biomass, which may underpin the soil health benefits associated with the phacelia, although variances in soil total carbon and nitrogen and ammonium and nitrate were not determined for any treatment. Altogether, we present information on cover crop plant traits that show quicker return on investment with regards to soil health improvements and water savings. Further, we demonstrate that cool season cover crops offered benefits for vineyard water productivity. In summary, for Mediterranean vineyards, cover crops can promote vineyard soil quality and be a component of sustainable water management.

Interseeded cover crops in wide‐row corn: An opportunity for northern cropping systems

AbstractCover crops are an effective way to reduce soil erosion and promote soil health. However, in North Dakota and other northern climates where corn (Zea mays L.) is an important commodity crop, killing frosts generally occur before harvest, leaving little opportunity for cover crop planting. By interseeding cover crops into corn during the growing season, the cover crops are given a longer period to establish. The purpose of this study was to identify the impact cover crops interseeded into wide‐row (60‐inch) corn have on soil water content and corn productivity. Two experimental sites were established in 2020 near Leonard and Rutland, ND. Both sites were organized into randomized complete block designs, with three cover crop treatments in Leonard (n = 9) and four cover crop treatments in Rutland (n = 16). Cover crops were no‐till drilled into the corn at the V4 growth stage. The cover crop treatments were diverse mixes developed to either provide pollinator habitat, overwinter, or winter‐kill. Throughout the growing season, soil gravimetric water content and cover crop biomass was monitored. At the end of the growing season, dry cover crop biomass ranged from 189 to 1445 lb ac−1. The presence and type of interseeded cover crops did not have a statistically significant effect on soil water content or corn yield. It is suspected the above average precipitation during the month of July led to adequate amounts of soil water for the entirety of the cover crop growing season, limiting the difference between treatments.

AIFARMS: Artificial intelligence for future agricultural resilience, management, and sustainability

AbstractThe AIFARMS Artificial Intelligence for Future Agricultural Resilience, Management, and Sustainability national AI institute brings together over 40 world‐class AI and agriculture researchers, with the common mission to develop foundational advances in AI and use them to ensure that future agriculture is environmentally friendly, sustainable, affordable, and accessible to diverse farming communities. Since its establishment in 2020, AIFARMS has advanced the state of the art in autonomous farming, cover crop planting, machine learning for improved outcomes from remote sensing, dynamic estimation of yield loss from weeds, and livestock management. The institute has prioritized the creation and utilization of high‐quality, openly available data sets for advancing foundational AI and tackling agricultural challenges. AIFARMS leverages a close partnership between UIUC and Tuskegee University to build programming for a skilled and diverse next‐generation workforce in digital agriculture. We are expanding the reach of AIFARMS outside of the current partners to collaborate with national AI institutions and international partners.

Seedcorn maggot response to planting date, cover crops, and tillage in organic cropping systems.

Seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is an economically important early-season pest of corn and soybean in the United States. Adult seedcorn maggot is attracted to decomposing plant residues for oviposition, creating potential management issues where growers typically use tillage to incorporate fertility amendments and to create a seedbed. The use of growing degree-day models to time planting dates is an important tool for effectively managing this pest, but their use has not been examined in organic crop production. Here, we report the results of experiments to determine the effects of cover crops, tillage, and relative planting date on seedcorn maggot in corn and soybean in 2 experiments: The first during the transition to organic from conventional management and the second during the 3 yr following organic certification in central Pennsylvania, United States. Overall, delaying the planting date by 1-2 wk reduced fly emergence in corn, but not in soybean in both experiments. Seedcorn maggot emergence was also consistently greater in corn than in soybean, with 6 times more flies in corn than in soy. About 15 times more seedcorn maggot flies emerged from corn in treatments in which cover crops were managed with tillage compared to treatments in which cover crops were terminated with a roller-crimper followed by no-till planting of corn. Fly emergence was negatively related to the proportion of legumes in the cover crop mixture preceding corn. These results can help inform soil, cover crop, and crop decisions for organic growers in the Mid-Atlantic United States.

The business case for carbon farming in the USA

U.S. agricultural producers are increasingly able to participate in private voluntary carbon initiatives that compensate their efforts to sequester CO2, reduce GHG emissions, and provide ecosystem services through eligible conservation practices. This study examines the potential effects of alternative private payment regimes (per practice vs. per output), prices paid to farmers relative to out-of-pocket costs (low vs. high), and the availability of information on CO2 sequestration (limited vs. full), on the adoption of cover crops and no-till in the United States, the resulting CO2 sequestration, and changes in farmers’ net returns. The analysis relies on a highly stylized model of heterogeneous farms calibrated with county-level agronomic data, and simulated for current estimates of GHG impacts of cover crop planting and no-till under different scenarios. Our results indicate that agricultural carbon markets can be profitable for U.S. farmers, although with substantial geographic variability, and that annual carbon sequestration could range between 17 and 75 million mtCO2e. Payments per output would incentivize higher carbon sequestration than payments per practice, but the former regime would be less favored by farmers as a unified group than the latter (due to lower aggregate net returns). However, if operators of farms with high carbon sequestration potential could decide the payment regime to be implemented, they would choose the payment per output regime (due to higher net returns per enrolled hectare). Total projected net changes in GHGs under payments per practice, based solely on county-average net GHG effects of cover crops and no-till, over-estimate actual total GHG sequestration (based on the entire distribution of net effects by county) by 2.1 and 14.2 million mtCO2e, or 18% and 21%, respectively.

Land Suitability for Pepper in Tanggamus Regency, Lampung Province, Indonesia

Pepper is one of the local commodities developed in Indonesia and has become an export commodity. Improving the productivity of pepper can be done through sustainable land management based on the characteristics of soils and their potential. Therefore, land suitability evaluation is needed to maximize land potential and minimize inhibiting factors for pepper plant growth. This study evaluated the characteristics, potential, and distribution of suitable land for pepper plant development in Tanggamus Regency, Lampung Province, Indonesia. Land suitability was evaluated by matching land characteristics with land suitability criteria for pepper plants. This criterion consists of four classes, namely highly suitable (S1), moderately suitable (S2), marginally suitable (S3), and not suitable (N). The soil's climate and physical and chemical properties were the land characteristics data used. Potential land availability was arranged based on land suitability classes by considering existing land use and forest area status. Soil types in Tanggamus Regency are Inceptisols, Entisols, Alfisols, Andisols, Oxisols, and Ultisols, with the most extensive distribution of soil types being Oxisol (Typic Hapludox). The distribution of relief in Tanggamus Regency is dominated by mountainous areas with very steep slopes (slope &gt;40%). Land suitability classes are moderately suitable (S2), marginally suitable (S3), and not suitable (N) with limiting factors, namely drainage, texture, soil pH, and erosion hazard/slope. Improvement can be made by planting according to contours, planting cover crops, applying lime and organic matter, and ensuring balanced fertilization. The development of pepper plants in Tanggamus Regency can be achieved through diversification and extensification, with a total area of potential land that can be developed of 73,995 ha.&#x0D; &#x0D; Keywords: land potential, land evaluation, limiting factor, pepper, soil characteristics

Soil texture, fertilization, cover crop species and management affect nitrous oxide emissions from no-till cropland

Cover crops reduce nitrate leached, but effects on nitrous oxide (N2O) emissions are mixed. Cover crops can reduce N2O emissions by reducing levels of mineral nitrogen (N) and surface soil moisture during spring. Cover crops can also increase N2O emissions by adding organic substrates, releasing N during decomposition, or increasing summer soil water content. Winter-killed cover crops can increase soluble organic C and N during periods of typically low microbial activity. We hypothesized that planting a cover crop mix of radish (Raphanus sativus)-crimson clover (Trifolium incarnatum)-rye (Secale cereale) would increase direct N2O emissions relative to no cover crop, and result in lower direct and indirect N2O emissions than planting radish alone. We also hypothesized that extending the cover crop growing season, by planting earlier and killing later, would increase direct N2O emissions during winter, decrease direct N2O emissions during summer, and decrease indirect N2O emissions. To address these hypotheses, we conducted two field experiments (on sandy and silty soils) over four site-years. We measured cover crop biomass and N content, soil mineral N concentrations, soil moisture, green canopy cover, soil porewater nitrate, direct N2O emissions, and estimated indirect N2O emissions. Nitrous oxide emissions were ~ 7.8 times greater at the silty than the sandy sites due to greater soil moisture retention. Site-years with high radish biomass exhibited greater direct N2O emissions than sites with low radish biomass following winter-kill. Indirect N2O emissions were decreased ~7 % by planting cover crops and by ~70 % by planting cover crops early. Fertilizer induced emission peaks were 8.2 times greater than all previous N2O emissions combined at a silty site. Our results suggested that soil texture and fertilization played an important role in direct N2O emissions, while cover crop species, biomass, and timing played a more important role in NO3 leached, and thus, indirect N2O emissions.

Three years of cover crops management increased soil organic matter and labile carbon pools in a subtropical vegetable agroecosystem

AbstractCover crops have been widely adopted to improve soil functions in agroecosystems, including providing carbon (C) inputs that can contribute to soil C sequestration. However, soil C changes may be slow after introducing cover crops in unfavorable environments for soil organic matter (SOM) accumulation, like the Southeast United States subtropical region characterized by a warm humid climate, and coarse‐textured soils. We examined labile C pools as potential early indicators of SOM changes after cover crop introduction in a sandy subtropical vegetable production system. We compared the effects of four cover crop monocultures namely two grasses [sorghum sudangrass, Sorghum bicolor × S bicolor var. Sudanese and pearl millet, Pennisetum glaucum (L.) R. Br.], two legumes (sunn hemp, Crotalaria juncea L., and cowpea, Vigna unguiculata Walp.), and one four‐species mixture on soil organic carbon pools for 3 years. Soil samples were collected at a 15‐cm depth before cover crop planting and post cover crop incorporation to assess changes in SOM, permanganate‐oxidizable carbon (POX‐C), mineralizable carbon (Cmin), and water extractable organic carbon (WEOC). The incorporation of cover crops increased concentrations of SOM, POX‐C, and Cmin in year 3 relative to their baseline values in year 1. Concentration of SOM increased by 0.24 ± 0.05% (mean ± standard error) after 3 years of cover crop management. However, concentrations of WEOC significantly decreased in years 2 and 3 relative to the baseline. Monocultures and the mixture had similar effects on measured C pools, likely due to comparable aboveground biomass production. Our findings highlight the potential of POX‐C and Cmin as early indicators of SOM accumulation driven by cover crops use, as well as the capacity of cover crops to build SOM in similar subtropical systems and coarser textured soils.

Improving semi-arid agroecosystem services with cover crop mixes.

Winter wheat (Triticum aestivum, L.) production in the semi-arid US Northern High Plains (NHP) is challenged by frequent droughts and water-limited, low fertility soils. Composted cattle manure (compost) and cover crops (CC) are known to provide agroecosystem services such as improved soil health, and in the CC case, increased plant diversity, and competition with weedy species. The main concern of planting CC in winter wheat fallow rotation in regions that are more productive than the NHP, however, is the soil moisture depletion. It is unknown however, whether addition of CC to compost-amended soils in the NHP will improve soil properties and agroecosystem health without compromising already low soil water content. The main objective of this study was to assess the effects of four CC treatments amended with compost (45 Mg ha-1) or inorganic fertilizer (IF) (.09 Mg ha-1 mono-ammonium phosphate, 11-52-0 and 1.2 Mg ha-1ammonium sulfate, 21-0-0) on the presence of weeds, soil and plant total carbon (C), nitrogen (N), and biological dinitrogen (N2) fixation (BNF). Mycorrhizal Mix (MM), Nitrogen Fixer Mix (NF), Soil Building Mix (SB), a monoculture of phacelia (Phacelia tanacetifolia Benth L.) (PH), and a no CC control (no CC) were grown in native soil kept at 7% soil moisture in a greenhouse for a period of nine weeks. When amended with compost, MM was the most beneficial (48 g m-2 BNF and 1.7% soil C increase). SB had the highest germination, aboveground biomass, and decreased weed biomass by 60%. It also demonstrated the second highest amount of BNF (40 g m-2) and soil C increase by 1.5%. On contrary, IF hindered BNF by almost 70% in all legume-containing CC treatments and reduced soil C by 15%.

Safety Risk Assessment of an Autonomous Agricultural Machine

Highlights The safety guidelines outlined in ISO 18497 are not sufficient to guarantee the safe operation of autonomous agricultural machines. Since the risk assessment techniques specified in ISO 12100:2012 require historical failure data of the machine at hand, they cannot be used to effectively mitigate the risk associated with autonomous agricultural machines where such data are not readily available. Analysis from the perspective of ergonomics can potentially increase the safety of autonomous agricultural machines. Abstract. The goal of this study was to analyze the safety implications of an autonomous agricultural machine (TerraPreta) using the standards ISO 18497 (ISO, 2018) and ISO 12100:2012 (ISO, 2012), as well as to investigate the ergonomics associated with the use of the autonomous agricultural machine. First, three engineers involved in the robot's manufacturing process were asked to evaluate the robot's functionalities compliance with the applicable safety standards and protective measures outlined in standard ISO 18497 (ISO, 2018). Second, while the robot was planting cover crop seeds, an attempt was made to identify and evaluate every risk connected to the robot using the risk assessment techniques outlined in ISO 12100:2012 (ISO, 2012). (1) Half (50%) of the functionalities of the autonomous agricultural machine complied with the safety requirements and protective measures described within the standard ISO 18497 (ISO, 2018). (2) The heavy reliance on past incident data of the risk assessment procedure described within the standard ISO 12100:2012 (ISO, 2012) makes it ineffective for new and revolutionary technologies such as autonomous agricultural machines where such data are not available. (3) Lifting a bag to fill the robot hopper with seeds was found to be a moderately hazardous activity associated with human-robot interaction. Multiple tentative solutions were provided to avoid this moderately hazardous activity. Keywords: Autonomous agricultural machine, Ergonomics, Machine safety, NIOSH lifting equation, Risk assessment, Standards.

Effect of beef heifer development systems utilizing corn residue and late summer planted cover crops on growth, reproductive performance, and economics.

The objective of this study was to evaluate growth and reproductive performance of heifers developed using 3 different winter systems in the midwestern U.S. Spring-born heifers (n = 1,156; 214 d of age; SD ± 17 d) were used in a 3-yr study to evaluate performance in winter development systems, which utilized cover crop (CC) and corn residue grazing. Heifers were assigned to 1 of 3 treatments: grazing corn residue with 0.77kg/d dried distillers grains (CD) or 1.69kg/d wheat midds (CW) supplementation followed by a grower ration in the drylot, or grazing late summer planted oat-brassica CC followed by corn residue grazing with 0.35kg/d dried distillers grains supplementation (CC). Supplementation during the corn residue phase was targeted to result in a common body weight (BW) (276kg; ~45% of mature BW) by the end of the winter development period. Grazing of corn residue (CD and CW) and CC began in early November. After 63 d, heifers assigned to CC were moved to corn residue; on day 77 heifers assigned to CD and CW began receiving a grower ration in the drylot. In mid-February (day 98), heifers were comingled and managed in a single group. Breeding season began in June and lasted for 29 d. The ADG of heifers assigned to CC when grazing CC (days 1 to 63) was greater (0.76kg/d; P < 0.01) than those assigned to CD or CW (0.58kg/d and 0.49kg/d, respectively). Gain during the last 35 d of the winter period for heifers assigned to CC (0.36kg/d) was less (P < 0.01) than those assigned to CW (0.49kg/d) but not different from CD heifers (0.41kg/d). Overall (days 1 to 98), winter ADG was greater (P < 0.05) for heifers assigned to CC (0.62kg/d) than CD (0.53kg/d) or CW (0.50kg/d), which did not differ (P = 0.42). Percent of mature BW in May (27 d pre-breeding) was greater (P < 0.01) for heifers assigned to CC (52%) than for those on CD and CW (50%), which did not differ (P = 0.64). Pregnancy rates were affected by treatment (P < 0.03), with heifers assigned to CC (76%) being greater than CW (64%) and CD heifers being intermediate (70%). When accounting for the differences in cost and the value of open and bred heifers, the economic return tended to differ (P = 0.07) among treatments, with CC and CW not differing (P ≥ 0.20) from CD but return for CC being $73 greater than CW (P = 0.02). Utilizing oat-brassica CCs early in the winter followed by a slower rate of gain while grazing corn residue with distillers supplementation appears to be as effective for developing beef heifers in the midwestern U.S. as supplementing distillers grains.

Cover crop management strategies affect weeds and profitability of organic no-till soybean

Abstract Cover crop residue retention on the soil surface can suppress weeds and improve organic no-till soybean (Glycine max) yield and profitability compared to a tilled system. Appropriate cereal rye (Secale cereale) fall planting date and termination methods in the spring are critical to achieve these benefits. A plot-scale agronomic experiment was carried out from September 2018 to October 2021 in Kutztown, PA, USA to demonstrate the influence of cereal rye planting date (September or October) and mechanical termination method [no-till (I &amp; J roller-crimper, Dawn ZRX roller, and mow-ted) and tilled (plow-cultivate)] on cover crop regrowth density, weed biomass, soybean yield, and economic returns. In one out of three years, the September rye planting accumulated more cover crop biomass than the October planting, but the regrowth of the rye after roller-crimping was greater with this planting date. Cover crop planting date had no effect on total weed biomass and demonstrated varying effects on soybean grain yield and economic returns. The Dawn ZRX roller outperformed the I &amp; J roller-crimper in effectively terminating cover crops, while the I &amp; J roller-crimper demonstrated more uniform weed suppression and led to greater soybean yields over a span of three years. Organic no-till strategies eliminated the need for tillage and reduced variable costs by 14% over plow-cultivated plots, and generated ~19% greater net revenue across the study period (no-till vs tillage = US $845 vs US $711 ha−1). Terminating cereal rye with roller-crimping technology can be a positive investment in an organic soybean production system.