Impact Of Cover Crops Research Articles

Impact of Cover Crops on Insect Community Dynamics in Organic Farming

Manipulating cover crops as an integrated pest management strategy has recently gained popularity in both traditional and organic agroecosystems. However, little information is available for producers to make informed decisions about cover crop selection, management, and their potential use as a pest management tool. To address this, we conducted a two-year, four-season field experiment on the potential of various cover crops during the summer seasons of both years, followed by monocultures of cash crops during winters. We hypothesized that the cover crop treatments would attract beneficial insects and repel damaging herbivores in a species-specific manner, and the insect community dynamics would be bridged to the cash crops in the subsequent season. In addition, we hypothesized that cash crops would suffer lower herbivory damage following specific cover crop treatments. Our design comprised of three cover crops. Our results indicate that cover crops support beneficial insects during the early summer season, while the time of growing season doesnot affect herbivore abundance. Crop-specific effects were found for herbivore abundance with possible cascading effects on insect community as well as damage levels on the subsequent cash crop, but without any impact on the growth traits of the cash crop. Together, our data suggest that cover crops, when carefully selected, can be an integral part of a pest management strategy for sustainable agriculture.

Allelopathic Impacts of Cover Crop Species and Termination Timing on Cotton Germination and Seedling Growth

The integration of cover crops into cotton (Gossypium hirsutum, L.) production remains challenging. One potential negative impact of cover crops on cotton is allelopathy. Proper selection of cover crop species and termination timing could potentially reduce the impacts of allelopathy on cotton seedlings. Two studies were conducted to determine cotton germination and growth sensitivity to cover crop leachate, which were measured using (I) five cover crops species, including: oats (Avena sativa L.), hairy vetch (Vicia Villosa), winter pea (Lathyrus hirsutus), winter wheat (Triticum aestivum), and annual rye (Lolium multiflorum), and (II) a blend of cover crops at four termination timings, including: at planting, three weeks prior to planting, six weeks prior to planting, and a split termination, where a 25 cm band in the top of the bed was terminated six weeks prior to planting, and the remaining cover crop was terminated at planting (referred to as strip 6-wk). Samples for Experiment I were collected on May 24th and for Experiment II on March 22nd (Strip/6-wk and 6-wk), April 30th (3-wk), and May 11th (at planting) in 2018. The effect of 0 (deionized water), 25, and 50 (v/v) cover crop leachate extract on cotton seed germination was evaluated in a series of controlled environmental studies. All cover crop species’ leachates negatively impacted cotton germination and seedling growth (p < 0.05). Germination inhibition rates declined numerically by species, with winter pea ≥ hairy vetch ≥ oats ≥ annual rye ≥ winter wheat at the 50 v/v concentrations. Winter pea germination inhibition on cotton equaled 47.0% and cotton radicle length was decreased by 62.8%. Termination at planting suppressed cotton germination more than the other termination timings, with the 50 v/v treatment resulting in a germination inhibition of 60.0%. Proper selection of cover crop species and termination timing prior to planting cotton will be critical in maximizing the benefits and minimizing the risks of a cover crop.

Cover Crop Impact on Soil Organic Carbon, Nitrogen Dynamics and Microbial Diversity in a Mediterranean Semiarid Vineyard

Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season; soil respiration, determined by incubation experiments, microbial biomass and diversity was analyzed after CC burial. The microbial diversity was evaluated by bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA) and high-throughput sequencing of 16SrDNA. CC increased nitrate content and, although it had no relevant effect on SOC, almost doubled its active microbial component, which contributes to SOC stabilization. An unexpected stability of the microbial communities under different soil managements was assessed, fungal diversity being slightly enhanced under CT while bacterial diversity increased under CC. The complete nitrifying genus Nitrospira and plant growth-promoting genera were increased under CC, while desiccation-tolerant genera were abundant in CT. Findings showed that temporary CC applied in semiarid vineyards does not optimize the provided ecosystem services, hence a proper management protocol for dry environments should be set up.

Short-term grazing of cover crops and maize residue impacts on soil greenhouse gas fluxes in two Mollisols.

An integrated crop-livestock system (ICLS), when managed properly, can help in mitigating soil surface greenhouse gas (GHG) fluxes, especially carbon dioxide (CO2 ), methane (CH4 ), and nitrous oxide (N2 O). However, the impacts of an ICLS on GHG fluxes are poorly understood. The present study was conducted at two sites (northern Brookings [Brookings-N] and northwestern Brookings [Brookings-NW]) established in 2016 and 2017, respectively, under loamy soils in South Dakota. The specific objective was to evaluate the impact of cover crops (CCs) and grazed CCs under oat (Avena sativa L.)-CCs-maize (Zea mays L.) rotation on GHG fluxes. Study treatments included the following: (a) a legume-dominated CC (LdC), (b) a cattle-grazed LdC (LdC+G), (c) a grass-dominated CC (GdC), (d) a cattle-grazed GdC (GdC+G), and (e) one without CC or grazing (NC). Greenhouse gas monitoring occurred weekly during the growing crop seasons in 2016 and 2017 for Brookings-N and in 2017 and 2018 for Brookings-NW. Data showed that cumulative CO2 and N2 O fluxes at Brookings-N were lower for GdC+G (4042 kg C ha-1 for CO2 and 1499 g N ha-1 for N2 O) than for LdC+G (4819 kg C ha-1 for CO2 and 2017 g N ha-1 for N2 O), indicating the superiority of GdC+G over LdC+G in reducing GHG fluxes. However, no effect from grazed CC on cumulative CO2 and N2 O fluxes were observed at the Brookings-NW site. Cumulative CH4 flux was not affected by an ICLS at either site. This short-term investigation showed that, in general, CCs and grazing of CCs and maize residue did not impact GHG fluxes.

Cover crop impact on irrigated cotton yield and net return in the southern Great Plains

AbstractCover crops have the potential to increase ecosystem services of cropping systems, although mixed results have been found throughout the U.S. Great Plains. Crop performance and economic returns are often used by producers to gauge the feasibility of adoption. In addition, soil moisture use by cover crops is a concern in semiarid environments. The objective of this research was to determine the impact of cover crops on cotton (Gossypium hirsutum L.) yield and economic return compared with conventional practices in pivot irrigated systems of the southern Great Plains. A 6‐yr study was conducted at the Texas A&M AgriLife Chillicothe Research Station evaluating the following treatments: (i) conventional till (CT); (ii) no‐till (NT); (iii) NT with winter wheat (Triticum aestivum L.) cover crop (NT‐W); and (iv) NT with a multi‐species cover crop mixture (NT‐M). Cotton yields, expenses, and returns were determined over a 6‐yr period (2013–2018). No significant treatment effect was determined for crop yield. Compared to NT, lint yields were increased 9.5% by NT‐M and 9.4% by NT‐W. Cover crop treatments significantly increased total costs compared to NT. However, net returns were 12% greater for NT‐W and 8% greater for NT‐M compared to NT. Over the 6‐yr study, NT‐M did not provide an agronomic or economic advantage over NT‐W. Under irrigated conditions in the southern Great Plains, cover crops were implemented without negatively affecting lint yield or net returns in continuous cotton systems at seeding rates of 34 kg ha–1.

Impact of Cover Crops on the Soil Microbiome of Tree Crops.

Increased concerns associated with interactions between herbicides, inorganic fertilizers, soil nutrient availability, and plant phytotoxicity in perennial tree crop production systems have renewed interest in the use of cover crops in the inter-row middles or between trees as an alternative sustainable management strategy for these systems. Although interactions between the soil microbiome and cover crops have been examined for annual cropping systems, there are critical differences in management and growth in perennial cropping systems that can influence the soil microbiome and, therefore, the response to cover crops. Here, we discuss the importance of cover crops in tree cropping systems using multispecies cover crop mixtures and minimum tillage and no-tillage to not only enhance the soil microbiome but also carbon, nitrogen, and phosphorus cycling compared to monocropping, conventional tillage, and inorganic fertilization. We also identify potentially important taxa and research gaps that need to be addressed to facilitate assessments of the relationships between cover crops, soil microbes, and the health of tree crops. Additional evaluations of the interactions between the soil microbiome, cover crops, nutrient cycling, and tree performance will allow for more effective and sustainable management of perennial cropping systems.

Impact of cover crop on corn–soybean productivity and soil water dynamics under different seasonal rainfall patterns

AbstractThe effect of cover crop (CC) on soil water balance and agricultural production is closely related to rainfall amount and distribution in rainfed cropping systems. This study used the root zone water quality model, RZWQM2, calibrated and validated with 4‐yr field measurements to predict the effect of planting a winter wheat (Triticum aestivum L.) CC in a no‐till rainfed corn (Zea mays L.)–soybean (Glycine max L.) rotation on soil water balance, crop yield, and grain water‐use efficiency (WUE) in northeast Mississippi. Seasonal rainfall for 80 consecutive years (1938–2017) was classified as ‘wet,’ ‘normal,’ and ‘dry’ years using frequency analysis, and the data sets matched chronologically to wheat, corn, and soybean growth periods were used as an input parameter in RZWQM2 simulations. During autumn and spring (early October to early April), the CC reduced deep drainage by 69 (11%), 53 (15%), and 51 mm (21%) in wet, normal, and dry years, respectively. Averaged across 40 yr, the CC decreased surface evaporation by 64 (32%) and 38 mm (24%) for corn and soybean growth periods, respectively. Wheat CC also improved soil water storage in early crop growth period during April–June in any of the three rainfall patterns. Regardless of rainfall patterns, the increase in WUE can be attributed to a decrease in evapotranspiration during cash crop period without sacrificing cash crop yield in the CC system. Introducing CC into cropping systems is beneficial to reduce annual deep drainage and evaporation while maintaining higher crop yields under different rainfall patterns.

Agronomic and economic impacts of cover crops in Texas rolling plains cotton

AbstractCover crops have been proposed as a resource that could enhance the effect of no‐till (NT) cropping systems. Crop yield limitations due to cover crops in the U.S. Great Plains are a concern to potential adopters. This research determined the impact of cover crops on crop yield and economic return compared with conventional practices in dryland systems of the Texas Rolling Plains. The study conducted at the Texas A&M AgriLife Chillicothe Research Station evaluated the following treatments: (a) conventional till (CT); (b) NT, and NT with the following cover crops; (c) Austrian winter pea (Pisum sativum L.); (d) hairy vetch (Vicia villosa L.); (e) crimson clover (Trifolium incarnatum L.); (f) winter wheat (Triticum aestivum L.); and (g) a multi‐species mixture. Cotton (Gossypium hirsutum L.) yields, expenses, and returns were determined over a 4‐yr period (2013–2016). Cover crops increased total seed costs compared to CT and NT. Hairy vetch and the multi‐species mixture increased total expenses over CT and NT. However, no significant treatment effect was determined for crop yield or net return among treatments. A multi‐species mixture did not provide an agronomic or economic advantage compared to single species cover crop approaches. Under dryland conditions in the Texas Rolling Plains, these selected cover crops maintained cotton yields without negatively affecting net returns. Other ecosystem services should be considered prior to implementing cover crops in studied cropping systems. Site‐specific research is warranted in regions of the southern Great Plains where water may be more limited than the Texas Rolling Plains.

Cover crop impact on crop production and nutrient loss in a no-till terrace topography

Increased emphasis on implementation of conservation practices (terraces, conservation tillage including no-till or reduced tillage, and cover crops [CC]) have led to the integration of best management practices. However, research on integration of best management practices is limited. Therefore, a field trial was established at the University of Missouri Grace Greenley Research Center near Leonard, Missouri, to evaluate the effects of terraces with landscape positions and CCs on soil health parameters, CC biomass accrual, and no-till corn (<i>Zea mays</i> L.)–soybean (<i>Glycine max</i> [L.] Merr.) yields. Additionally, total suspended solids (TSS), nitrate-nitrogen (NO₃-N), and total phosphorus (TP) export and discharge were evaluated from terraces with or without CCs. Six parallel terraces were installed at 36.5 m spacing with each consisting of an individual underground tile outlet. Soybean was planted in 2016 and 2018, and a CC blend was overseeded at R6. Corn was planted in 2017 and cereal rye (<i>Secale cereal</i> L.) CC was drill-seeded after corn harvest. Soil health parameters had significant (<i>p</i> &lt; 0.10) year by landscape position interactions for magnesium (Mg), potassium (K), total organic carbon (C), and clay content. Each of these parameters was same among landscape positions before terrace construction, and at least one of the landscape positions differed following terrace construction. Cover crop in terraces reduced soybean and corn grain yield by 12% and 6% in 2016 and 2017, respectively, and increased soybean yield 4% in 2018. Crop yield was greatest at the shoulder landscape position and lowest in the channel in all years. Terraces with CCs reduced TSS between 363 and 4,713 g ha⁻¹, TP between 2 and 90 g ha⁻¹, NO₃-N between 147 and 3,407 g ha⁻¹, and discharge between 41 and 81 m³ ha⁻¹ compared to no CC terraces. Two-year cumulative TSS, NO₃-N, and discharge from CC terraces was 41%, 52%, and 43% lower than the terraces with no CC. Cover crops did not affect cumulative TP loss. Cover crops were an effective tool for reducing discharge and nutrient loss in a no-till tile-terrace field.

Impact of Cover Crop Usage on Soilborne Diseases in Field Nursery Production

Soilborne pathogens are a significant economic problem for nursery production in the Southeastern United States. The goal of this study was to determine the impact of cover crops on soilborne disease suppressiveness in such systems. Soils from red maple (Acer rubrum L.) plantation fields grown with and without cover crops were sampled, either while the cover crops were growing (pre-disked) or post-season, following cover crop incorporation into the soil (post-disked). Greenhouse bioassays were conducted using red maple seeds on inoculated (with Rhizoctonia solani (J.G. Kühn) or Phytophthora nicotianae (Breda de Haan)) and non-inoculated field soils. The damping-off, root rot disease severity, percent recovery of Rhizoctonia and Phytophthora, and pseudomonad population were examined during the two years of the experiment. Results showed that cover crop incorporation was beneficial for inducing disease supressiveness characteristics of soil. Cover crop incorporation into the soil significantly or numerically reduced disease severity and pathogen recovery in infested soil compared to the bare soil treatment. Cover crop incorporation was found to be partially associated with the reduction of seedling damping-off. The pseudomonad microbial population was greater when cover crop was present, and is thought to be antagonist to soilborne pathogens. Therefore, cover crops can be integrated in field nursery production systems to suppress soilborne pathogens.

Integrating corn nitrogen management strategies and cover crops following winter wheat

Following winter wheat, there can be approximately a 90‐day fallow period with no crop N uptake and autumn soil temperatures &gt;50°F, leading to increased residual soil NO3–N availability. Opportunities exist for incorporation of cover crops to assimilate residual autumn soil N and reduce the potential for N loss. The objective of this study was to quantify daikon radish and forage oat cover crop biomass and N uptake, cover crop impact on soil NO3–N concentration, and corn growth, grain yield, and profitability responses to N placement and timing combinations following cover crops. Earn 1 CEU in Nutrient Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/699.

Impacts of Cover Crops and Crop Residues on Phosphorus Losses in Cold Climates: A Review.

The use of cover crops and crop residues is a common strategy to mitigate sediment and nutrient losses from land to water. In cold climates, elevated dissolved P losses can occur associated with freeze-thaw of plant materials. Here, we review the impacts of cover crops and crop residues on dissolved P and total P loss in cold climates across ∼41 studies, exploring linkages between water-extractable P (WEP) in plant materials and P loss in surface runoff and subsurface drainage. Water-extractable P concentrations are influenced by plant type and freezing regimes. For example, WEP was greater in brassica cover crops than in non-brassicas, and increased with repeated freeze-thaw cycles. However, total P losses in surface runoff and subsurface drainage from cropped fields under cold climates were much lower than plant WEP, owing to retention of 45 to >99% of released P by soil. In cold climatic regions, cover crops and crop residues generally prevented soil erosion and loss of particle-bound P during nongrowing seasons in erodible landscapes but tended to elevate dissolved P loss in nonerodible soils. Their impact on total P loss was inconsistent across studies and complicated by soil, climate, and management factors. More research is needed to understand interactions between these factors and plant type that influence P loss, and to improve the assessment of crop contributions to P loss in field settings in cold climates. Further, tradeoffs between P loss and the control of sediment loss and N leaching by plants should be acknowledged.

Impact of Cover Crop Management on Level of Weed Suppression: A Meta‐Analysis

We conducted a previous systematic and meta‐analysis review that showed differences in results from studies that evaluated the effectiveness of cover crops for weed suppression in cropping systems; these differences were largely due to management approaches used in growing the cover crop and main crop. The current meta‐analysis provides a quantitative review on how cover crop and main crop management practices influence the impact of cover crops on weed suppression. The meta‐analysis used observations from 53 studies published from 1990 to 2018. Cover crop biomass was inversely related to the amount of weed biomass (r2 = 0.67) and weed density (r2 = 0.64). In general, the meta‐analysis shows that cover crops provided a range of weed suppression depending on management decisions such as choice of cover crop species, cover crop sowing season (fall or spring), sowing dates within seasons, seeding rate, termination date, delay in main crop planting date after cover crop termination, tillage system under which the cover crop was produced, and integrating the cover crop with other weed control inputs. For example, grass cover crop species provided greater weed suppression than broadleaf species. Fall‐sown cover crops provided greater weed suppression (weighted mean of response ratio [R*] = 0.19) than spring‐sown cover crops (R* = 0.48) by the summer. Weed suppression increased by increasing seeding rate of cover crops from 1× (R* = 0.50) to 2× (R* = 0.27) or 3× (R* = 0.10). In addition, cover crops provided greater weed suppression in reduced tillage systems (R* = 0.19) than no tillage (R* = 0.29). The differential weed suppression provided by these management approaches suggests that a cover crop management approach should be rightly selected for weed suppression benefits.

Economic Impacts of Cover Crops for a Missouri Wheat–Corn–Soybean Rotation

In the United States, agricultural production using row-crop farming has reduced crop diversity. Repeated growing of the same crop in a field reduces soil productivity and increases pests, disease infestations, and weed growth. These negative effects can be mitigated by rotating cash crops with cover crops. Cover crops can improve soil’s physical, chemical, and biological properties, provide ground cover, and sequester soil carbon. This study examines the economic profitability for a four-year wheat–corn–soybean study with cover crops by conducting a field experiment involving a control (without cover crops) at the Soil Health Farm in Chariton County, MO, USA. Our findings suggested that economic profitability of the cash crop is negatively affected by the cover crop during the first two years but were positive in the fourth year. The rotation with cover crops obtained the same profit as in the control group if revenue from the cash crop increased by 35% or the cost of the cover crop decreased by 26% in the first year, depending on the cost of seeding the cover crop and terminating it. This study provides insights for policymakers on ways to improve the economic efficiency of cost-share conservation programs.

Cover Crops and Returning Residue Impact on Soil Organic Carbon, Bulk Density, Penetration Resistance, Water Retention, Infiltration, and Soybean Yield

Core IdeasResidue returned increased organic carbon and reduced bulk density compared to residue not returned.Residue returned increased water retention and infiltration compared to residue not returned.Residue returned and cover crop increased soil volumetric water content and water storage.Cover crop reduced bulk density and increased water infiltration compared with no cover crop.Cover crop increased the soybean yield by 14% compared with no cover crop.Residue management with cover crops (CC) can conserve soil moisture and thus has a potential to increase crop yield, but its effectiveness varies significantly by region and cropping system management. A study was conducted at Brookings, SD, on fine‐silty, mixed, superactive, frigid, Calcic/Pachic Hapludolls soils to understand the impact of CC and crop residue on soil properties and soil‐water dynamics for soybean (Glycine maxL.) crop grown after corn (Zea maysL.). The site had two crop residue treatments (residue returned [RR] and residue not returned [RNR]) under a no‐till corn–soybean rotation. Each residue returned treatment was later subdivided to include CC and no CC (NCC) treatments. Results from this 3 yr (2014, 2015, and 2016) study showed that RR (1.30 Mg m–3) had 7% lower bulk density (BD) compared to the RNR (1.40 Mg m–3). Soil organic carbon (SOC) was 22% higher under RR (26.2 g kg–1) compared to RNR (21.5 g kg–1). Soil water infiltration was 66% higher under RR (108 mm h–1) compared to RNR (64.8 mm h–1). Similarly, soil water infiltration in CC treatment (111 mm h–1) was 80% higher compared to NCC (61.7 mm h–1). The RR with CC treatment increased soil volumetric water content and soil water storage. Overall, the CC increased soybean yield by 14% compared to NCC. Data from this study suggest that the use of CC with RR are beneficial for improving soil properties, conserving soil moisture and enhancing crop yield.

The impact of cover crops and foliar application of micronutrients on accumulation of macronutrients in potato tubers at technological maturity stage

The impact of cover crops and foliar application of micronutrients on accumulation of macronutrients in potato tubers at technological maturity stage

Cover crops reduce water drainage in temperate climates: A meta-analysis

AbstractCover crops provide many ecosystem services, such as soil protection, nitrate pollution of water mitigation, and green manure effects. However, the impact of cover crops on soil water balance is poorly studied, despite its potential impact on groundwater recharge. Some studies reported a reduction of the water drainage due to an increase of the evapotranspiration by plant cover transpiration. However, there is no real consensus on the intensity of this phenomenon, which highlights the importance to quantify the impact of cover crops on drainage compared to that of bare soil. We performed a meta-analysis of published papers presenting studies on the impact of cover crops on drainage compared to that of bare soil under temperate climates. Of the 436 papers identified, 28 of them were included in the analysis based on criteria required for performing a relevant meta-analysis. The originality of our study lies in two following results: (1) the quantification of drainage reduction with cover crops by a mean effect size of 27 mm compared to that of bare soil and (2) within the large variability of soils, climates, and cropping systems, no main determining factor was found significant to explain the variability of water drainage reduction. The cover crops provide a service of nitrate pollution mitigation, but the drainage reduction could be considered as a disservice, because they can lead to a reduction in groundwater recharge due to a higher evapotranspiration in comparison to bare soil. This highlights the need of research for optimizing trade-offs between services and disservices of cover crops for water balance.

Cover Crop for Early Season Weed Suppression in Crops: Systematic Review and Meta‐Analysis

Core Ideas Cover crops can effectively suppress weeds after termination and up to early stage of crop growth. Use of cover crops for early season weed suppression did not affect grain crop yield, but improved yield of vegetable crops. Use of a single cover crop species provided early weed suppression similar to that of cover crop species mixtures. There were differences in cover crop and main crop management among studies that evaluated cover crop for weed suppression. Cover crops are gaining importance as their use has numerous benefits including improved soil health, reduced soil erosion, and weed suppression. Weeds are most competitive with crops at early growth stages, and a management strategy that ensures early season weed suppression in crops is crucial for crop growth, development, and yield. In this study, systematic and meta‐analytic reviews of published studies from 1990 to January 2017 were conducted to provide evidence on whether using cover crops can provide satisfactory weed suppression at termination of the cover crop and up to 7 wk after planting of the main crop. The impact of cover crops as a weed control input on main crop yield was also evaluated. A total of 46 relevant field studies were evaluated. Main crops were planted 1 to 3 wk after termination of the cover crops. Overall, our meta‐analysis results indicated that cover crops provided early season weed suppression comparable to those provided by chemical and mechanical weed control methods in cropping systems. The use of cover crops for early season weed suppression had no effect on main crop grain yields, but could increase vegetable crop yields when compared with no cover crop. Decisions about selecting cover crops species type (broadleaf or grass) or number (single or mixtures) were not as important as identifying cover crops with inherent characteristics that suppress weeds, such as high biomass productivity and persistent residue.

Soil Physical Quality in Sugarcane Field Under Cover Crop and Different Soil Tillage Systems

Currently, the management practices employed in Brazilian sugarcane plantations have contribute to soil physical degradation and, few studies considering the effect of cover crop associated with conservationist soil tillage systems to control or even reverse this process. Therefore, with the aim to assess the impact of cover crop and tillage systems on the least limiting water range (LLWR) and the S index in two soils of different textures used for sugarcane production, a fieldwork was carried out in two sugarcane plantations in the state of S&amp;atilde;o Paulo, Brazil. The experimental design is a split-plot with four repetitions. The main factor consisted of soil cover vegetation: cover crop and fallow, and the second factor, the tillage system: minimum tillage and conventional tillage. The data of this study demonstrated that clayey and medium-textured soil are sensitive to the management systems used. The use of cover crop promoted an increase of LLWR (average incremental rate of 105% for clayey and 100% for medium-textured soil) and S index (average incremental rate of 16% for clayey and 10% for medium-textured soil). The maintenance of soil under fallow represented restrictive conditions for the growth/development of the plants due to the degradation of the soil structure. In addition, conservation management systems, such as minimum tillage, resulted in better soil physical quality when associated with cover crop. Finally, the clayey and medium-textured soil, show good S index during the first cycle of sugarcane cultivation.

Cover Crops have Negligible Impact on Soil Water in Nebraska Maize–Soybean Rotation

Core Ideas The effect of cover crops on soil water storage for primary crops was evaluated. Field research was performed at sub‐humid and semi‐arid locations across Nebraska. Results indicate negligible impact of cover crops on soil water storage. Cover crop biomass was practically zero in west‐central Nebraska. One perceived cost of integrating winter cover cropping in maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems is the potential negative impact on soil water storage available for primary crop production. The objective of this 3‐yr study was to evaluate the effects of winter cover crops on soil water storage and cover crop biomass production following no‐till maize and soybean rotations. Locations were near Brule (west‐central), Clay Center (south‐central), Concord (northeast), and Mead (east‐central), NE. Treatments included crop residue only (no cover crop) and a multi‐species cover crop mix, both broadcast‐seeded before primary crop harvest and drilled following harvest. Pre‐harvest broadcast‐seeded cereal rye (Secale cereale L.) was also included in the last year of the study because rye was observed to be the dominant component of the mix in spring biomass samples. Soil water content was monitored using neutron probe or gravimetric techniques. Mean aboveground cover crop biomass ranged from practically 0 to ∼3,200 kg ha−1 across locations and cover crop treatments. Differences in the change in soil water storage between autumn and spring among treatments occurred in 4 of 20 location–rotation phase–years for the top 0.3 m of soil and 3 of 20 location–rotation phase–years for the 1.2‐m soil profile. However, these differences were small (&lt;11 mm for the top 0.3 m and &lt;26 mm for the 1.2‐m profile). In conclusion, winter cover crops did not have an effect on soil water content that would impact maize and soybean crop production.