scholarly journals Beyond soil health: the trophic effects of cover crops shape predator communities

2020 ◽  
Author(s):  
Carson Bowers ◽  
Michael D. Toews ◽  
Jason M. Schmidt

AbstractMaintaining habitat throughout the season in annual cropping systems provides resource stability for arthropod communities. Stabilizing resource availability should lead to diverse predatory communities and their associated ecosystem services such as biological control. There is a need for studies to test change in predator communities due to habitat provisioning and estimate associated food web responses. Here we quantified predator community structure and used molecular gut-content analysis to reconstruct predator food webs in response to winter cover crops (i.e. cereal and legume based) in a cotton agroecosystem. Predators were collected from experimental field plots during each major crop development stage in 2017 and 2018, and PCR was used to estimate predator roles and responses to cover crop treatments. Cotton planted into a rye cover crop residue promoted unique predator communities in the early and mid-season as compared to no-cover fields. Correspondingly, we observed dissimilar prey consumption among cover crop treatments. While predators consumed incidental pests at high frequencies (e.g. aphids), predation on key pests by natural enemies in this system was lacking. The use of winter cover crops and reduced tillage practices increased the consumption of alternative prey by natural enemies on seedling cotton, encouraging high predator diversity that aligns temporally with potential early season pest outbreaks. Therefore, cover crops should be further integrated into integrated pest management strategies.

2014 ◽  
Vol 30 (5) ◽  
pp. 473-485 ◽  
Author(s):  
Natalie P. Lounsbury ◽  
Ray R. Weil

AbstractOrganic no-till (NT) management strategies generally employ high-residue cover crops that act as weed-suppressing mulch. In temperate, humid regions such as the mid-Atlantic USA, high-residue winter cover crops can hinder early spring field work and immobilize nutrients for cash crops. This makes the integration of cover crops into rotations difficult for farmers, who traditionally rely on tillage to prepare seedbeds for early spring vegetables. Our objectives were to address two separate but related goals of reducing tillage and integrating winter cover crops into early spring vegetable rotations by investigating the feasibility of NT seeding spinach (Spinacia oleracea L.), an early spring vegetable, into winterkilled cover crops. We conducted a four site-year field study in the Piedmont and Coastal Plain regions of Maryland, USA, comparing seedbed conditions and spinach performance after forage radish (FR) (Raphanus sativus L.), a low-residue, winterkilled cover crop, spring oat (Avena sativa L.), the traditional winterkilled cover crop in the area, a mixture of radish and oat, and a no cover crop (NC) treatment. NT seeded spinach after FR had higher yields than all other cover crop and tillage treatments in one site year and was equal to the highest yielding treatments in two site years. Yield for NT spinach after FR was as high as 19 Mg ha−1 fresh weight, whereas the highest yield for spinach seeded into a rototilled seedbed after NC was 10 Mg ha−1. NT seeding spring spinach after a winterkilled radish cover crop is feasible and provides an alternative to both high-residue cover crops and spring tillage.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 871A-871
Author(s):  
Mohan Selvaraj* ◽  
Mathieu Ngouajio

The inclusion of cover crops into cropping systems may influence soil microbial activity which is crucial to sustained crop production. A study was conducted to measure short term effects of summer and winter cover crops on soil microbial biomass carbon (MBC) in a cucumber-tomato rotation system. The experiment was established in Summer 2002 as a factorial of summer cover crops (planted either as fallow or after harvest of cucumbers) and winter cover crops (planted in September). The design was a split-block with four replications. The main plot factor was summer cover crop and consisted of five treatments; sorghum sudangrass fallow (SGF), cowpea fallow (CPF), sorghum sudangrass after cucumber (SGC), cowpea after cucumber (CPC) and bareground fallow (BGF). The sub-plot factor was winter cover crop and consisted of three treatments including cereal rye (CR), hairy vetch (HV) and bareground (BG). In spring of 2003, soil samples were collected in each treatment at 30 days before (30 DBI), 2 days after (2 DAI) and 30 days after (30 DAI) cover crop incorporation. MBC was measured using the chloroform fumigation-incubation method. Both summer and winter cover crops affected soil microbial activity. MBC in the summer cover crop treatments at 30 DBI was 47.7, 51.4, 49.2, 43.7 and 42.5 μg·g-1 soil for SGF, CPF, SGC, CPC and BGF, respectively. At 30 DAI, 113.1, 88.9, 138.5, 105.6, and 109.3 μg·g-1 soil was obtained in SGF, CPF, SGC, CPC, and BGF plots, respectively. Soil MBC was similar at 2 DAI in the summer cover crop treatments. Among winter treatments MBC was similar at 30 DBI and 30 DAI, but significant at 2 DAI with values of 62.8, 53.3, 59.3 μg·g-1 soil for CR, BG, and HV, respectively.


2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Mei Luo ◽  
Zinan Wang ◽  
Binjuan Yang ◽  
Lixia Zheng ◽  
Zhiwen Yao ◽  
...  

2014 ◽  
Vol 18 (12) ◽  
pp. 5239-5253 ◽  
Author(s):  
I.-Y. Yeo ◽  
S. Lee ◽  
A. M. Sadeghi ◽  
P. C. Beeson ◽  
W. D. Hively ◽  
...  

Abstract. Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990–2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha−1, but decreased to 4.6–10.1 kg ha−1 with cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~ 2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of cover crop implementation. Agricultural fields with well-drained soils and those that were more frequently used to grow corn had a higher potential for nitrate leaching and export to the waterways. This study supports the effective implementation of cover crop programs, in part by helping to target critical pollution source areas for cover crop implementation.


Author(s):  
Barbara Baraibar ◽  
David A. Mortensen ◽  
Mitchell C. Hunter ◽  
Mary E. Barbercheck ◽  
Jason P. Kaye ◽  
...  

2001 ◽  
Vol 16 (2) ◽  
pp. 66-72 ◽  
Author(s):  
F.J. Coale ◽  
J.M. Costa ◽  
G.A. Bollero ◽  
S.P. Schlosnagle

AbstractCereal rye is an effective winter cover crop because it accumulates residual soil N and reduces nitrate leaching. Wheat, barley, and triticale are alternative winter small grain species that may be managed as winter cover crops and yet produce marketable commodities. The objectives of this research were to evaluate N recovery capacity and grain yields of wheat, barley, triticale, and cereal rye grown as winter cover crops. Field plots established in 1996 and 1997 at two different locations on Maryland's mid-Atlantic Coastal Plain were amended with annual spring applications of four rates of broiler litter in a randomized complete block design with four replications. Each manure rate plot was divided into four subplots by planting four winter small grain cover crops: wheat, barley, triticale, and cereal rye. Rye cover crop treatments were killed with herbicide when the plants were 30 to 50 cm tall, while the wheat, barley, and triticale treatments continued to grow until grain maturity. Barley, rye, triticale, and wheat cover crops exhibited similar capacities to accumulate soil N, and therefore, reduce the potential for NO3—N leaching to groundwater. At the time of rye kill-down, aerial biomass N accumulation ranged from 11 to 112 kg N ha−1 and soil NO3—N levels were low (<1.5 mg NO3—N kg−1) and relatively uniform across treatments. Average barley, triticale, and wheat grain yields increased with previous broiler litter application rate and initial soil NO3—N concentration. Potential income derived from the grain and straw produced could partially or completely offset cover crop production costs.


Author(s):  
J. Peredo ◽  
C. Wayman ◽  
B. Whong ◽  
A. Thieme ◽  
L. R. Kline ◽  
...  

Abstract. Winter cover crops have been shown to limit erosion and nutrient runoff from agricultural land. To promote their usage, the Maryland Department of Agriculture (MDA) subsidizes farmers who plant cover crops. Conventional verification of cover crop planting and analysis of subsequent crop performance requires on-the-ground fieldwork, which is costly and labor intensive. In partnership with the MDA, NASA's DEVELOP program utilized imagery from Landsat 5, Landsat 8, and the European Space Agency’s Sentinel-2 to create a decision support tool for satellite-based monitoring of cover crop performance throughout Maryland. Our teams created CCROP, an interactive graphical user interface, in Google Earth Engine which analyzes satellite imagery to calculate the normalized difference vegetation index (NDVI) of fields across the state. Linear regression models were applied to convert NDVI to estimates of crop biomass and percent green ground cover, with measure of fit (R2) values ranging from 0.4 to 0.7. These crop metrics were implemented into an interactive filtering tool within CCROP which allows users to examine cover crop performance based on a variety of growing parameters. CCROP also includes a time series analysis routine for examining the progression of NDVI throughout the spring to help determine farmer-induced termination dates of cover crops. With this decision support tool, the MDA can analyze the effectiveness of cover crops throughout the state with reduced need to manually spot-check enrolled production fields, and can identify variables influencing overall cover crop performance to optimize implementation of their winter cover crop program via adaptive management approaches.


2022 ◽  
pp. 1-9
Author(s):  
Alyssa DeVincentis ◽  
Samuel Sandoval Solis ◽  
Sloane Rice ◽  
Daniele Zaccaria ◽  
Richard Snyder ◽  
...  

As fresh water supplies become more unreliable, variable and expensive, the water-related implications of sustainable agriculture practices such as cover cropping are drawing increasing attention from California's agricultural communities. However, the adoption of winter cover cropping remains limited among specialty crop growers who face uncertainty regarding the water use of this practice. To investigate how winter cover crops affect soil water and evapotranspiration on farm fields, we studied three systems that span climatic and farming conditions in California's Central Valley: processing tomato fields with cover crop, almond orchards with cover crop, and almond orchards with native vegetation. From 2016 to 2019, we collected soil moisture data (3 years of neutron hydroprobe and gravimetric tests at 10 field sites) and evapotranspiration measurements (2 years at two of 10 sites) in winter cover cropped and control (clean-cultivated, bare ground) plots during winter months. Generally, there were not significant differences in soil moisture between cover cropped and control fields throughout or at the end of the winter seasons, while evapo-transpirative losses due to winter cover crops were negligible relative to clean-cultivated soil. Our results suggest that winter cover crops in the Central Valley may break even in terms of actual consumptive water use. California growers of high-value specialty crops can likely adopt winter cover cropping without altering their irrigation plans and management practices.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1439
Author(s):  
Yesuf Assen Mohammed ◽  
Swetabh Patel ◽  
Heather L. Matthees ◽  
Andrew W. Lenssen ◽  
Burton L. Johnson ◽  
...  

Improved agronomic management strategies are needed to minimize the impact that current maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices have on soil erosion and nutrient losses, especially nitrogen (N). Interseeded cover crops in standing maize and soybean scavenge excess soil N and thus reduce potential N leaching and runoff. The objectives were to determine the impact that pennycress (Thlaspi arvense L.) (PC), winter camelina (Camelina sativa (L.) Crantz) (WC), and winter rye (Secale cereale L.) (WR) cover crops have on soil N, and carbon (C) and N accumulation in cover-crop biomass. The cover crops were interseeded in maize at the R5 growth stage and in soybean at R7 in four replicates over two growing seasons at four locations. Soil and aboveground biomass samples were taken in autumn and spring. Data from the maize and soybean systems were analyzed separately. The results showed that cover crops had no effect on soil NH4+-N under both systems. However, winter rye decreased soil NO3−-N up to 76% compared with no-cover-crop treatment in the soybean system. Pennycress and WC scavenged less soil N than WR. Similarly, N and C accumulation in PC and WC biomass were less than in WR, in part because of their poor growth performance under the interseeding practice. Until PC and WC varieties with improved suitability for interseeding are developed, other agronomic practices may need to be explored for improving N scavenging in maize and soybean cropping systems to reduce nutrient leaching and enhance crop diversification.


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