Does Grazing or Harvesting of Cover Crops Affect Soils and Crop Production? Assessment in Different Soil Types and Management Scenarios

View the project final report

• 2016 annual report

Commodities

• Agronomic: corn, rye
• Animals: bovine
• Animal Products: dairy

Practices

• Animal Production: winter forage
• Crop Production: catch crops, cover crops, no-till, nutrient cycling, conservation tillage
• Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research
• Farm Business Management: budgets/cost and returns
• Natural Resources/Environment: biodiversity, carbon sequestration
• Production Systems: integrated crop and livestock systems
• Soil Management: organic matter, nutrient mineralization, soil chemistry, soil microbiology, soil physics, soil quality/health

Cattle grazing of cover crops (CC) may fit the emerging integrated crop-livestock production systems, but its implications on soils and crop yields have not been widely researched. While many CC species can be a high quality source of feed for cattle, some people are concerned that grazing/harvesting CCs may adversely affect soil processes and properties (i.e., compaction, water infiltration, macroporosity) and concomitantly reduce soil productivity. Thus, tradeoffs between using CCs solely for soil cover and using them for animal feed must be comprehensively assessed. This interdisciplinary and farmer-oriented research project will assess  impacts of grazing/ harvesting of CCs on soil physical, chemical, and biological properties, soil fertility, water and wind erosion, grain yield, CC biomass, CC feed quality, and economics. This project will be executed across three farmers’ fields and two research sites in Nebraska. Treatments will include: 1) non-grazed/non-harvested CC 2) grazed/harvested CC, and 3) no CC under continuous corn, corn-soybean and corn-soybean-wheat rotations with three replications. We will assess: 1) subsequent grain yield, CC biomass, biomass post grazing/harvest, percent soil cover after grazing, and CC nutritive value, 2) soil structural, compaction, and hydraulic properties, 3) wind erosion potential and soil and nutrient losses in runoff under simulated rain in select sloping fields, 4) soil C, nutrients, soil gas (CO2, CH4, and N2O) fluxes, and microbial biomass, and 5) the economics of CC grazing. We will closely work with the three producers who will: 1) participate in the planning and establishment of the experiment on their farm, 2) manage CCs, 3) participate in field data collection, 4) participate in field days, and 5) provide information for the economic analysis of costs and returns of CC grazing. The outcomes of this project will be a better understanding of the implications of cattle grazing or harvesting of CCs on soils and crop yields for different soil types and crop rotations. Information generated will assist farmers/ranchers with their CC management decisions. We will disseminate data through field days, conferences, social media, and journal articles. The field participants will evaluate the project success through surveys during field days. Overall, this project will contribute to the sustainable management of crop-livestock systems in Nebraska and surrounding states in the NC region.

The specific objectives of this interdisciplinary project are to assess: 1) grain yield, CC biomass, residual biomass post grazing/harvest, percent soil cover after grazing, and feed nutritive value, 2) soil structural, compaction, and hydraulic properties, 3) wind erosion potential and soil and nutrient losses in runoff under simulated rain in select sloping fields, 4) soil C, nutrients, soil gas flux (CO₂, CH₄, and N₂O) rates, and microbial biomass (Haney test), and 5) the economics (costs and returns) of CC grazing.

This project will inform farmers and researchers on the effects of cattle grazing or harvest of cover crops (CC) on crop production, soil productivity, and economics. Farmers and livestock producers will gain more knowledge of feed value as well as soil and crop production effects of CC grazing/harvest. Information from this project will assist farmers/ranchers with their decision making process. This project directly involves farmers and livestock producers because the experiment will be primarily conducted on producer’s fields. We will disseminate results through field days, social media, extension publications, peer-reviewed journal articles, and others.