Intensifying Cropping Systems in Semi-Arid Environments to Enhance Soil Health and Profitability

View the project final report

• 2016 annual report

Commodities

• Agronomic: canola, hay, peas (field, cowpeas), wheat
• Vegetables: peas (culinary)
• Animals: bovine

Practices

• Crop Production: catch crops, cover crops, no-till, nutrient cycling
• Education and Training: demonstration, on-farm/ranch research
• Farm Business Management: budgets/cost and returns, risk management
• Natural Resources/Environment: carbon sequestration
• Production Systems: general crop production
• Soil Management: soil microbiology, organic matter

Soil health has received increasing interest in recent years and cover cropping has been a management tool encouraged to expedite recovery of soil function in degraded cropping systems. However, adoption of soil health promoting practices such as cover crops has been hindered in water-limited environments due to potential depletion of soil water resources and subsequent decline in cash crop yields. Some producers have questioned the feasibility of using double crops instead of cover crops, as double crops could provide an economic return. Our main objective was to evaluate cover crop and double crop options in continuous wheat systems within the water-limited environment of the Texas Rolling Plains. Four study locations in the Texas Rolling Plains were utilized, of which three were conducted on-farm. We hypothesized that double crops could provide similar benefits of cover crops with an opportunity for additional profit. We comparing traditional wheat cropping systems (summer fallow) with rotational options (canola), cover crop options (mixed cover crop species at two different rates and termination timings), and double crop options (mungbeans, cowpeas, pigeon peas, and guar). Success of summer cropping programs varied by location. Two of four locations endured at least on failure of summer crops due to drought conditions. In addition, the wheat crop also failed at two locations due to persisting drought conditions. During one of three summers, guar and mungbean were shown to produce a viable grain crop without hindering subsequent wheat yields. At some locations, the double crop provided the greatest economic return as the subsequent wheat crop (fallow or summer crop) failed due to lack of fall moisture and stand establishment. Across all on-farm locations, wheat yield or forage production was not statistically different among treatments. If adequate fall precipitation was recorded, stored soil water did not differ among treatments at time of wheat planting as soil water deficit due to summer crop use was recovered with enhanced soil water capture and storage. Microbial analysis of soil using PLFA did not show any significant effect due to treatment during the project, which may be a result of lack of short-term effects on sites that had a long history of good no-till management. In-season precipitation proved most critical in success of crop growth, rather cover crop, double crop, or the wheat cash crop. The cost of the cover crops would be difficult to recover, as net returns of traditional wheat systems are in the region are marginal. Cost share programs could offset such costs, but crop insurance is not currently available in the region when systems are intensified using double crops. Integrating cattle to utilize summer forage could potentially offset costs and enhance soil health, which warrants future research and demonstration. 

Objectives

1. Evaluate the effect of intensified cropping systems in a predominantly monoculture wheat producing region that will promote soil health and water conservation while maintaining agronomic profitability and environmental sustainability; and

2. Determine and disseminate the most effective best management systems that promote economic profitability and environmental sustainability while protecting natural resources.

Performance Targets

1) Identify and meet with on-farm collaborators; 2) select on-farm demonstration sites; 3) select treatments for each location; 4) establish cover crop and double crop treatments; 5) measure initial soil parameters; 6) measure soil moisture storage; 7) establish cash crop wheat crops.