Conserving end-of-season N with effective seeding dates for cover crops based on fall growing degree days

View the project final report

• 2006 annual report
• 2007 annual report
• 2008 annual report

Commodities

• Agronomic: corn, rye
• Animal Products: dairy

Practices

• Animal Production: manure management
• Crop Production: continuous cropping, cover crops, nutrient cycling
• Education and Training: decision support system, demonstration, extension, on-farm/ranch research, participatory research
• Production Systems: general crop production

Most farmers and extension and UDSA-NRCS staff may know the appropriate date for seeding cover crops, but this is based on achieving 30% cover prior to winter for control of soil erosion. Our preliminary studies indicate that a planting date two or more weeks earlier is needed for effective N uptake. Our hypotheses are (i) that fall-winter losses of N leaching in corn fields are avoidable, and can be reduced or prevented if cover crops are used, and are planted early enough to be effective, and (ii) that use of cover crops and nutrient management has economic benefit to the farmer, can be integrated into the cropping system through outreach and education, and is transferable to other regions. All annual crop producers who apply and manage nutrients in diverse cropping systems will benefit, and directly 20 Massachusetts dairy/livestock farmers who are faced with increased costs of fertilizer associated with high petroleum prices. Objectives: i. Determine critical seeding dates and a growing degree day (GDD) model for rye cover crops. ii. Evaluate methodologies for early establishment of cover crops. iii. Demonstrate economic benefit of adopting “effective” cover crops.

Of 20 dairy/livestock farmers who participate in on-farm studies and farm based outreach in the project, 15 will use the developed assessment methods for cover crop effectiveness in recovering end-of-season nutrients, and 10 will make management decisions (changes) to ensure cover crops are effective for N uptake. The changes might include choosing shorter season corn hybrids, and management changes to ensure earlier spring planting, and thus earlier harvest, to enable timely cover crop planting in the fall.