1a.Objectives (from AD-416)
This proposal evaluates agronomic and environmental costs and benefits of a northeastern dairy farming system that is designed to be in balance with regard to energy and nutrient imports/exports. We evaluate the benefits and costs of alternative cover crops, manure application systems and energy production systems. Results are intended to serve as the basis for advancing northeastern dairy farming systems to greater productivity and resource independence.
1b.Approach (from AD-416)
An integrated farming systems model will be used to devise cropping systems based upon manure nutrients that will then be tested under different management scenarios in the field, tracking nutrient and energy flows as well as other production related factors. A demonstration/research site will be developed near University Park, PA, to establish field plots where alternative cropping systems are tested. Systems include corn and soybean rotations with various cover crops and winter small grains, including, but not limited to, canola to generate vegetable oil for farm machinery. In addition to tracking agronomic performance, pests and soil fertility, environmental variables will be measured (water and air quality). Optimal management combinations will be determined, from which agronomic recommendations will be developed.
Completed construction of 12 large (50 x 90’) field lysimeters at Rock Springs, PA and hired a graduate student to oversee lysimeter research. Measurements after dairy manure application showed that while manure incorporation with injection or aeration reduced ammonia volatilization by 44-98% relative to conventional broadcast application, manure injection periodically increased nitrous oxide emissions. Although nitrous oxide emissions were generally similar between manure application methods, on one sampling date nitrous oxide emissions from soils where manure had been injected were 433% greater than from soils where manure was broadcast.