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.
PSWMRU contribution to the project has focused on the environment evaluation of manure injection as a component of the sustainable cropping system. Large plot-scale lysimeters, to monitor both nutrient runoff and leaching, were constructed for the evaluation of manure placement technologies. Lysimeter construction was completed in late spring 2011 and installation of instrumentation for automated water flow measurement was completed in early 2012. Ammonia and nitrous oxide (a potent greenhouse gas) emission measurements were made following broadcast application and shallow disk injection of dairy manure in spring 2011 and 2011. Injection reduced ammonia emission in both years by greater than 90% compared with broadcasting, however substantially greater nitrous oxide was emitted with injection during three week periods after application. A large reduction in ammonium-N losses in runoff with injection were observed after manure application in 2012, but extended dry periods in both years limited observation of impacts on nutrient leaching.