CEREAL RYE AND MANURE MANAGEMENT TO INCREASE NUTRIENT UTILIZATION IN PENNSYLVANIA DAIRY FARMS
Open Access
- Author:
- Binder, Jonathan Michael
- Graduate Program:
- Agronomy
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 11, 2019
- Committee Members:
- Heather Karsten, Thesis Advisor/Co-Advisor
Doug Beegle, Committee Member
Curt Dell, Committee Member - Keywords:
- double crop
cereal rye
dairy
manure injection
cover crop - Abstract:
- Dairy manure originating from farms within central Pennsylvania are a source of concern as manure nutrients lost to the environment threaten the health of the economically and culturally significant Chesapeake Bay. Double-cropping cereal rye (Secale cereale L.) after corn silage provides an opportunity to increase manure nutrient use and farm forage production, potentially beneficial both for farmers and the environment. Injecting manure into the soil may also decrease manure nutrient losses to the environment, conserving nutrients on the farm to be utilized for production. Prioritizing rye planting ahead of manure application in the fall allows it to take full advantage of warm weather and days with more sunlight and may increase N and P use and retention. In the first experiment, a randomized, complete-block, full-factorial experiment was conducted over two years to quantify the effects of i.) cereal rye management (cover crop vs. double-crop), (ii) fall-applied liquid dairy (Bos taurus L.) manure application method (broadcast vs. inject), and (iii) field operation priority system (priority) (manure priority vs. rye priority) on rye biomass, rye apparent manure-N and P recovery, subsequent corn silage yield, and total forage production. We found that the rye double-crop increased N and P recovery and increased total forage production by between 11 and 45% for broadcast manure and between 27 and 56% for injected manure. Prioritizing rye planting increased rye biomass, rye N recovery, corn silage, and total forage production because of increased rye biomass and nutrient retention. Injecting manure increased manure N recovery in most treatment comparisons, but increased recovery more when manure was applied first, early in the fall. There was also evidence that prioritizing rye planting and injecting manure with a double-crop increased P recovery. In the second experiment, a randomized, complete-block design experiment comparing N and P losses through waterflow from a cover cropping system and a double cropping system was conducted for two years on 12 hydrologically-isolated field-scale lysimeters that were constructed to measure volume and take subsamples of surface and subsurface flow. Concentrations of N and particulate and dissolved P were measured from samples taken at flow events. Concentrations of N and P were multiplied by surface and subsurface flows counted with tipping buckets to calculate mass load loss of N and P at each flow event from both surface and subsurface flow. Dairy manure was broadcast in both the fall and the spring to simulate a farm with excess manure. Treatments were a cover crop system with rye terminated in the spring and a double crop system where rye received 112 kg N ha-1 in the form of urea at topdress in the spring and harvested for rye silage in the spring. Averaged over two years, managing rye as a double crop increased rye biomass by 51%, rye applied N recovery by 31% and rye applied P recovery by 47% compared to rye managed as a cover crop. Subsequent corn yields were not different due to rye management in either year, but managing rye as a double crop increased total forage production by 22% compared to rye managed as a cover crop averaged over two years. Only the first year of nutrient loss through water flow could be analyzed. Annual nutrient losses from the two systems were not different over this first year, but temporal differences did exist. Although nutrient losses were small, the greatest reduction in loss was a 0.6 kg N ha-1 reduction in subsurface losses due to double cropped rye in the spring following cover crop termination and double crop harvest and before spring manure application.