Establishing Cover Crops at Time of Corn Planting: Determining Soil - Water Quality Benefits

Establishing Cover Crops at Time of Corn Planting: Determining Soil - Water Quality Benefits

Summary

Sixteen cover crop trials were planted in 2001, a very dry year. Four were at research institutions and 12 were on farms. Twelve of the locations had cover-cropped corn plots, which were comparable to the control plots. Two rainfall simulation projects were conducted to determine the effects of the cover crops on sediment and runoff phosphorus, with and without two rates of manure. Total runoff P was reduced by the cover crops. Three sites were used for field day tours, with over 200 attendees. National coverage of the project was covered in the No-Till Farmer Journal and the Conservation Technology Information Center newsletter. Two posters were presented at the ASA national meeting.

Objectives/Performance Targets

To investigate the establishment of cover crops at time of silage corn planting using herbicides to manage both the weeds and the cover crop; and,

To determine and quantify soil and water quality benefits.

Accomplishments/Milestones

In the 2001 growing season, 16 cover crop trials were planted, and of these four were at research institutions (Cornell Aurora Research Farm, USDA-NRCS Big Flats Plant Material Center (BFPMC), SUNY Cobleskill, and Cornell Animal Science T&R Center) and 12 were on farms. Six of the sites had multiple species. The species of cover crops looked at were red clover, white clover, alfalfa, birdsfoot trefoil, hairy vetch, and perennial and annual ryegrass. Four of the sites were replicated trials. The 2001 growing season was extremely dry and resulted in some problems with the herbicide Python adversely effecting some corn and cover-crop performance when used at the high end of the labeled rate. Out of the 16 sites this year, nine had cover crops that yielded as much corn as the control plots and had excellent cover, and three had excellent corn yields with only fair covers. Four sites were adversely effected by the cover crop due to drought, high seeding rates, and herbicide-weather interaction.

The trials that will be used for the soil quality experiment was initiated at both Cornell and BFPMC. Two simulated rainfall studies have been completed in Delaware County in the New York City watershed. One was conducted at Dave Post’s farm in May of 2001 and another was conducted in October of 2001 at Jim Lamport’s farm. At the BFPMC, we also evaluated five herbicide combinations with the above cover crop species, as well as mixtures of grasses and legumes. More than 500 farmers, agency personnel, and consultants had the opportunity to hear about this project through SWCD and Watershed Council newsletters and field tours.

Impacts and Contributions/Outcomes

Most of the farmers conducting cover crops trials this year seemed satisfied and seem interested in trying another plot next year. As a result of the outreach I already have more than 10 additional interested farmers in New York and several out-of-state agency personnel and farmers interested in conducting plantings.

Preliminary results from the rainfall simulation study reveal the following: Cover crops planted at the time of corn planting have the potential to reduce P loss from steeply sloped corn fields by (a) reducing erosion, therefore total P losses in runoff; (b) improving infiltration, thereby increasing rainfall required to generate runoff and reducing runoff volume; and (c) in the case of the leguminous cover crops, enabling lower rates of manure application by supplying N to subsequent crops (i.e, supporting P-based manure application rates).

Collaborators: