Project 1: Evaluating the Establishment of Cover Crops At Time Of Silage Corn Planting
Location: Dairy Farms in NY state
Contact: Paul Salon
Tel: 607-562-8404
E-mail: [email protected]

Project 2: Evaluating Cover Crops for the Control of Runoff P Losses
Location: Dairy Farms in NY state
Contact: Peter Kleinman
Tel: 607-562-8404
E-mail: [email protected]

Evaluating the Establishment of Cover Crops
At Time Of Silage Corn Planting

The establishment of cover crops at time of corn planting allows the use of conventional seeding equipment, allowing for uniform distribution and efficient use of seed, and planting the cover crop when soil moisture conditions are optimal.

Corn hybrids have been conventionally bred to be resistant to imazethapyr (Pursuit) herbicide. Pursuit is tolerated by many cover crop species and can be managed in a cover crop system. The establishment of cover crops at time of corn planting is now possible with the use of herbicides to regulate the growth of the cover crop to avoid competition with the corn crop.

The goal of the project is to set up demonstrations in watershed projects within NY and Pa. which already have networks of extension, NRCS, SWCD and research personnel from Cornell and ARS. These Watershed projects are the NYC watershed in Delaware Co., The Skaneateles Lake Watershed for Syracuse and the Upper Susquehanna River Coalition which covers both NY and Pa. Work has started using this system in these watersheds with extension, NRCS and SWCD involvement.
Research on the effects of several CC species on water quality (phosphorus and sediment) will be investigated by Dr. Peter Kleinman, using ARS rainfall simulators and water and soil analysis. Soil quality will be monitored for improvements by techniques developed by Dr. Harold van Es at Cornell. Research will be conducted at the USDA Big Flats Plant Materials Center looking at species effects, use of mixes, seeding rates and the use of alfalfa as a crop the second year. The use of alfalfa in the system, harvested for haylage or grazed will allow double cropping, improved soil quality and the removal of excess phosphorus.

Profile of a Typical Beneficiary

Profile #1
Bob is a 58 year old dairy farmer who has been farming for thirty-one years his son is active in the farming operation and is interested in continuing the operation in the future. His farm has been in the family for 2 generations. He has expanded the operation, and borrowed money to improve his equipment and infrastructure. They are milking 100 cows, producing their own forages including about 50 acres of corn silage yearly. He has limited land resources and pressure from second-home buyers has dramatically increased the cost of and availability of nearby land. 50% of his cropland is highly erodible. He is interested in improving and maintaining soil quality and reducing erosion and water quality off farm. He is interested in the appearance of his farm and his image as a responsible farmer interested in protecting the environment.

Profile #2
John is a District Conservationist in a field office with NRCS, he has 15 years of experience. He is in charge of writing conservation plans for farmers, which must meet criteria for soil erosion and nutrient management. Reducing the number of years of corn is not an option in this county since farmers can’t expand their land base due to rapid growth from development. Pressure from outside of the farming community is rising to reduce environmental effects from agriculture. Farmers are being required to comply with conservation plans in order to receive benefits from other USDA programs. A low cost method is being sought to achieve compliance.

Project Narrative

Silage corn has been identified by the USDA-NRCS as one of the most significant sources of soil erosion and agricultural related water quality problems in the Northeast. Silage corn does not leave enough crop residue to provide cover over the winter or allow for adequate cover necessary for the effective use of conservation tillage practices in the Spring. Runoff and leaching of fertilizer, manure and pesticides lead to water quality problems. These problems can be very costly to remedy and can lead to human health problems. Cover crops have long been used with row crops to reduce soil erosion, add organic matter and nitrogen, improve soil tilth, recycle nutrients, and for weed suppression. The use of cover crops specifically alfalfa is known to improve productivity by breaking up compacted soil layers caused by heavy farm equipment. A method is being developed to seed cover crops at time of corn planting (Salon and van der Grinten, 1999)

The establishment of cover crops immediately following the harvest of silage corn has been a problem due to the late harvest and short growing season in the Northeast. Aerial seeding of cereal rye and ryegrass during corn tasseling can be partially successful but is dependent on, adequate soil moisture and the degree of compaction and crusting of the soil surface. Interseeding cover crops, when the corn is 12-18 inches tall, after cultivation, and band application of herbicides is an option. This practice has had mixed results due to soil and weather conditions. Due to the limited use of cultivation and band spraying and a relatively narrow window of opportunity to cultivate and seed, this practice has not been widely accepted. An alternative establishment method needs to be developed which can be done efficiently and incorporated into existing operations using conventional equipment.

The establishment of cover crops during corn planting has been prevented by incompatibility with commonly used residual pre-emergence herbicides. Now with the use of post emergence, low volume imidazolinone, (IMI) herbicides such as Pursuit and conventionally bred corn hybrids resistant to them, this option is now possible. The establishment of cover crops at corn planting overcomes some of the barriers of previous cover crop establishment methods. The system enables the farmer to get the cover crop on early when there is good soil moisture conditions for establishment. The cover crops then benefit due to some early growth prior to corn canopy closure and for rapid growth following corn harvest. Cultivation is not required to prepare a seedbed. The cover crops can be established using conventional seeding equipment allowing for uniform distribution and efficient use of seed (lower seeding costs) resulting in better stands, or can be broadcast immediately following or during harrowing, or by conversion of insecticide boxes to drop seed at box level during planting operation. This method is designed to be uncomplicated and to fit into existing operating procedures. The cover crop stands that can be produced by this method is far superior to past methods so that actual soil improvement, soil erosion reduction and water quality benefits may be actualized.

With the use of certain herbicides labeled for both corn and alfalfa it would be possible to harvest the alfalfa the second year prior to corn planting (double cropping) or to leave it down for several years for subsequent harvests. This would reduce soil erosion, increase p uptake reduce energy requirements for field preparation, allowing herbicides and field preparation to be used for two crops instead of one.

The goal of the project is to get several years worth of on farm research trials and demonstrations located around the state of New York and Pa. which can be used to educate farmers on this technique. I will utilize the facilities at SUNY Cobleskill, Cornell T&R Center, and farms located in the New York City, Skaneateles Watershed projects and Upper Susquehanna River Coalition in NY and Pa.

The advantage of the approach is that: all of these locations are high profile which already receive and has the potential to publicize and disseminate the information obtained. These sites along with the USDA-NRCS Big Flats Plant Materials Center will insure a wide geographic distribution for varied soils and climate and to allow farmers access to visit these sites through existing and planned tours. The colleges will allow for student involvement, many of these students come form active dairy farms and will be able to try this technology on their own farms.

There are 2 components to this work; 1) Education, demonstration, outreach and promotion of this technique to educate farmers, and agency personnel. This will also give us the opportunity to evaluate the system on different soil types, microclimates, corn planting dates and farm operations.
2) Research to quantify the benefits of the cover crop system from a soil quality and water quality perspective as well as some agronomic considerations. This information will be used to promote the benefits of this cover crop system to beneficiaries.

Essential elements:

  • A Power Point presentation will be created to use at watershed and other farm meetings to expose farmers and conservation agency personnel to the concept of the cover crop system.
  • Utilize existing tours in these watershed areas to promote cover crop system.
  • Write article to be distributed to Watershed & SWCD newsletters.
  • Try to obtain permission to put demonstrations at the Empire Farm Days in N.Y. and Ag. Progress Days in Pa.
  • Write a 1-2 page guide to the given to farmers and conservation agency personnel interested in trying the CC system.
  • Economic analysis conducted to determine cost of the system.
    Intensity and duration: Approximately 6 hours per year will be needed with individual farmers, this does not include data collection which will be independent from outreach activities.

Discussion of this cover crop system with farmer cooperators who have tried the system came up with these research suggestions: try cover crop mixes, better weed control, vary cover crop seeding rates, different planting dates, vary corn population density, use of alfalfa the following year, effects on soil and water quality.

  • In order to quantify soil quality improvements larger plots of red clover, white clover, birdsfoot trefoil, alfalfa, and perennial ryegrass and a control will be established at the Big Flats Plant Materials Center and grown for 3 years. The soil quality will be evaluated the 1st and 3rd year for the following soil quality measurements: soil penetrability, using a penetrometer, steady state infiltration derived from Cornells rainfall simulator (Ogden et. al., 1997), sorptivity, measured as time to ponding from rainfall simulator, macroporosity, bulk density and organic matter. Corn yields and cover crop biomass will be monitored yearly. Completely randomized block design, with 3 replications.
  • There are presently 2 herbicides labeled for both corn and alfalfa, Pursuit and Buctril. Three application times will be investigated pre-emergence, early post and mid post and 2 seeding rates. Corn yields and 1st cutting alfalfa yields will be measured. Split plot design with seeding rates being main plot, with 4 replications per treatment.
  • In order to provide maximum flexibility in weed control and to provide better erosion control and nutrient uptake a mixture of cover crop species may be practical. Four seeding mixtures will be evaluated: a) 3 lbs/ac red clover, 3 lbs/ac birdsfoot trefoil and 4 lbs/ac of perennial ryegrass b) 3 lbs/ac red clover, 3 lbs/ac birdsfoot trefoil and 4 lbs/ac of annual ryegrass c) 3 lbs/ac red clover, 3 lbs/ac white clover, and 4 lbs/ac of perennial ryegrass d) 3 lbs/ac red clover, 3 lbs/ac white clover, and 4 lbs/ac of annual ryegrass. These will be compared to the species sown alone. Corn yields and cover crop % cover will be evaluated. Complete randomized block design with 4 replications.

To assess the potential water quality benefits of cover crops, runoff experiments will be conducted at two field locations by the USDA-ARS. At the Dave Post and Jim Lamport farms in the Town Brook watershed, part of the New York City Watershed Agricultural Program; and, the FD-36 Watershed, at USDA’s ARS Klingerstown Watershed Field Station in the Susquehanna River Watershed in Pennsylvannia. Three cover crops (white clover, red clover and perennial ryegrass will be established on Lackawanna (coarse-loam, mixed, active, mesic Typic Fragiudept) and Berks (loamy-skeketal, mixed, active, mesic Typic Dystrudept) soils with roughly 5% slopes. Two split-plot, 1 x 2m runoff boxes will be installed within the control and each of the cover crops at the sites. locations. Three, 30 min runoff events will be generated on three consecutive days using a Miller rainfall simulator (Fig. 1), following guidelines laid out by the National P Project (Sharpley et al., 1999). One week after the initial rainfall simulations, manure from local sources (dairy in Town Brook Watershed, swine in FD-36 Watershed) will be surface applied to plots at rates of 50 and 100 kg P/ha. Rainfall simulations will be repeated to generate 3, 30-min runoff events on three consecutive days, then repeated weekly until loses of total P are equivalent to those obtained from the boxes prior to manure application. Anticipated logarithmic declines in runoff P concentrations will be compared between cover crop treatments and controls, and results will be presented for incorporation into the P Index, a site assessment tool aimed at improving agricultural P management.

Key Individuals

The project leader is Dr. Paul Salon. He has thirteen years of experience working on cover crop research with corn silage at the USDA-NRCS Big Flats Plant Materials Center. He has worked as project leader on a SARE grant # LNE97-96. Eastern Gamagrass: Determining its Feasibility as a Forage Crop in the Northeast, which will be completed 3/31/00. He has experience working with farmers, agency personnel and other research scientists with cover crops.

Dr. Harold van Es will be consulting with us on the design of the soil quality investigation making available his equipment and training personnel in its proper use. He has worked at Cornell University as a professor for twelve years with research and extension responsibilities in soil and water management.

Dr. Peter Kleinman will be consulting on the water quality investigation auiding and conducting runoff experiments and overseeing extrapolation of results to state and federal agencies charged with P Index development.

Dr. Nate Hartwig will be consulting on weed control issues. He has over 30 years experience as weed scientist at Pennsylvania State University and has 15 years of experience working on a living mulch cover crop system.

Dale Gates, Resource Conservationist USDA-NRCS in the Skaneateles Lake Watershed project. Masters Degree and 10 years experience with NRCS. Works with farmers developing comprehensive nutrient management plans. Will assist in farmer recruitment and promotion of system.

Matt Thornton, Extension agent working on education program in the Skaneateles Lake Watershed. Masters degree in Agriculture with 3 years of extension experience. He will work with farmers in recruitment and developing educational material for project as well as assist in data collection. Has been involved working with farmers on two plantings in the last two years.

Rick Weidenbach, Delaware Co. District Manager, 20 years of experience working in the county and the NYC watershed with farmers on soil conservation practices. He will be responsible for recruitment, education and managing disbursement of moneys to farmers for entire project.
Dale Dewing, Agronomy specialist with Cornell Cooperative Extension works as nutrient management planner. He has fourteen years of extension experience in New York. He has a masters degree in Agronomy. He will be responsible for recruitment, education and assist in data collection.

Mark Schmidt, Biological technician USDA-NRCS he will be responsible for assisting farmers and other research stations in establishing cover crops. Mark is a dairy farmer with 10 years of experience he has worked for NRCS part time for three years assisting in on farm eastern gamagrass trials. He has established two fields of this cover crop on his farm and assisted at Cobleskill and Morrisville plantings.


1) Approximately 500 farmers will be informed of the project via meetings with Watershed Ag. Councils and newsletters and personal contacts by agency personnel knowing of those farmers who may be interested in cover cropping. Of these 50 will provide interest in participating. These farmers will be classified to the degree in which they will need assistance and degree of interest.

2) A group of 10 will be selected with the greatest chance for success. Assistance will be provided to select location, cover crop and weed control options. The plantings will be monitored to determine if any problems arise to document problem. Yields for the corn, percent cover of the cover crops and weeds will be measured in the fall, and cc biomass in the Spring.

3) A training session will be held for agency personnel who may be interested in helping with data collection since it will be difficult for all farms to have there corn yields measured at the same time and it will take cooperation. This will result in commitment from 6 agency people to assist in collecting yield data on the farms in their area.

4) A report on these 10 sites will be written and distributed to all collaborators, beneficiaries and those farmers expressing initial interest to maintain ownership and interest in the project.

5) Research plot locations, soil tests and detailed protocols will be developed for Big Fats PMC. Cobleskill and Cornell which will be peer reviewed. Conduct research, prepare yearly report to be sent to cooperators and beneficiaries. This will inform beneficiaries of the project, maintain their interest and ownership of part of a larger project to support them in continuing with the cover crop system on their farm. Final reports on water quality and soil quality benefits will be of interest to agency personnel both locally and at the state and national level. If significant improvements are seen an initiative may be started at a higher level promoting cover cropping.

6) The second and third year groups of 10 farmers will be targeted to be introduced to the system and the first groups of 10 will be followed up with to see if they are continuing with another planting and to determine reasons if they are not.

Literature Review

The establishment of red clover, alfalfa, birdsfoot trefoil and perennial ryegrass has been conducted at time of corn planting since 1996 at the Big Flats Plant Materials Center without significant corn yield reductions using conventional and IMI corn hybrids (Salon and van der Grinten, 1999 ). The biggest issue is weed control. The establishment of crown vetch and birdsfoot trefoil using IMI corn hybrids has been successfully demonstrated by Hartwig(1993 ). Hartwig (1998) found that seeding alfalfa into IMI corn using Pursuit for weed control is possible but the alfalfa seedlings suffer too much from corn competition. At Cobleskill Ag. & Tech. observations in 1999 from at a field trial showed that in a dry year at high alfalfa planting density corn can be out competed by the alfalfa. Therefore by varying the rate of alfalfa and the corn and including buctril in the herbicide mix it should be possible to establish a stand for a short alfalfa rotation or grazing.

For legume cover crops to be considered an effective N source for corn, they must supply sufficient N and there must be a synchrony between legume N and corn demand. Stute and Posner (1995) found in a study in which the legumes where established the previous year, that with red clover and hairy vetch residues decompose rapidly, releasing half of their N within 4 weeks after burial, while very little was released after 10 weeks. Mean corn grain yields following legumes were similar to those produced with 179 kg N/ha, indicating that in addition to release in N in synchrony with the uptake pattern of corn, legumes released N in adequate amount for corn production. In the cover crop system being proposed in this grant the cover crops are well established by 5/15 of the corn planting year producing around 500 kg of foliar dry matter, it is anticipated that additional sources of nitrogen will be required. Legume cover crops have proven to supply adequate N for corn growth in the Northern USA when seeded the year prior to corn (Bruulsema and Christie, 1987).

Cover crops generally increase the rate and amount of infiltration from rainfall. They prevent surface sealing by intercepting rainfall. Cover crops increase available water storage capacity due to increase in transpiration, this reduces percolation and leaching losses and leaves more capacity in the soil for infiltration of subsequent rains and reduction of runoff and erosion. Cover crops increase soil macroporosity both directly through root growth and indirectly by inmproving the habitat and activity of mesofauna that in turn create macroporosity. The presence of cover crops can increase the hydrologic resistance of the soil surface which slows down runoff reducing peak runoff rates off site affects. Soil erosion is reduced due to reduced impacts slower velocity of water and the addition of organic matter adding to aggregate stability (Dabney, 1998).
Perennial crops commonly have active root growth early in the growing season and can reach into compacted layers when they are still wet and relatively soft. Crops with deep tap roots such as alfalfa can penetrate into compacted subsoil (Magdoff and van Es, 2000).

In 1991 a review was conducted about cover crops in Corn, in Canada issue of Agribook. Bob Sheard of Dept. of Land Resource Science at University of Guelph reported on a 6 year study with red clover. Red clover was best established between corn emergence and 3rd leaf stage. They found no corn yield reductions with the cover crops and a reduction in fertilizer needs from 138 kg N/ha to 95 kg N/ha. They found improvements in silage quality of .5-1.0% CP. They found a reduction in runoff of 45% in Fall and early Spring and 87% after Spring plowing and planting. There was a sediment reduction from 48% in Fall and early Spring to 75% after corn planting in the Spring.

A recent study by Robertson et al. (2000) looking at greenhouse gas emissions reported when taking into consideration soil C, N fertilizer, Lime, fuel, N20 and CH-4 there was an overall decrease in greenhouse warming potential of 45% over conventional tillage in a low input system with legume cover.


Bruulsema, T.W., and B.R. Christie. 1987. Nitrogen contribution to succeeding corn from alfalfa and red clover. Agron. J. 79:96-100.

Dabney S.M. 1998. Cover crop impacts on watershed hydrology. Soil and Water Cons. 53(3) 207-213.

Hartwig, N.L. 1993. Establishment of crownvetch and birdsfoot trefoil cover crops in field corn. Proc. Northeastern Weed Sci. Soc. 47:74-75.

Hartwig, N.L. 1993. Establishment of crownvetch and birdsfoot trefoil cover crops in field corn. Proc. Northeastern Weed Sci. Soc. 47:74-75.

Ogden, C.B., H.M van Es, and R.R. Schinekbeck. 1997. A simple rainfall simulator for measurement of soil infiltration and runoff. Soil Sci. Soc. Am. J. 61:1041-1043.

Robertson, G.P. Eldor A.P. and R.R, Harwood. 2000. Greenhouse gases in intensive agriculture: contributions of individual gases to the radiative forcing of the atmosphere. Science.289:1922-1925.

Rodale Institute. 2000. Building Soils for Better Crops 2nd ed, Magdoff F. and H. van Es. Sustainable Agriculture Publications, USDA, Washington D.C.,230pp.

Salon P..R. and m. van der Grinten. 1999. Cover crop establishment at corn planting using conventional and IMI corn hybrids, NE ASA Meeting, Agron. Abstract. p.39.

Sharpley, A., T. Daniel, B. Wright, P. Kleinman, T.Sobecki, R. Parry and B. Joern. 1999. National research project to identify sources of agricultural phosphorus loss. Better Crops 83:12-14.

Stute, J.K., and J.L. Posner. 1995. Synchrony between legume nitrogen release and corn demand in the upper midwest. Agron. J. 1063-1069.

Dr. Peter Kleinman, USDA-ARS Pasture and Watershed Lab Pa. State
(814) 865-3184 [email protected]

Dr. Harold van Es, Professor Cornell Extension soil and water mangement
(607) 255-5629 [email protected]

Dr. Doug Goodale, Chairman of agriculture division and Professor of Agronomy
(518) 255-5323 [email protected]

Dr. Nate Hartwig, Professor of weed science, at Pa. State
(814) 865-1906 [email protected]

Matt Thornton, Extension educator Skaneateles Lake Watershed
(315) 677-4630

Fred Gaffney, New York State Agronomist USDA-NRCS
(315) 4776530 [email protected]