Duration: 1992 - 1995
The application of dairy manure on cool season grasses is a common practice in Vermont, yet little is known concerning the utilization of manure nutrients in this situation. A three year trial was conducted on a dairy farm in Bakersfield, VT to evaluate the impact of semi-solid dairy manure plus fertilizer N on the yield, forage quality, and mineral uptake of a mixed grass sward as well as changes in soil test phosphorus (P) and potassium (K). The study site was a 25 year old stand of mixed grass species predominantly orchardgrass. Manure treatments consisted of a control (no manure) and semi-solid dairy manure as a single application after first cut (1X, 8 - 11 tons/acre/yr) or three applications per year (3X, 28 - 32 tons/acre/yr). Nitrogen (N) treatments consisted of ammonium nitrate at rates of 0, 45, 90, and 135 lb N/a in 1992 and 0, 60, 120, and 180 lb N/a in 1993, split evenly in 3 applications (early spring, after 1st cut, and after 2nd cut).
Yield was increased by both manure and N treatments and percent crude protein was increased by manure and N in 5 out of six cuttings. Our results suggest that a grass farmer could optimize returns over costs by combining manure applications and supplemental N. From this combination, the manure provides some N and all the P and K needs depending on the manure rate and P and K needs of the crop. Since much of the N in surface applied manure is lost due to volatilization, the fertilizer N on grass is important to optimize yields. In this study, the 3X manure application supplemented with 90 to 120 lb of N/acre/year gave the best return over treatment costs; however, this resulted in very high P loading, whereas the 1X manure treatment with 120 lbs of supplemental N gave only slightly lower returns and resulted in a balance of P applied to P removed from the crop.
See Optimizing Manure
and Nitrogen Fertilizer Applied to Grass Hay Crops for more detail
This site is maintained by Sid.Bosworth@uvm.edu, Plant & Soil Science Department, University of Vermont.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. University of Vermont Extension, Burlington, Vermont.University of Vermont Extension and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, sex, religion, age, disability, political beliefs, or marital or familial status
Last modified May 26 2004 12:55 PM