Farmer-to-Farmer Cover Crop Network Complementing On-Farm and On-Station Trials

1995 Annual Report for LNC95-083

Project Type: Research and Education
Funds awarded in 1995: $46,954.00
Projected End Date: 12/31/1997
Matching Non-Federal Funds: $65,378.00
Region: North Central
State: Kansas
Project Coordinator:
Jerry Jost
Kansas Rural Center

Farmer-to-Farmer Cover Crop Network Complementing On-Farm and On-Station Trials


A network of farmers and researchers shared ideas, practical experiences and research information on cover crop rotations. A collaborative process established partnerships between farmers and Kansas State University (KSU) researchers on the assessment of crop productivity, soil quality, nitrogen fixation, soil water use, yield risk and economic returns with cover crops in a wheat/grain sorghum rotation. Ten farmers across two farmer clusters conducted cover crop trials on their farms with narrow, farm-scale plots. Two KSU Experiment Stations conducted complementary research. Joint visits on farms and stations gave practical assessments of the research partnership. Outreach included field days, written articles, and educational workshops.

The farmer-to-farmer cover crop network developed a better understanding of research and management guidelines on cover crops in a wheat to grain sorghum rotation. Consistent cover crop stands and weed competition emerged as a priority management concern along with soil moisture conservation.

The poor growing conditions in the fall and winter of 1995-1996 resulted in poor stand establishment of both cover crops on most farm sites. The average biomass of cover crops prior to spring tillage was less than half a ton, and the nitrogen contribution from the cover crop biomass ranged from only 2 lb/a to 71 lb/a. The resulting sorghum yields in 1996 were lower with cover crop as compared to without (20 bu/acre lower), though leaf tissue N status showed adequate levels in both treatments. Soil water measurements during the growing season indicated lower soil moisture in the cover crop plots, perhaps because of spring depletion prior to when the cover crop was destroyed.

Cover crop establishment was much better in the fall and winter of 1996-1997, resulting in an average of over a ton of cover crop above ground biomass. The range was from a low of 22 lb/a, up to 164 lb/a N from vetch. On the two farms with both cover crops planted side-by-side, the vetch produced more biomass and N than the pea.

Subsequent sorghum yields were higher in the cover crop plots in 1997 as compared to 1996, and were not significantly different than the fertilized control plots. Leaf tissue N also indicated adequate nitrogen status in both treatments. Soil water measurements in 1997 also were not different between plots. Observations by the farmer participants indicate that the timing of N release seems to be different from the cover crop as compared to fertilizer, and in some cases the sorghum plots following cover crops did not get dark green until fairly late in the season.

Hairy vetch at the KSU station trials provided excellent fall ground cover to provide protection from soil erosion. The average potential amount of N to be mineralized for use by the sorghum crop was 147 lb/a and 188 lb/a. In sorghum following vetch, leaf N did not increase meaningfully above an N rate of 30 lb/a. Sorghum following vetch required one to two days less time to reach half bloom than sorghum without a preceding cover crop. Averaged over N rates, sorghum yields were 6 to 10 bu/a more after vetch than where no cover crop had been grown. Highest yields were attained with an N rate of 90 lb/a in sorghum without prior vetch and with 30 lb/a of N in sorghum following vetch. The positive effect of vetch on the yield of sorghum without fertilizer N was equivalent to between 70 lb/a and 89 lb/a of N relative to termination date. A small, but significant increase in the number of heads per plant accounted for most of the treatment effects on yield.

Austrian Winter pea cover crop trials at the KSU station resulted in nitrogen credited to the cover crop up to 30 lb N/a. As with other N rate studies on the South Central Field, the first increment of fertilizer N had the greatest effect on leaf and whole plant N and grain yield.

North Central Region SARE 1998 Annual Report.


Rhonda Janke

KS State Univ.
KS 66506