Project Overview
Annual Reports
Commodities
- Agronomic: sorghum (milo), wheat
Practices
- Crop Production: cover crops, no-till, nutrient cycling, tissue analysis
- Education and Training: technical assistance, extension, farmer to farmer, networking, on-farm/ranch research, participatory research, study circle
- Farm Business Management: budgets/cost and returns, agricultural finance, whole farm planning
- Natural Resources/Environment: soil stabilization
- Pest Management: competition, economic threshold, field monitoring/scouting, mulches - killed, mulches - living
- Production Systems: transitioning to organic
- Soil Management: green manures, organic matter, soil analysis, nutrient mineralization, soil quality/health
- Sustainable Communities: partnerships
Abstract:
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 per 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 1 to 2 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 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.
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.
Introduction:
Two years of field data have been collected and analyzed with the farm trials. Poor growing conditions for the cover crop 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 quite a bit lower with cover crop as compared to without (20 bu per 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, contributing 72 lb/a N. The range was from a low of 22 lb/A, up to 164 lb/A N on one farm from vetch.
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.
Results from the Kansas State University station trials showed dry matter yields of 2165 tons/a and 2.99 tons/a were produced by hairy vetch planted in mid-September following winter wheat and terminated on April 25 and May 14, respectively. The corresponding potential N contribution was 147 lb/a and 188 lb/a for the succeeding sorghum crop. In a season- with ample rainfall, delayed vetch termination tended to result in higher sorghum leaf N levels and grain yields, but treatment differences were not always significant. The positive effect of the early and late termination dates of vetch on the yield of sorghum without fertilizer N was equivalent to about 70 lb/a and 89 lb/a of N. Sorghum yields after vetch averaged over N rates were 6 to 10 bu/a more than without a preceding cover crop.
In a tillage trial, hairy vetch planted in mid-September following winter wheat produced 2.05 tons of dry matter by the time it was terminated the following May. Vetch contained an average of 128 lb/a of nitrogen (N). Method of vetch termination (no-till vs disk) had no effect on grain sorghum flag-leaf N concentrations or on yields. Vetch significantly increased sorghum leaf N and also increased sorghum grain yield by nearly 22 bu/a in the absence of fertilizer N. The apparent N contribution to sorghum yield by the vetch was approximately 58 lb/a.
The KSU station trials with Austrian winter peas had fall ground cover ranged from 26 to 36 percent. Winter pea above ground biomass terminated May 16 was about one-half that of terminated June 4. Nitrogen credited to the cover crop ranged from 9.48 to 30.70 lb N/ac. The overall effect of the cover crop and N fertilizer on flag leaf and whole plant N and grain yield was not always significant or consistent. The first increment of fertilizer N had the greatest effect on leaf and whole plant N and grain yield. Under the June termination, approximately 30 lb/a N as fertilizer was needed to produce a comparable sorghum yield to the cover crop with no added N.
Project objectives:
1. A network of farmers will share ideas, practical experiences and research information on cover crop rotations.
2. A collaborative process will build research partnerships between farmers and Kansas State University researchers on the assessment of soil quality, crop productivity, soil water use, and economic profit with cover crops in a wheat-grain sorghum rotation.
3. An evaluative process will serve as a feedback loop into the continuing development of the partnership between farmers and researchers.