Identification of Management Practices and Cultivars for Organic Hard-Winter Wheat Production
1. Identify existing hard winter cultivars that perform best in yield, test weight, competitive ability, and disease and insect resistance or tolerance under organic conditions.
2. Determine effectiveness and value of compost amendments and green manure in increasing yield and grain quality.
3. Determine the rate of mineralization and estimate number of years of benefit provided by compost addition.
4. Analyze the economic break-even points through enterprise budgeting for organic production with and without compost addition.
5. Determine end use quality of current cultivars and elite lines by mixograph, NIR and miller and baker evaluation.
Dairy manure compost was applied to dryland organic wheat production fields in Box Elder County, Utah. The production field is in crop-fallow rotation, so two sites (alternate years) were treated in the first two years. The compost was applied at zero (control) and 50 tons per acre in a split-plot arrangement with compost addition as whole plots with three reps and ten germplasm entries as split plots within the whole plots. The two years of data were combined in a single analysis that was a split-split plot design. Years and locations were confounded due to the nature of the crop-fallow rotation. Additionally, compost treatments of zero, ten, 25, and 75 tons per acre were examined as a randomized complete block design for the single cultivar Hansel (with 0 and 50 tons per acre) compost addition data for Hansel coming from the immediately adjacent split-plot experiment).
Yield trials and soil testing in the three years since the project began have shown that compost addition results in higher grain yields for winter wheat. The yield effect is not the same for all cultivars, and there is a significant genotype by environment interaction. The highest yielding wheat cultivar under no compost addition to date is Bonneville, a high-quality bread wheat released within the past three years by the University of Idaho. At a compost application rate of 50 tons per acre, the top yielding cultivar to date is a breeding line, UT1944-158, that has recently been increased in foundation seed and has been replanted in a foundation field on the land of one of our SARE collaborators. The Utah Agricultural Experiment Station has approved UT1944-158 for release under the name Golden Spike Wheat. Protein levels in the grain also increased as a result of the compost addition. The linear correlation for protein level was 0.70. Improvements in mixograph quality were also observed.
These cost assumptions and conclusions were made:
Average yield for non-organic wheat was assumed to be 28 bushels per acre. Compost would be purchased and trucked 50 miles (one way). Compost charges are based on cost figures from E.A. Miller’s. If a return load is found, the mileage cost is reduced to $1.25 per mile. Land costs are not included in economic calculations, and labor costs are included in machinery operating costs.
A two-dollar premium is given for the organic wheat.
General economic conclusions were the following: a) addition of compost is not profitable in the first crop year with any level of compost; b) the addition of ten tons of compost per year becomes economically viable during the second crop year, if wheat is $3.50 (non-organic price) per bushel or higher; c) 25 tons of compost per year becomes economically viable during the second crop year, if wheat is $5.50 per bushel (non-organic price); d) 50 tons of compost per acre will take three to five crop years to break even (assuming yields remain constant); and e) 75 tons of compost per acre takes four to seven crop years to break even (assuming yields remain constant).
Reduction of chemical fertilizer applications can save producers large amounts of money. However, organic production can only continue so long as it is profitable. Currently, thousands of acres of dryland organic wheat are being grown in Utah. The newly released cultivar, Golden Spike, was tested in this study and results of these experiments were used to justify its release. Organic growers will gain more value added to their crop by growing a hard white winter wheat.
Farmer Adoption and Direct Impact
Some organic growers have switch cultivars to take advantage of higher yield and or quality of cultivars such as Golden Spike. It is expected that this acreage will grow with increased seed availability.
Producers have been involved in growing foundation seed increases of the new wheat cultivar, Golden Spike, as a precursor to including it in their production regime. While no specific field days have focused solely on the organic production, results from these experiments have been disseminated at Utah Agricultural Experiment Station field days.
This summary was prepared by the project coordinator for the 2000 reporting cycle.