Advantages and disadvantages on an organic corn crop from 25 tons of cattle manure per acre
In organic crop production, nutrients and weeds seem to be some of the larger expenses and challenges in maintaining a profitable farm. This project is designed to see if the use of 20 tons per acre of cattle manure on a 74-acre pivot farm in Hitchcock County Nebraska is more or less profitable than not manuring the soils in organic crop production. We will evaluate changes in yields and potential increased weed plant populations on the manured soils versus non-manured soils.
I soil sampled two 0-8” samples and two 8-36”samples mid October, 2010. Two manure samples were also taken in early December from the stock piled cattle manure to be spread on the field. About 25 ton of cattle manure was spread between November 29th and December 2nd, 2010 on 64 of the 74 acres under pivot irrigation on the Hardy Farm NW ¼ 22-3-34. Two unmanured strips 32 feet wide and about 800 feet long are in the middle of the pivot, and have about 25 tons cattle feedlot manure spread on either side and separating the two unmanured strips. The manure between the two unmanured strips is about 23 feet wide and is on the majority of the field, including the length of the unmanured strips. I used a Trimble handhelp GPS computer to record the lat/long coordinates of the unmanured strips, so these unmanured areas are easy to find after the manure is incorporated this coming Spring. The north unmanured Strip is between 40.21721580 degrees N 101.15326899 degrees W, 40.21744650 degrees N 101.15019818 degrees W, and 40.21713070 degrees N 101.15325287 degrees W, 40.21735740 degrees N 101.15017988 degrees W. The south unmanured Strip is between 40.21706340 degrees N 101.15324401 degrees W, 40.21730114 degrees N 101.15019240 degrees W, and 40.21697612 degrees N, 101.15323256 degrees W, and 40.21719774 degrees N, 101.15017138 degrees W.
The soil test results indicate 16 pounds of nitrogen in the 0-8” surface soil sample and 23 pounds of nitrogen in the 8-36” soil sample. Phosphorous 58 ppm M-P3, Potassium is 445, Sulfate is 31, Zinc is 1.51, Organic Matter is 2.7 and soil pH is 7.3.
The 2 stockpile cattle manure test ranged from 16 to 16.6 pound organic nitrogen per ton, 0.26 to 3.91 pounds ammonia per ton, and 0 to 0.72 pounds nitrate per ton.
Manure was not incorporated, but did have about 0.4” rain within a week of application. The color of the soil is darker from the manure laying on top of the soil and popcorn residue.
100 pounds of bin run wheat seed was drilled after popcorn harvest during the first week of October, 2010. The wheat was 2” tall during the manure application between November 29th and December 2nd.
WORK PLAN FOR 2011
We plan to disc the manure into the soil in April, ahead of planting popcorn. We will evaluate weed density and species in the manured and nonmanured areas of the research plot during the months of May and June. We will monitor the crop visually during the growing season. We will harvest the popcorn in the manured/nonmanured plot and record weight/yield totals and differences in the Fall of 2010. These results will then be reported to SARE.
We do not have information to share at this time, since the manure was applied a couple of weeks ago. The results of the research plot will be shared with Darwin Hinrichs with the NRCS office in Trenton, Nebraska and with Ron Seymour Extension Educator in Adams County, Nebraska, as well as with the UNL on farm research website.