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By Roger Samson
Profiles of resource efficient farming systems (farming Forever will become a regular pan of our newsletter highlighting farmers who have made the change towards more sustainable lamming practices. Rather than concentrating on one part of their operation we will try to give you a systems approach to provide a better understanding on how it all fits together. Our first report will involve Mike Strohm of West Union, Illinois. He should be a worst case scenario for input abuse end soil degradation since he is cash cropping row crops on 500 acres. Instead he has made the conversion to a more resource efficient farming system which can provide high yields using low inputs).
Mike is not only conserving soil in his corn - soybean rotation, he's building it. At the same time he has also reduced his fertilizer, herbicide, tillage and seed costs.
Buckwheat, hairy vetch, and rye cover crops, no-till corn end soybeans, aeration cultivation, mow-killing, foliar feeding and allelopathy are all part of the innovative farming system developed by Mike. He has even patented a piece of equipment to help to make his system (of farming) produce yields of approximately 55 bu/acre in soybeans and 150 bu/acre corn in an average rainfall year. However as we all know, 1988 was not an average rainfall year.
Five years ago, plagued by compaction, high input costs, low commodity prices, and less than outstanding yields this farmer had to start making changes to survive. Today he has become one of the most innovative and best conservation farmers in the U.S. corn belt.
Mike's soybean production system starts with the use of an Aer-Way, a multi-purpose secondary tillage tool which consists of a single bar of rotating tines capable of penetrating 7-8" . Two passes with the Aer-way over corn stalks provide an un compacted seed bed covered with corn residue. The tines of the Aer-Way leave crop residue virtually undisturbed. Winter Rye is then seeded at 75 Ib/acre with a no-till drill. He applies 110 Ib/ acre of ammonium sulfate to decompose stalks and get the rye started. In mid-May when soybean planting begins the rye is shoulder high, headed out and pollinated. Eight or 15 inch rows of soybeans are no-till drilled into the standing rye at a relatively low population of 120,000 plants per acre to prevent lodging. Immediately after soybean planting the rye is killed by mulching with a flail-types talk shredder attached to a second tractor. The soybeans grow right through the 4. mulch which helps conserve moisture for the germinating seedlings.
In addition to reducing erosion, and improving soil structure the main function of the rye is to control weeds in three ways:
· By being left on the surface rather than incorporated the rye acts to suppress weeds by providing a ground cover.
- By giving off chemicals which prevent germination of seeds directly under the mulch, rye being allelopathic. The large seed soybean and deeper placement enable the plant to come right through the allelopathic layer under the rye)
- By lowering the soil nitrogen level as h is growing since this material is not incorporated and the weeds do not get the benefit of the nitrogen (An added benefit of the low nitrogen level is increased nodulation and nitrogen fixation by the soybean).
Rye regrowth - Mike has found that the earlier the beans are planted the more rye regrowth occurs. He has either used a grass herbicide such as Poast or Fusilade to control rye or has delayed planting. He is currently testing Ryeman and Aroostook rye to find a variety which be less subject to regrowth. (Starting this fall, REAP will be testing these and other allelopathic varieties to find one which is both tough on weeds and doesn't regrow).
Moisture Although in a normal spring rye conserves moisture with as 100% ground cover, it will use up available moisture in a dry spring. This year being a dry year the result was that some of Mike's bean fields to be ripped up because of poor germination. His other fields will yield only half of what could be expected in a normal year.
Nutrient tie-up - Micronutrient problems connected with the system have been experienced bygraduates tudent, Marie Therese Voutsinos of the University of Guelph. Her results found that rye ties up nutrients on low fertility sandy sites. Mike has begun experimenting with foliar sprays to offset the problem. This year he tested Maxicrop and Nutricrop. He prefers Maxi-crop, which is a seaweed product, and it contains the growth hormone cytokinin as well as micronutrients. Indications were that yields in this very dry season would be substantially increased by the use of foliar sprays.
After soybean harvest the Aer-Way is used again to loosen the soil prior to a no-till establishment of hairy vetch seeded with buckwheat as a nurse crop. The buckwheat releases phospho rus from the soil and helps to protect the hairy vetch throughout the winter. In the spring the vetch grows to a height of approximately 20. before being knocked down with two passes with the Aer-Way. Com is then no-till planted with a liquid starter fertilizer being row applied at planting. A light rate of atrazine and 2,4-D is applied to completely kill the vetch and improve weed control. Further weed control is provided by a conventional row crop cultivator as the hairy vetch residue breaks down rapidly.
When the com is approximately 6-16 inches in height, Mike removes compaction and aerates the soil under the growing corn with a no-till aerator. He designed and built the device himself to side-dress nitrogen, loosen the soil and put oxygen into the corn root zone with minimal disturbance of the soil surface. The hard faced knives on the aerator gently fracture and lift the soil to a depth of 11-14 inches. Wings 2 inches from the bottom of each knife help in lifting the soil and corn plants 2-4 inches before they settle back down. About 30 hp per knife is required for the operation or approximately 150 hp for a 5 row unit. On his compaction prone soil, Mike now finds his corn plants can get their roots through the hard pan to reach subsurface moisture. The hairy vetch and side dressed nitrogen have allowed him to cut his nitrogen rates considerably (only 60 Ib/acre). He feels the aerator reduces his nitrogen requirement since increased subsurface oxygen and bacterial action reduce denitrification. Seed costs have also been reduced by growing his own soybean, rye, hairy vetch and buckwheat. For seed, he plants his vetch and rye together in the fall. The rye prevents the vetch from lodging and makes combining easier. He then separates the two in his seed cleaning mill.
There are some promising signs that with time Mikes system is improving. His cation exchange capacity (which represents the nutrient holding capacity of a soil) has moved from an average of 8-10 to 10-13 within the last 4 years. Excluding erosion losses of .25 Vac/yr under the current practice of no-till into cover crops his system is accumulating 3.75 t/ac/yr of organic matter. Here is the breakdown:
Soil loss (tons/acre) on the Strohm farm using various management practices
|With terraces||Without terraces|
|No till with cover crops||0,25|
Copyright © 1988 REAP Canada
Reprinted with permission. All rights reserved.
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