Crop residue: A valuable resource providing opportunities

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Farm Forum

Whether you’re a diversified beef or a crop only producer, my information should interest you. I have stated many times “One of my favorite times of the year is when cows are weaned and out grazing cornstalks.” At this time, cows are very content. They do not have a calf depending on them, nor are they dependent on humans. How do we further utilize this abundant and reasonably inexpensive resource, especially in Eastern SD? Cows are very efficient residue management machines, plus taste better than your tillage implement’s tires and shanks. The tillage equipment normally has multiple integrated tools with various purposes and likely cost over $15/acre/pass. (Iowa Farm Custom Rate Survey). A cow’s rumen, reticulum, omasum and abomasum can accomplish similar things to initiate residue breakdown over winter. You may have to think outside the traditional means of needing permanent fences with a well and being in your home section to graze. Of all the technology advances we’ve made in crop production, how about considering some things you maybe haven’t done before 1.) Portable electric fencing; 2.) Willingness to haul water; 3.) Approach a neighboring operator with the above concepts of residue management vs. asking as a benefit just for you. You may need to swallow pride and work with someone who may be leasing a parcel you once farmed. Being flexible, open minded and offering concessions is how businesses stay profitable. Can you devote a couple days to operate a grain cart or truck for them in return for a month’s feed? Some interesting data provided in a recent presentation by Warren Rusche, SDSU extension, showed comparisons made in a Nebraska study that indicated a slight increase in yield of the following year’s crop from grazing the stover (http://bit.ly/1Qt5UBZ).

Now, the mechanical harvest method. Four years ago I wrote an article on the subject of valuing corn stover. I “showed my work” with a bunch of possibly boring math. I’ll spare you that and share what I feel is the most reasonable value after a few hours of reading and calculations. In a common practice of simply raking behind the combine and baling mostly the leaves, husks, sheaths, shanks and cobs I’ve come up with the following removal and value using my local fertilizer prices. My hypothesis is in a 1,200-lb. bale at 15% moisture you have at most $10/bale in nutrient replacement value: $3.60N, $1.90P, $4.90K. Soil microbes require nitrogen to decompose stover and that can make the N immobilize. So by baling some stover, you may very well decrease the amount charged of the 9.6 lbs. of nitrogen estimated to be removed. The potassium value is quite variable as some estimates are based on the plant at physiological maturity (silage) vs. post grain harvest. By then more of the soluble potassium has leached out of the stover. Also, by harvesting the upper part of the plant and leaving much of the stalk, the concentrated portion of nutrients are left in the field as well as the ability to catch snow and prevent erosion. So if you half the N & K, that bale is at $6.15. References in this article are also from “Sustainable Corn Stover Harvest” by David Ertl, PH.D., Iowa Corn Promotion Board.

Stover removed from the field and returned as manure is another bartering tool. With fall winds, how much value do you suppose the leaves in the ditches provide the field? They might as well go through a cow’s abomasum and stay in the field. Livestock producers practiced sustainability prior to it being a buzz word. On the farms we work with, many topics are discussed in the full scheme of farm/ranch management. Science, math, accounting/analysis and nutrition are just a brief sample. You may contact us at 605-995-7196 or www.sdcfrm.com or myself at 605-770-0758, will.walter@mitchelltech.edu.