Department of Food, Agricultural and Biological Engineering

 


Articles Contributed to Ohio's Country Journal  
Mid-July 2005

 


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Applied Engineering

Building soil quality
Randall Reeder

  

If you want a farming system that protects water and air, and improves soil quality, it is hard to beat continuous no-till and cover crops.

And for situations where no-till yields have historically been low, we now have what you might call refinements to make no-till yields competitive. Refinements and improvements of the last few years include strip-till for corn, subsoilers that leave the surface residue in place, better herbicides, GPS and improved equipment.

Conservation tillage growth
Nationally, in 1990 conservation tillage accounted for 73 million acres of U.S. cropland, and 2004 it had grown to 112 million. No-till accounted for 17 million acres in 1990, and 62 million last year. So, out of a total of 277 million acres in cropland, the 62 million acres in no-till and 50 million acres in mulch-till and ridge-till have minimal concerns about erosion from water and wind.

So what does this mean to you? Less soil erosion, for one. If you're a farmer who has converted to conservation tillage in the past few years, you have several more tons of valuable topsoil per acre of land than you would have otherwise. Research shows that it's common to see a 95% to 99% reduction in soil erosion with no-till compared to conventional tillage in the Midwest and Southeast.

A prominent OSU professor, Rattan Lal, wrote a book on soil degradation. In it he said that between 1982 and 1997 we had an impressive reduction in soil erosion on U.S. cropland because of conservation tillage and the conversion of highly erodible land (HEL) to permanent cover. The total erosion on cropland decreased by more than 40% to 1.9 billion tons per year. If you're not a farmer that still looks like a whole lot of erosion. And it is. But it's about 1.3 billion tons less than without the improvements.

Keeping our soil in the field where it belongs builds soil quality. Keeping it out of streams, rivers and lakes improves water quality.

Ohio contributions to soil quality
Bill Richards, a Pickaway County no-till farmer, was named chief of the Soil Conservation Service about 15 years ago. And that's when the term "soil quality" gained prominence. I'm sure it had been around a long time, but it wasn't until this long-time no-till farmer became the head of SCS (now Natural Resources Conservation Service) that improving soil quality became a top priority for the federal government.

Today the USDA is in the midst of a critical assessment of conservation practices. I was invited to help out by researching and writing about practices related to soil management for non-irrigated cropland. Dale Westermann, a USDA-ARS scientist at Twin Falls, Idaho, is doing the same for irrigated cropland. by the time you read this is mid July, Dale and I will have blended our components into a sngle soiol management chapter. Other authors are writing chapters on water quality, nutrient management, and pest and weed  management.

Ohio has played a leading role in soil conservation research and will be prominently cited in our final draft. Some of the first research on no-till corn production was done by OARDC research scientists and engineers at Wooster starting about 1960. The USDA-ARS unit at Coshocton has a proud history in research and measurement of erosion on sloping cropland. Research at the Experiment Station at Hoytville in Wood County has shown farmers how to suceed with conservation tillage on poorly drained soil. (Step No. 1: Drain it)

As I read through stacks of research articles and books, the value of crop reside management practices stood out. Of course grass waterways, terraces and various types of vegetative barriers, both in a field and on the downslope edges, play a role in conservation. In the years from the Dust Bowl until no-till became "accessible" to the everyday farmer, those practices performed as well as could be expected. But when the cropland beside and above these conservation measures is all moldboard plowed there is a limit on how long they handle the load.

Summary
Based on all the previous research, our recommendations will include the following points. Continuous no-till, with cover crops where needed, provides the best overall environmental protection. The development of short season cover crops for northern climates can be important to reducing winter erosion, and minimizing the movement of nutrients to groundwater or surface water. Vegetative buffers can provide important environmental benefits, especially where conservation tillage practices are not quite adequate. Farming on the contour and using contour strip cropping are common sense practices. Continuing the practice of converting highly erodible land to forestry or other permanent cover is important.

There's more, but that gives you a quick, early glimpse of our results.

In case you're wondering, one of the goals of this assessment project is to help decide what conservation practices are emphasized in 2007 Farm Bill. I'll try to keep you posted in the "Ohio No-Till News" page in Ohio's Country Journal.

Randall Reeder, Associate Professor and Extension Agricultural Engineer, can be reached 614-292-6648 or reeder.1@osu.edu

This column is provided by the OSU Department of Food, Agricultural, and Biological Engineering.