Still time to get under cover

by on ‎09-14-2012 02:14 PM

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In a post-drought year, soil moisture management will take center stage for many farmers as they look ahead to the next season.


But in most any year, growers experience soil moisture shortages with annual short-term droughts, according to Harold van Es, a Cornell University crops and soils expert and author of the book, Building Soils for Better Crops.


“Most field crop farmers will experience drought in most years,” says van Es, took part in a recent soils research project funded by the Sustainable Agriculture Research and Education (SARE) program.


Research suggests it will be a good year to consider the value of soil organic matter, which is essential to soil water availability.


“You can change a soil’s pore size distribution and with that, you can change the water-holding capacity,” van Es says in the SARE report. “There’s more water available to plants when you a well-structure soil than if it’s compacted.”


Strategies for increasing organic matter are well known: applying manure or composts, seeding cover crops and reducing tillage are all effective.  Crop diversification is another approach.


Eileen Kladivko, a Purdue University agronomist who has studied cover crop mixes in corn and soybean rotations, says there’s a special need this year for increased applications of organic matter to help offset reduced crop residue.


“When there is poor crop yield, there may also be less crop residue (not necessarily, though, since I’ve seen corn fields that look great 'on the outside' but have poor grain yield)," Kladivko says.  "If there is less crop residue, then less organic matter being put back into the soil to feed the microorganisms, protect against erosion, and so on."


This summer she's been recommending fall-planted cover crops.


“Cover crops will help the farmer recoup part of the fertilizer N investment from this season, and will provide some benefits in improving soil organic matter and soil biological activity,” Kladivko says. In large parts of the country, including the Midwest, a cereal rye can be planted into early November, she says.


Once the cover crop option is past, other altrnatives would be to apply manure or other available materials. The extra organic matter will be "even more helpful than normal," she says.