Friday, September 21, 2012

No - Till Helps Captures Snow and Improve Water Distribution

This is almost an outbreak of common sense, but what is also clear is that wind loss is possibly far less than the simple retention of a stubble held boundary layer. Certainly the build up in the low points appears to lessen.

All this leads to a more uniformly and better watered field and represents one more compelling argument in favor of no till agriculture.

Add in the judicious application of tree friendly fence rows to prevent a build up of any significant surface winds and we soon optimize the capture of winter snows.

In time we will surely get this right and it is delightful to chronicle the ongoing effort to optimize agriculture methodology.

No-Till Farming Helps Capture Snow and Soil Water

by Ann Perry

Pullman WA (SPX) Sep 05, 2012

Wheat stubble left standing by no-till management helps generate a smoother snow cover, which boosts dryland crop productivity in the summer, according to new ARS research. Photo courtesy of ExactrixTM Global Systems.

A smooth blanket of snow in the winter can help boost dryland crop productivity in the summer, and no-till management is one way to ensure that blanket coverage, according to U.S. Department of Agriculture (USDA) research.

Agricultural Research Service (ARS) soil scientist David Huggins conducted studies to determine how standing crop residues affect snow accumulation and soil water levels across entire fields. ARS is USDA's chief intramural scientific research agency, and this work supports the USDA priority of responding to climate change.

Huggins, who works at the ARS Land Management and Water Conservation Research Unit in Pullman, Wash., carried out this investigation on two neighboring farms. Both farms have the hilly topography typical of the Palouse region in eastern Washington. But much of one farm has been under continuous no-till management since 1999, while the fields on the other farm were conventionally tilled.

For two years, snow depths, density and soil water storage were measured manually at hundreds of points across the fields on both farms. Residue height at data collection points was also measured on the no-till fields.

Huggins found that standing wheat residue on the no-till farm significantly increased the amount and uniformity of snow cover across the entire field. Snow depths on the no-till field ranged from 4 to 39 inches, with an average depth of 11 inches, while snow depths on the conventionally tilled field ranged from 0 to 56 inches, with an average depth of 8.5 inches.

The snow distribution pattern on the no-till farm made soil water distribution more uniform and increased soil water recharge rates there. The more uniform snow distribution under no-till was particularly apparent for ridge tops and steep south-facing slopes where there was typically 4 to 8 inches more snow than on conventionally tilled fields.

Huggins calculated that the greater storage of soil water in no-till systems could increase winter wheat yield potential by 13 bushels per acre on ridge tops, six bushels per acre on south facing slopes, and three bushels per acre in valleys. As a result, regional farmers could increase their winter wheat profits by an average of $30 per acre and as much as $54 per ridge-top acre.

Producers affected by the 2012 drought might also benefit from using no-till to increase the amount and uniformity of snow cover on their fields. This would increase soil water recharge rates and soil moisture storage, which would facilitate the return of drought-stricken fields to their former productivity.

Results from this work were published in 2011 in Transactions of the ASABE. Read more about this study in the August 2012 issue of Agricultural Research magazine.

Related Links

ARS Land Managementand Water Conservation Research Unit

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