This is almost an outbreak of common sense, but what is also clear isthat wind loss is possibly far less than the simple retention of astubble held boundary layer. Certainly the build up in the lowpoints appears to lessen.
All this leads to a more uniformly and better watered field andrepresents one more compelling argument in favor of no tillagriculture.
Add in the judicious application of tree friendly fence rows toprevent a build up of any significant surface winds and we soonoptimize the capture of winter snows.
In time we will surely get this right and it is delightful tochronicle the ongoing effort to optimize agriculture methodology.
No-Till FarmingHelps Capture Snow and Soil Water
by Ann Perry
Pullman WA (SPX)Sep 05, 2012
Wheat stubble leftstanding by no-till management helps generate a smoother snow cover,which boosts dryland crop productivity in the summer, according tonew ARS research. Photo courtesy of ExactrixTM Global Systems.
http://www.seeddaily.com/reports/No_Till_Farming_Helps_Capture_Snow_and_Soil_Water_999.html
A smooth blanket ofsnow in the winter can help boost dryland crop productivity in thesummer, and no-till management is one way to ensure that blanketcoverage, according to U.S. Department of Agriculture (USDA)research.
Agricultural Research Service(ARS) soil scientist David Huggins conducted studies to determine howstanding crop residues affect snow accumulation and soil water levelsacross entire fields. ARS is USDA's chief intramural scientificresearch agency, and this work supports the USDA priority ofresponding to climate change.
Huggins, who works atthe ARS Land Management and Water Conservation Research Unit inPullman, Wash., carried out this investigation on two neighboringfarms. Both farms have the hilly topography typical of the Palouseregion in eastern Washington. But much of one farm has been undercontinuous no-till management since 1999, while the fields on theother farm were conventionally tilled.
Fortwo years, snow depths, density and soil water storagewere measured manually at hundreds of points across the fields onboth farms. Residue height at data collection points was alsomeasured on the no-till fields.
Huggins found thatstanding wheat residue on the no-till farm significantly increasedthe amount and uniformity of snow cover across the entire field. Snowdepths on the no-till field ranged from 4 to 39 inches, with anaverage depth of 11 inches, while snow depths on the conventionallytilled field ranged from 0 to 56 inches, with an average depth of 8.5inches.
The snow distributionpattern on the no-till farm made soil water distribution more uniformand increased soil water recharge rates there. The more uniform snowdistribution under no-till was particularly apparent for ridge topsand steep south-facing slopes where there was typically 4 to 8 inchesmore snow than on conventionally tilled fields.
Hugginscalculated that the greater storage of soil water in no-till systemscould increase winter wheat yield potential by 13bushels per acre on ridge tops, six bushels per acre on south facingslopes, and three bushels per acre in valleys. As a result, regionalfarmers could increase their winter wheat profits by an average of$30 per acre and as much as $54 per ridge-top acre.
Producersaffected by the 2012 drought might also benefit from using no-till toincrease the amount and uniformity of snow cover on their fields.This would increase soil water recharge ratesand soil moisture storage, which would facilitate thereturn of drought-stricken fields to their former productivity.
Results from this workwere published in 2011 in Transactions of the ASABE. Read moreabout this study in the August 2012 issue of AgriculturalResearch magazine.
Related Links
ARS LandManagementand Water Conservation Research Unit
Hiç yorum yok:
Yorum Gönder