One thing growers in the High Plains have known for a decades is that no-till, summer fallow stores water. But to store water you have to keep the weeds away and you either control them with tillage or herbicides.
A recent ARS New Service story says that an inch of water in an acre of soil is worth $25 to $30 per acre in lost yields. And in an area that sees only 8, 12 or 16 inches, each additional inch is worth a lot of value
Soil scientist Merle Vigil at the USDA’s Central Great Plains Research Station at Akron, Colo., who calculated this value explains that 4 to 6 six tillage passes over a 14 month fallow period results in an evaporative loss of 3 acre-inches of water and a cost $24 to $48 per acre in fuel and labor costs.
He emphasized this costs growers $99 to $138 an acre in lost water and tillage expenses. However he never put a value on the cost of herbicides and spraying to keep the field weed free during the fallow period. And two passes with glyphosate and spraying would be about $15 per acre bare bone minimum.
These scientists at Akron have rediscovered that farmers can prevent much of that loss and store more precipitation by eliminating tillage and adopting no-till and other crops in the rotation.
The report states says that by combining no-till with crop rotation management, farmers could capture more of the 14 to 18 inches of annual rain or snowmelt they receive.
And the most profitable rotation is no-till wheat one year and no-till millet the next with a fallow overwintering period between the wheat harvest and planting millet and could increase net income by $1,300 a year compared to a no-till wheat-fallow rotation.
To read more link to http://www.ars.usda.gov/