NMSU branding

New Mexico State University

New Mexico State University

News Center

Conservative Tilling Means More Soil Nutrients for Eastern N.M. Farmland

LAS CRUCES - As farmers in eastern New Mexico switch to more conservative tilling systems like stubble mulch and no-till, reserves of important nutrients increase in the soil, said a New Mexico State University soil scientist.

"Particularly on the eastern side of New Mexico, farmers are switching to more conservative methods of tillage," said Bill Lindemann with NMSU's Agricultural Experiment Station. "The advantages of these systems are manifold, including decreasing soil erosion and conserving fuel, soil organic matter and soil nitrogen.

For five years, Lindemann studied the conversion of farmland from a conventional till system to stubble and no-till systems at NMSU's Agricultural Science Center at Clovis. Under the different tillage systems, he considered the accumulation of organic nitrogen and organic carbon in soil planted in a sorghum-sorghum-fallow-wheat rotation. Lindemann's research results recently were published in Agronomy Journal.

In conventional tillage, farmers usually use moldboard plows or disks to plow under crop residues each season. Conservation tillage techniques leave at least 30 percent of the residue covering the soil surface after planting.

With stubble till, farmers use many of the same tillage tools as in conventional till, but they try to leave enough crop residue on the surface to reduce soil erosion. In no-till, the soil is left virtually undisturbed from harvest to planting. No-till requires more chemical inputs than stubble till for weed control.

"We've found that after five years, organic nitrogen, organic carbon and other soil factors have increased in the soil under stubble and no-till systems as compared to conventional systems," Lindemann said. "The stubble and no-till systems had very similar results, but the no-till conserved a little bit more organic nitrogen and organic carbon than did the stubble.

The differences were most notable during sorghum planting and growth, he added. Lindemann said these added nutrients mean the soil holds moisture better and resists erosion. More moisture in the soil is especially important to farmers in eastern New Mexico where lack of water can be the limiting factor for high yields.