Impact of Strip-Tillage on Soil Properties Compared to No-till in Corn Production Systems.

In a previously related study corn (Zea mays L.) grain yield averaged over six growing seasons increased 8% with strip-till (ST) over no-till (NT). The crop in ST consistently had greater nutrient uptake efficiency per unit of root surface area relative to NT. Our objective was to determine the effect of ST on soil properties that may help elucidate the differences in crop performance. Corn was planted in 2012 and 2013 in an ongoing study started in 2007 near Urbana, IL where soil organic matter, penetration resistance, infiltration rate, water aggregate stability, and bulk density were measured during the corn phase of a corn-soybean rotation. Penetration resistance was measured at 0, 12, 24, and 36 cm from the crop-row to a depth of 30 cm in 2.5 cm increments and averaged over the 0-5, 5-10, and 10-30 cm depths. All other soil properties were measured at 0 and 36 cm from the crop-row. Bulk density was determined for the 0-5, 5-10, 10-30, and 30-50 cm increments. Soil organic matter was greater in ST (3.8%) compared to NT (3.5%) and across tillage systems was reduced in the crop-row compared to 36 cm from the crop-row by 5.4%. Relative to NT bulk density in ST was reduced by 3.4% and penetration resistance was reduced by 45% and by 27% in the 0-5 and 5-10 cm depths respectively. Within the 36 cm position water aggregate stability increased in NT (88.4%) compared to ST (83.6%), and increased within NT from the 0 to the 36 cm crop-row position by 6.6%.  Infiltration rate was not influenced by tillage or crop-row position. Increased SOM, and reduced PR and BD in ST are likely responsible for the greater yield and nutrient uptake efficiency previously measured in ST compared to NT.