Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 22, 1998
Publication Date: N/A
Technical Abstract: Sustainable production has become a key issue in the management of cropping systems. This study examined changes in soil biochemical properties in the first 4 years after the initiation of no-till. The site was cropped to a corn-soybean rotation and both phases of the rotation were present at all times in the field. We collected soil cores to a depth of 15 cm in the fall of 1992-1995 after harvest. We quantified yearly changes in soil pH, total organic C (TOC), total N (TN), particulate organic matter C (POC) and N (PON), microbial biomass C (MBC), and potentially mineralizable N (PMN). TOC increased by 20% and POC increased by 50% between 1992 and 1993 as a result of cessation of tillage. Severe summer soil flooding decreased MBC by 50% between 1992 and 1993, but the effects of the flood were not apparent until 1994 for TOC, TN, POC, PON, and PMN. The most biologically active soil properties decreased by the greatest amount, which suggests these properties are more sensitive to ecosystem disturbance than TOC and TN. The effect of transition to no-till, although complicated by the flood effects, was most apparent in POC.