Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2006
Publication Date: 5/30/2007
Citation: Grigera, M.S., Drijber, R., Wienhold, B.J. 2007. Redistribution of crop residues during row cultivation creates a biologically enhanced environment for soil microorganisms. Soil & Tillage Research. 94:550-554. Interpretive Summary: In row cultivation is a common management practice in corn production systems. We measured the effect this practice has on the distribution of soil C and microorganisms. In row cultivation redistributes soil C from the furrow to the row. Soil microorganisms respond to this redistribution by increasing biomass in the row compared to the furrow. We speculate that this redistribution of soil C creates an enhanced zone of biological activity in the row that may improve early season corn growth through increased nutrient availability.
Technical Abstract: Formation of ridges during row cultivation creates microsites that could enhance spatial heterogeneity of soil properties, such as organic C, and thereby influence soil microbial communities. A study was conducted during 2003 near Shelton, NE, on a corn (Zea mays L.) field mapped using apparent electrical conductivity (ECa). New ridges were built each year with a row cultivator when corn reached the V3-V4 growth stage. Cultivation increased labile C fractions and soil microbial biomass in the row position for all ECa classes. Canonical discrimination analysis showed no clear differences in relative abundance of specific microbial groups among ECa classes or between row and furrow position, except for enhanced mycorrhizal biomass in the row. Microbial biomass responded strongly to changes in C redistribution, but was not accompanied by a significant change in the abundance of specific microbial groups. Labile C fractions (coarse and fine particulate organic matter) and crop residues in diverse stages of decomposition are associated with diverse microbial groups. Thus, row cultivation for weed control creates a biologically enhanced root zone that may improve early season performance of corn.