soybean no till

Many questions have surfaced regarding short-and long-term impacts of corn (Zea mays L.) residue removal for use in the biofuels industry. To address these concerns, a field study was established in eastern South Dakota in 2000 using no-till soil management within a 2-yr corn/soybean [Glycine max (L.) Merr.] rotation. The objective of this study was to examine the effects of three residue removal treatments of low (corn harvested for grain; all residues remain on soil surface), medium (corn harvested for grain; residue raked, baled, and removed), and high (aboveground corn biomass and grain removed) on soil quality, measured through particulate organic matter (POM), soil organic matter (SOM), wet aggregate stability (WAS), and dry aggregate size distribution (DASD). Following four complete rotational cycles, when residue was removed from the soil surface there was a consistent decrease in the amount of SOM and all fractions of POM regardless of aggregate size class, indicating a possible decrease in soil quality. This was further indicated by the near doubling of the erodible fraction in the high removal treatment compared to the low removal treatment. Potential further degradation of the soil structure is indicated by a shift in DASD among the residue removal treatments. Within this study, removal of corn residue had a negative impact on the soil physical and chemical properties measured, potentially illustrating the importance of crop residue to maintain our soil resource. Additional research is needed to incorporate other soil chemical and biological indicators before recommendations can be made.