Assessing the Macro- and Micro-Pore Distribution and Effect On Permeability and Infiltration of a Forage Grass On Coastal Plains Soils.

Implementing forage grass into a traditional peanut-cotton rotation is a fairly new concept.  It has been shown to improve crop quality and sustainability, but the cause is not well understood.  Some of the benefits of the sod-based rotation can be seen through an increase in organic matter in the soil, less damage to the crop due to weeds, disease, and pests, and greater nutrient cycling.  The objective of this study was to determine whether the addition of forage grasses to the peanut-cotton rotation affects bulk density, permeability and infiltration, and total soil organic carbon.   Sites in Headland, AL, and Quincy, FL, were established 8-10 years ago with all combinations of sod-based (bahia-bahia-peanut-cotton) and traditional peanut-cotton (Headland site) or peanut-cotton-cotton (Quincy site) rotation replicated three times.  Permeability, at approximately 15 cm soil depth, and infiltration were determined using in-situ field techniques. There were no differences in permeability due to management system; however, permeability did differ by cropping sequence.  No difference was seen in the infiltration rates at field saturation for either management system, but there a difference was seen in infiltration rates between the various cropping sequences.  There were no differences between cropping sequence or management system for carbon, but there was a greater amount in the top 5 cm of the soil than the rest of the profile.  It was noticed that at the Quincy location there was more carbon in the top 5 cm than at the Headland location.