Use of a Ryegrass Cover Crop to Remediate Excess Soil Nutrients In a Sorghum-Sudangrass Field.

Poultry litter can be used to fertilize sorghum-sudangrass pastures and hayfields.  If properly managed, litter can be returned to land; however, one concern regarding land application of poultry litter is soil nutrient accumulation.  Applying poultry litter to land at recommended crop N rates can lead to an accumulation of several nutrients in the soil.  One potential way to help remove excess nutrients is by incorporating a cover crop.  This study was conducted from 2005-2008 to observe changes in characteristic soil fertility properties after fertilization with poultry litter and/or inorganic fertilizers and with or without a ryegrass cover crop.  A completely randomized block design consisting of eight treatments was utilized: an inorganic N- P-K fertilizer without a cover crop (I-CC),  N- P-K fertilizer with a cover crop (I+CC),  poultry litter applied according to recommended P rate without a cover crop (PPL-CC), poultry litter applied according to recommended P rate with a cover crop (PPL+CC),  poultry litter applied according to recommended N rate without a cover crop (NPL-CC),   poultry litter applied according to recommended N rate with a cover crop (NPL+CC), poultry litter applied at recommended P rate with supplemental inorganic N fertilizer without a cover crop (NPPL-CC) and poultry litter applied at recommended P rate with supplemental inorganic N fertilizer with a cover crop (NPPL+CC).   Many of the nutrients (P, K, Ca, Mg, B, Cu, Zn, and Na) along with water pH, organic matter and CEC were significantly different by year, but very few by treatment (Ca, Mg, and CEC) (p<=0.05).  Indications are that use of a Ryegrass cover crop may not assist producers in lower soil nutrient accumulations, but will be useful as a second forage crop during the year.