Effects of Pasture Renovation On Hydrology, Nutrient Runoff, and Forage Yield.

Pasture renovation is a management technique that can be used to increase forage yield and reduce nutrient runoff.  Two plot studies and one watershed study were performed to assess the benefits of pasture renovation on both of these factors.  Small plots were renovated prior to manure application (poultry litter or swine slurry) on different pasture soils followed by a series of rainfall simulations.  Renovation was also performed prior to manure application (poultry litter) on a 0.23 ha watershed with natural runoff collected following storm events.  Renovated small plots fertilized with poultry litter led to reductions in dissolved reactive P (DRP) (74 to 88%), total P (TP) (76 to 84%), and total nitrogen (TN) (72 to 78%) loads in two of the three soils studied following initial rainfall simulation events.  Forage yields remained relatively unchanged by renovation.  The renovated watershed had reduced P loads in the initial 3 months of the first study year but greater annual runoff volumes and P loads than the non-renovated watershed.  Forage yields were 30% greater on the renovated watershed.  Results of the watershed study, however, were inconclusive due to high variability and low replication.  Overall results of all studies identified beneficial impacts of renovation for the first three months following renovation/fertilization, the most important period for nutrient loss to occur.  Therefore, renovation could be used as a best management practice in these areas.