Abstract

Poultry manure provides a rich organic nutrient source to fertilize crops and help neutralize soil acidity. However, the usual practice of broadcasting litter on the surface of pastures and other no-till systems can degrade water quality by allowing nutrients to be transported from fields in surface runoff, while much of the ammonium-N volatilizes and escapes into the atmosphere. In a previous study, we used a subsurface banding technique to move litter from the soil surface into the root zone with minimal disturbance of the grass, thatch, and soil structure; and found that nutrient losses decreased substantially. Because subsurface banding increased retention of nutrients and water in the soil, we conducted follow-up research to compare crop yield and quality from this litter application method to those from the conventional surface broadcasting method. The objectives were to determine effects of subsurface application on perennial forage yield, quality, and temporal yield distribution during the growing season. Field plots were located on silt loam soil (8-10% slopes) with well-established bermudagrass (Cynodon dactylon L. Pers.). Poultry litter was applied (6.7 Mg ha^-1, dry weight) by one of two methods: surface broadcast manually or subsurface banded using a tractor-drawn prototype implement. Each treatment was replicated three times. There were also three control plots that received no litter. Results showed that subsurface application generally increased forage quality and yield, especially in the latter part of the growing season when forage production from surface-applied litter began to decline. Under the growing conditions in this study, subsurface application increased mean forage yield by as much as 40%.

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