Subsurface banding of poultry litter influence on runoff nutrient losses in a no-tillage maize cropping system

Abstract

Poultry litter (PL) is often used as an alternative nutrient source to inorganic fertilization for crop production in the southeastern US. Historically, PL has been broadcast applied on the soil surface, leaving the nutrients susceptible to runoff. Developments made in recent years allow for placing PL in narrow bands below the soil surface with minimal disturbance. This technological advancement could reduce the transport of P in surface water runoff from fields managed under conservation agricultural systems. Thus, a study was conducted to evaluate the influence of banding PL into a no-tillage corn (Zea Mays L.) field on P loss. Treatments consisted of surface banded PL, subsurface banded PL (3–5 cm below the surface), broadcasted PL, broadcasted commercial fertilizer (CF), and a nonfertilized control. The PL treatments were applied based on an N rate of 168 kg total N ha−1. For the CF, inorganic N was applied at a rate of 168 kg total N ha-1 and P at a rate of 45 kg P ha−1. Runoff events (40 min) were created using rainfall simulations (rainfall was applied at 89 mm hr−1). The greatest losses of dissolved reactive P and inorganic N occurred with the surface broadcast treatments. Subsurface band applying PL reduced P concentration losses and loading in surface water runoff to levels of the control. No differences were observed in runoff volume between treatments. Thus, total P losses mimic those observed for dissolved reactive P concentration in surface water runoff and loads. Approximately 60–80% of the total P concentration was dissolved reactive P regardless of application method. Subsurface band application reduced total P concentration by 95% when compared to surface broadcasted litter. These results show that subsurface band-applied PL can greatly reduce the impact of P loss to the environment when compared to conventional surface-applied PL and CF practices.