Poultry Litter Band Placement in No‐Till Cotton Affects Soil Nutrient Accumulation and Conservation

Abstract

Core Ideas Applying poultry litter in bands below the soil surface leads to greater conservation of most litter‐derived nutrients. Fertilizing cotton with poultry litter, despite supplying additional Mn, leads to reduced extractable soil Mn and tissue Mn levels. A yearly application of 6.1 Mg ha‐1 poultry litter for three consecutive years failed to increase soil total C and N. The effect of subsurface poultry litter band placement relative to the plant row on long‐term nutrient conservation has not been fully investigated. The objective of this study was to determine whether poultry litter band placement affects the accumulation and conservation of selected soil nutrients in a no‐till cotton (Gossypium hirsutum L.) cropping system. The treatments consisted of an average of 6.1 Mg ha‐1 litter applied in 1.02‐m‐spaced subsurface bands (wide, SSw), 0.30‐m‐spaced subsurface bands (narrow, SSn), or 0.30‐m‐spaced surface bands (narrow, SFn); an unfertilized control (UTC); and a soil test‐based synthetic fertilizer treatment (Std). The results showed, relative to the Std, poultry litter, regardless of the placement, resulted in accumulation of extractable soil P, K, Mg, and Zn but not total C or N. A key finding in this study is that litter, despite supplying a 3‐yr total of 10.2 kg ha‐1 Mn, reduced extractable soil Mn by an average of 20% and cotton tissue Mn by as much as 40% relative to the Std treatment. The accumulation of extractable soil P and K and to some extent Mg and Zn was greater when litter was applied by subsurface rather than surface banding. The difference between the SSw and SSn treatments in extractable nutrient conservation was not consistent. Overall, this study showed applying poultry litter in subsurface bands rather than surface bands leads to greater conservation of nutrients. Regardless of the band placement, poultry litter reduced tissue and extractable soil Mn which may be beneficial to cotton production in soils with marginally low pH.