Crop and soil response to subsoil loosening, deep incorporation of phosphorus and potassium fertilizer and subsequent soil management on a range of soil types.: Part 1: Response of arable crops

Abstract

Abstract. Between 1978 and 1985 16 experiments tested crop response to subsoil loosening by either the Wye Double Digger or a winged subsoiler. Additionally, response to incorporation of 350 kg ha of P 2 O 5 and K 2 O into the subsoil was tested. Soil types were mainly well‐drained light‐and medium‐textured soils in arable rotations. Subsoil loosening increased the yield of spring‐sown crops on sandy soils in years of moderate to severe drought. Response was associated with deeper rooting and improved water extraction from the subsoil. No yield increases were recorded with autumn‐sown crops which were largely grown on the medium and heavy textured soils. There was a trend towards yield reductions on deep silty soils in wetter years. At one site only did the response to phosphorus and potassium fertilizer incorporated into the subsoil exceed that of fertilizer applied to the topsoil.