Soybean Yields as Influenced by Peanut Hull Applications1

Abstract

AbstractPeanut (Arachis hypogea L.) hulls are a waste product that have potential for increasing crop yields when recycled to agricultural land as a source of nutrients and as a mulching material. This study was conducted to determine if peanut hulls could be applied at disposal rates and simultaneously increase soybean [Glycine max (L.) Merr.] yields as a result of increased nutrients and moisture in the rooting zone of soils that are acid and have a high exchangeable A1 content that restricts the soil volume available for root proliferation. Peanut hulls were applied to a Tatum (Typic Hapludults, clayey, mixed, thermic) silt loam soil at rates of 0, 21, 42, and 84 × 103 kg/ha on unfertilized plots and plots that received 49 kg P and 93 kg K/ha. In 1977, a year of moisture stress, peanut hulls increased the yield of seed by 500 kg/ha and forage by 1,560 kg/ha as a result of increased plant available moisture in the fertilized plots. Moisture in the 15 to 30 cm zone averaged 0.33 mm/cm greater in the peanut hull plots. On the unfertilized plots bean yields increased at a linear rate with each 1,000 kg/ha of hulls producing 21 kg/ha of seeds. This response resulted from an increase in both available P and moisture. In 1978, a year of more optimum moisture conditions, hull application did not increase yields in the fertilized plots. Yields in the unfertilized plots could be described by a second order polynomial and approximately 50 × 103 kg/ha of hulls were required to equal yields produced with fertilizer application. Hulls significantly increased the P concentration in the tissue for both the unfertilized and fertilized plots. The P concentration increased by 0.01% for each 5,000 kg/ha of hulls applied for both the unfertilized and fertilized plots. Application of peanut hulls to soils that restrict root proliferation can supply the nutrients needed for soybean production and create more favorable soil moisture conditions.