Poultry Litter Quantity Influences Collard Growth in Pots and Affects Cabbage Growth and Nutrient Uptake

Abstract

A greenhouse pot study was conducted with a Wynnville sandy loam surface soil to determine the influence of application rates of poultry litter (PL) on growth and nutrient uptake of collard ( Brassica oleracea, Acephata Group L., cv. Champion), and the residual effects of PL on growth and nutrient uptake of cabbage ( Brassica oleracea, Capitata Group L., cv. Rio Verde). PL at 0, 13, 26, 53, and 106 g·kg –1 was incorporated into limed (pH 6.5) and nonlimed (pH 5.2) soil. Collard plants were grown for 52 days. The residual effects of PL were evaluated by growing three successive crops of cabbage without further application of PL (total 218 days). Collard plants were severely damaged or killed within 7 days after transplanting when the application rate of PL exceeded 26 g·kg –1 soil. Maximum dry matter yield of cabbage shifted from 26 to 106 g PL/kg soil during three successive crops. After four successive growth periods, 6% to 37% of N, 3% to 62% of Ca, 20% to 120% of K, 5% to 60% of Mg, and 3% to 25% of P added through PL was removed by plants. The decrease in water-extractable K accounted for the decrease in the soil salinity. Our results suggest that application rates of PL ≥ 53 g·kg –1 soil can result in elevated levels of salts and NH 3 in soil, which can produce severe salt stress and seedling injury.