Lettuce and Broccoli Response and Soil Properties Resulting from Tannery Waste Applications

Abstract

AbstractBroccoli (Brassica oleracea L. var. italica) and lettuce (Lactuca sativa L.) were grown on Willamette sil (Pachic Ultic Argixerolls) amended 1 and 2 yr earlier with chrome tannery wastes at rates up to 192 Mg ha−1 to determine nutrient and trace element availability. Soils were sampled at 0‐ to 15‐ and 15‐ to 30‐cm depths just before seeding the crops. Tannery waste increased soil pH, N, extractable Ca, B, and total Cr content and reduced soil extractable Mg and Fe content. Waste application had essentially no effect on soil K, P, S, Zn, Mn, Cu, Ni, Pb, Cd, and Mo content. The N concentration of lettuce grown on waste‐amended soil was higher than that of lettuce grown on untreated soils. Tannery waste did not consistently affect plant tissue concentrations of other nutrient or trace elements, including Cr. Yields of both crops increased when grown on tannery waste‐amended soil and were approximately equal to the yields obtained when commercial N fertilizer was applied at 112 kg N ha−1. This suggests that significant quantities of waste organic N were mineralized and made available. With proper safeguards, tannery waste may be an effective and safe crop fertilizer, and disposal on agricultural land may be an acceptable alternative to landfilling or trenching.