Agronomic efficiency of hidrolized cattle leather fertilizer as Nitrogen source and Chromium content in soil, water and plant

Abstract

The objective of this work was to evaluate the agronomic efficiency of a hidrolized leather fertilizer (HLF) as N source and environmental impact resulting from addition of chromium to soil using this fertilizer. The work was conducted in a greenhouse from Fepagro, Viamão, RS, Brazil, with growing of corn and radish in pots with three se- parate layers (0-20, 20-40 and 40-60 cm of depth) of two soils: Ultisol and Oxisol. Treatments were two doses of HLF, calculated based on its N content: necessary dose to supply N to corn or radish; half of previous doses, complemented with urea to equate the amount of N applied; and urea as standard N source. In plants were determined grain or bulb yield, shoot dry mass and N content in leaves, besides chromium content in shoot, grains and roots. After cultivation, percolated water through the soil and soil samples from the three layers were collected for chromium determination. Agronomic efficiency of HLF was similar to urea as N source to corn and radish in both soils, resulting in similar grain or bulb yield and N leaf content. Chromium contents in edible parts (grains and bulbs) of plants fertilized with HLF were not different to contents of plants fertilized with urea. Chromium, only in trivalent form, was retained in superficial layer (0-20 cm) of soils, where chromium content increased with HLF application, which resulted in no detection of chromium in percolated water through pots.