Influence of the application of biosolids on the content of humic and fulvic acids in soil cultivated with sugar cane

Abstract

This study evaluated the effect of the application of biosolids from a municipal wastewater treatment plant on the content of humic and fulvic acids in vertic Endoaquept soil cultivated with sugar cane. Eight treatments with a randomized block spatial distribution are evaluated using experimental units of 6 m wide x 20 m long: i) control; ii) mineral fertilizer; iii) dehydrated biosolid 1N and 2N; iv) thermally dried biosolid 1N and 2N; and v) alkalized biosolid 1N and 2N (1N and 2N correspond to doses equivalent to one and two times the nitrogen requirement for sugar cane). The results show that while values of humic and fulvic acids showed no significant differences between the control, mineral fertilizer and alkalized biosolid treatments, the application of dehydrated and thermally dried biosolid treatments increased humic acid and fulvic acid content in the soil. This finding demonstrates the benefits of applying such biosolids.