Nutrient additions for composting of tree prunings in semi-arid northeastern Brazil

Abstract

A major problem in the recycling of organic wastes in semiarid region is the low concentration of nutrients in the biomass available. The aim of this study was to evaluate the effects of additions of gliricídia biomass as a source of N, and rock powder MB-4 as source of Ca and Mg on the quality and potential nutrient supply of organic compost produced from pruning mango and cattle manure in the semiarid region of NE Brazil. The study was conducted in two stages. First, was at the field of composting in the Fazenda Tamanduá, located in Santa Terezinha – PB, where heaps were constructed of 100 kg in a randomized design with four treatments and four replications. Second, the organic compounds were tested in an assay using a randomized design in a greenhouse using maize plant as an indicator of nutrient available. The addition of gliricidia biomass resulted in organic compost with the highest concentration of N (12.1 g.kg-1) and the low C/N ratio (13.9). However, the addition of MB-4 did not lead to higher concentration of Ca and Mg compost. The analyses of variance for the accumulation of nutrients in maize plants showed no significant between the organic composts, but with significant differences compared to control treatment. The addition of gliricidia biomass in the composting the pruning wastes and cattle manure leads to the production of organic compost the best quality.