MINERALIZATION OF NITROGEN AND CARBON FROM ORGANIC COMPOST FROM ANIMAL PRODUCTION WASTE

Maria Diana Melo Araújo,Carlos Alberto Kenji Taniguchi,Marina Monteiro Feitosa,Henrique Antunes De Souza,Anaclaudia Alves Primo

doi:10.1590/1983-21252020v33n204rc

Abstract

ABSTRACT Elucidating the mineralization of organic composts makes it possible to understand the release of nutrients to plants. The objective of this study was to evaluate the mineralization of nitrogen (N) and carbon (C) from organic compost from residues of the production and slaughter of small ruminants, applied on a Neossolo Flúvico (Fluvents). The compost consists of remains of grass (forage), manure and slaughter residues such as blood, viscera and the carcass of goats and sheep. Under laboratory conditions, two experiments were conducted in a completely randomized design, considering the doses of organic compost at the following levels: zero; 3.75, 7.5, 15 and 30 Mg ha-1. For the N and C mineralization tests, 11 and 32 collection times (sampling periods) were evaluated, respectively. Inorganic N content (ammonium and nitrate) was measured in the N mineralization test, and CO2-C concentration was quantified in the C mineralization test. The largest increments between the applied doses of organic compost from residues of the production and slaughter of small ruminants were 70% and 69% for potentially mineralizable N and C, with amounts of 7.5 and 30 Mg ha-1 at doses of 3.75 and 7.5 Mg ha-1, respectively. Organic C and N from residues of the production and slaughter of small ruminants are rapidly mineralized in the soil (up to 45 days) due to their low C/N ratio.

Highlights

The Brazilian Northeast region has the largest national herd of goats and sheep, approximately 7.7 and 9.0 million heads, respectively, and most of them belong to family farmers (MAGALHÃES et al, 2018)
In order to better verify the behavior of ammonium and nitrate concentrations along the incubation, it was opted to present the data of the control and of the highest and lowest doses of the organic compost
In a study on N mineralization in poultry litter applied in Cambissolo Húmico (Inceptisol), the nitrate content increased simultaneously with the reduction in ammonium contents due to the oxidation of ammoniacal N by nitrifying bacteria (ROGERI et al, 2015); according to the authors, the variation of ammonium and nitrate contents was characterized by a sigmoid curve, ascending for nitrate and descending for ammonium

Summary

Introduction

The Brazilian Northeast region has the largest national herd of goats and sheep, approximately 7.7 and 9.0 million heads, respectively, and most of them belong to family farmers (MAGALHÃES et al, 2018). Through the composting process, this byproduct of the goat and sheep production activity can be reintroduced into the production systems, avoiding possible environmental problems, recycling nutrients and enabling its use as organic fertilizer (SOUZA et al, 2019). The semiarid region has low use of inputs, especially because of its low natural precipitation and dry spells, which lead to soil degradation, mainly due to the decrease in fertility (MENEZES et al, 2012). The use of organic materials is extremely important, especially in low-tech systems (MENEZES et al, 2012; SOUZA et al, 2014a)

Objectives

Methods

Results

Conclusion