Characteristics Physico-Chemical and Carbon Balance in Fluvic Entisol after Six Years Fertilization with Manure and Gliricidia

Abstract

Soils in the semi-arid region of northeastern Brazil have low natural fertility and therefore, plant growth and productivity can be adversely affected. The application of mineral fertilizers is economically unfeasible by farmers in this region. The use of organic inputs found in farms, such as animal manure and the biomass of gliricidia leaves and branches (Gliricidia sepium Jacq. Walp), is a viable and low-cost option. Thus, the objective of this study was to evaluate influence of organic fertilizations over six years on the physical and chemical characteristics of a Fluvic Entisol cultivated with beans, cotton, corn and sunflower was evaluated. Fertilizations, of 20 Mg ha -1 year -1, were: GIsoil-incorporated gliricidia; GS -surface gliricidia; EI + GI -manure and incorporated gliricidia; EI + GS -soil -incorporated manure and surface gliricidia, EI -soil -incorporated manure; and controlwithout addition of organic fertilizer. In the combined applications, half the fertilizer came from each source. All fertilization systems decreased bulk density, compared to the control treatment, and in the EI + GS system, there was an increase in total soil porosity. The GS system resulted in the largest SOM stocks and C / N ratio. The EI + GI system increased the total phosphorus stock. The use and application of gliricidia biomass as a green fertilizer over time improves the soil physical and chemical conditions, promotes good agricultural productivity without the need of mineral fertilizers, being an alternative of high relevance in the reduction of costs in agricultural practices.

Technical viability of improving soil chemical characteristics by using biofertilizers

“…The agronomic efficacy of using Gliricidia sepium to formulate biofertilizers was reported by Alakhyar et al (2019), since these formulations are able to supply the needs of different crops and maintain the soil fertility, especially when associated with cattle manure (Garrido et al, 2017). Since this species is a leguminous plant able to fix atmospheric nitrogen in symbiosis with rhizobia, besides being tolerant to water stress and easy to propagate, it is considered an important alternative to provide greater autonomy to and reduce the costs of family farmers (Primo et al, 2018).…”

Leguminous Alley Cropping Improves the Production, Nutrition, and Yield of Forage Sorghum

“…When studying Gliricidia and Leucaena alleys as a way to improve soil properties, Fernandes et al [27] found that the residues incorporated 160 and 130 kg ha −1 year −1 of N, respectively (when only considering N). The leguminous alleys recovered about 20% of N directly from the residues deposited in the soil [11][12][13][14][15][16]. BNF can also represent N inputs relevant to the soil/plant system and reduce the need for N fertilizer application, which is often expensive and most susceptible to losses [8].…”