Understanding how management can prevent degradation of the structurally fragile soils of the Amazonian periphery

Jéssica de Freitas Nunes; Lorena Silva Campos; Alana das Chagas Ferreira Aguiar; Sacha Jon Mooney; Karina Andrade Pimentel; Emanoel Gomes de Moura

doi:10.1016/j.eja.2023.127037

Understanding how management can prevent degradation of the structurally fragile soils of the Amazonian periphery

Eur J Agron. 2024 Feb:153:None. doi: 10.1016/j.eja.2023.127037.

Authors

Jéssica de Freitas Nunes¹, Lorena Silva Campos¹, Alana das Chagas Ferreira Aguiar², Sacha Jon Mooney³, Karina Andrade Pimentel¹, Emanoel Gomes de Moura¹

Affiliations

¹ Postgraduate Program in Agroecology, Maranhão State University, São Luis, Maranhão 65000-000, Brazil.
² Department of Biology, Federal University of Maranhão, São Luís, Maranhão 65080- 805, Brazil.
³ School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE125RD, United Kingdom.

Abstract

The dynamics and responses to mulching management processes, which affect sustainability in tropical agroecosystems, remain poorly understood. Therefore, this study aims to evaluate and distinguish the short-and long-term effects of mulch of leguminous biomass on fertility of a tropical soil enriched with calcium. This experiment was conducted using the treatments: Long-term mulching (LTM) consisted of planting without mulch in 2019 in soil that had been mulched for six years previously, while short-term mulching (STM) consisted of planting without mulch for six years and with mulch only in 2019. LTM + STM consisted of planting in mulched soil for seven years (from 2013 to 2019), while LTM + synthetic nitrogen (LTM + sN) consisted of the LTM treatment with the addition of 150 kg N ha^-1. The remaining treatments were STM + sN; LTM + STM + sN; bare soil with sN, and bare soil without sN as control. In areas with LTM the interactions between products derived from biomass, sN, and Ca resulted in higher total SOC and BS, while STM maintained soil moisture, decreased penetration resistance, and enhanced N uptake providing biological nitrogen able to replace sN for maize nutrition. The positive effects of short- and long-term mulching were cumulative as they increased accumulated N by maize in 163%, and maize grain yield by 125% (4.77-10.78 Mg ha^-1) compared to cultivation with sN without mulch. Our results showed that interactions between continuos mulch of leguminous biomass, Ca and sN prevent degradation of agricultural land in Amazonian conditions. Therefore, this combination must be recommended to prevent Amazonian soil management, which in turn reduces the risk of new deforestation in Amazonian periphery.

Keywords: Base cations retention; Soil organic carbon stabilization; Sustainability; Tropical agrosystem.