Soil Health Check-Up of Conservation Agriculture Farming Systems in Brazil

Jardel H. Passinato,Lúcio de P. Amaral,José A. A. Acosta,Telmo J. C. Amado,Amir Kassam

doi:10.3390/agronomy11122410

Jardel H. Passinato, Lúcio de P. Amaral + Show 3 more

Open Access

https://doi.org/10.3390/agronomy11122410

Copy DOI

Abstract

Conservation agriculture has been promoted as the main strategy to regenerate soil life but its effect on soil enzyme activity remains little documented. This study investigated the β-glucosidase and arylsulfatase enzymes as tools to evaluate soil health at the field level. Croplands in four main grain-producing states in Brazil were selected for this study. In each cropland, three environments (high yield (HYE), medium yield (MYE), and low yield (LYE)) were delineated for soil sampling to determine soil chemical attributes and enzyme activity. In one of these fields with a large temporal database, soil DNA characterization was also undertaken. The two soil enzymes investigated were affected by a range of soil attributes and the most important of these were identified. Around 40% of the data points sampled had low soil organic matter content; these were associated with low enzyme activity. Furthermore, in HYE there was more biodiversity and a higher presence of plant-growth promoters, while in LYE there were more plant pathogenic organisms.

Highlights

The projected global population growth over the coming decades will increase the demand for food, fibre, biofuel, energy, water, and other agricultural products
This study was carried out in seven grain production fields distributed in four states that have been continuously managed under Conservation agriculture (CA) over the past 10 to 20 years
These fields were selected because they offered crop yield records kept by the Aquarius Project team which were representative of farming systems currently adopted in their agro-ecoregion

Summary

Introduction

The projected global population growth over the coming decades will increase the demand for food, fibre, biofuel, energy, water, and other agricultural products. There will be growing pressure on natural ecosystems and agroecosystems, which are already facing sustainability challenges due to climate change and increasing soil degradation linked to loss of biodiversity, compromising a range of environmental services and crop productivity at different scales [1]. This scenario highlights the imperative need for the development of more sustainable agricultural systems. There is an urgent need for the redesign of agriculture production systems in order to decrease environmental, economic, and social costs associated with current intensive tillage-based production systems that create bare soils and entail high agrochemical applications [3,4,5]. The three interlinked principles that define CA are: (a) continuously minimizing or avoiding mechanical soil disturbance by tillage of all forms, including no inversion of soil layers, and reducing the rate of crop residue break down and avoiding mixing it into the soil, preventing short-term peaks of biological activity associated with flushes of carbon (C)

Objectives

Methods

Results