Integrated systems improve the sustainability of soybean cultivation in the tropical region

Abstract

Inter-cropping between annual crops with tropical forages through integration crop-livestock systems (ICL) is considered a sustainable option to increase crop diversity and soybean productivity. In this study, we evaluated (1) the biomass production, desiccation efficiency, nutrient accumulation, and biomass decomposition of soil crop residues produced by Panicum maximum plants intercropped with maize in two different sowing methods during the second harvest and (2) investigated how soil crop residues impact the productivity of soybean. The experiment was conducted in a complete block design with three replicates. We compared conventional soybean cultivation with soybean cultivated over soil crop residues produced by a previous integration between maize and two Panicum maximum cultivars: Tamani and Zuri guinea grass, within and between rows of maize plants. Our results showed that Tamani guinea grass showed the highest desiccation efficiency. Zuri and Tamani guinea grass cultivated within and between maize plants resulted in higher biomass production and nutrient cycling potential, resulting in an increase of 28.4% in soybean productivity, compared to soybean grown without soil crop residues. We concluded that ICL system is an efficient method to increase the sustainability of soybean cultivation.

Crop-Livestock Integration Improves Physical Soil, Agronomic and Environmental Aspects in Soybean Cultivation

“…So far, it is undeniable that this intensification of land use, provided by the adoption of crop-livestock integration after the summer crop (the first crop of the agricultural calendar) is sustainable because it is technically feasible and economically resilient because it diversifies production [4,6,39]; socially fair, by keeping human resources in the field, given the optimization and rational use of labor [40]; and environmentally correct [8], by: (i) promoting the sequestration of atmospheric carbon [26], (ii) biologically decompressing the soil, contributing to erosion control and restoring the hydrological cycle [16,21,22], (iii) suppressing diseases and weeds, reducing the use and selection of herbicide-resistant plants [41] and (iv) cycling nutrients, reducing the demand for synthetic fertilizers [23,28]. For these reasons, CLI has recently been used by the Brazilian government to define public policies on agricultural credit, deforestation control and greenhouse gas mitigation.…”

“…According to Dias et al [23] the biomass mulch half-life is considered to indicate the durability of the biomass on the soil surface. When adopting integrated systems, it is necessary to choose cover plants that achieve high residue production and keep the soil covered for a longer period, especially in regions such as the Brazilian Cerrado where the decomposition of plant biomass is accelerated by soil and climate conditions [4,23,28].…”

“…In recent decades, Brazil has been a world leader, especially in agribusiness [1,2], due to technological innovations, the efficient use of inputs and large-scale cultivation resulting from agricultural mechanization. It is a country that has the necessary resources to increase food production and contribute to the world's food supply [3,4]. The use of this technology has made it possible to expand the frontier to previously marginalized regions, especially the Cerrado region, which has contributed greatly to increasing the country's grain, livestock and agro-energy production [5,6].…”

“…For this reason, the recovery of the soil's physical quality is of agricultural and environmental importance, especially in tropical regions, such as the Latossolos in Cerrrado [in the Brazilian Soil Classification System-Santos et al [19]; Oxisols in the USA Keys of Soil Taxonomy-Soil Survey Staff (2014); and Ferralsols in the World Reference Base for Soil Resources-IUSS Working Group WRB (2015)], in soils that are highly susceptible to compaction [13]. However, due to the high demand for investments in the mechanical decompaction process, alternative techniques have been sought to amortize operating costs and ensure agronomic sustainability [4,20].…”

“…As a result, there is an increase in water infiltration in the soil and subsequent availability for crops, as well as a reduction in surface runoff, which prevents the erosion and pollution of water sources [25,26], contributing to the maintenance of environmental services. An increase in agricultural productivity has also been reported with a reduction in the use of inputs, providing an agronomically efficient and environmentally friendly production system [4,27,28].…”