Sustainability of carrot-cowpea intercropping systems through optimization of green manuring and spatial arrangements

Josimar Nogueora Da Silva,Gardênia Silvana De Oliveira Rodrigues,Elizangela Cabral Dos Santos,Aridênia Peixoto Chaves,Jailma Suerda Silva De Lima,Jolinda Mércia De Sá,Francisco Bezerra Neto,Renato Leandro Costa Nunes,Vitor Abel Da Silva Lino

doi:10.1590/0103-8478cr20190838

Abstract

ABSTRACT: One of the biggest challenges in intercropping of two or more crops is to maintain their productivity as that of their sole counterparts. In order to obtain sustainable intercropping systems in a semi-arid environment, this study evaluated the agro-economic advantage and sustainability of intercropped systems of carrot and cowpea, optimizing the green manuring and spatial arrangements. Experiments were conducted in the period from July to October 2017 and 2018, using a randomized complete block design with the treatments arranged in a 4 x 3 factorial scheme, with four replications. Treatments included four amounts of M. aegyptia incorporated into the soil (20, 35, 50, and 65 t ha-1 on dry basis) with three spatial arrangements (2:2, 3:3, and 4:4) between the components cultures formed from cowpea rows alternated with carrot rows. The agro-economic advantage indices evaluated in the intercropping systems were: land equivalent ratio (LER), area-time equivalent ratio (ATER), score of the canonical variable (Z), actual yield loss (AYL), intercropping advantage (IA), gross income (GI), net income (NI), rate of return (RR), and profit margin (PM). The highest agro-economic advantages of the carrot and cowpea intercropping were obtained for LER, ATER, NI, and RR of 2.60, 4.16, US$ 8,720.99 ha-1, and US$ 2.21, respectively, for M. aegyptia biomass amounts of 46.42, 47.82, 32.60 and 31.51t ha-1 added to the soil. The 2: 2 spatial arrangement was the one with the best productive performance, with higher net income and rate of return in the intercropping of carrot-cowpea.

Highlights

IntroductionIntercropping has provided sustainable farming systems due to gains in crop productivity and a better use of the available environmental resources
Intercropping has provided sustainable farming systems due to gains in crop productivity and a better use of the available environmental resources.This is especially the case when the associated crops have some complementarity, which may be, more or less, depending on the management of the system
The agronomic advantage of the intercropped systems of carrot and cowpea as a function of green manuring and spatial arrangements was assessed through productivity and competition indices, while the economic advantage was estimated through economic indicators

Summary

Introduction

Intercropping has provided sustainable farming systems due to gains in crop productivity and a better use of the available environmental resources This is especially the case when the associated crops have some complementarity, which may be, more or less, depending on the management of the system. Green fertilization promoted several benefits to the soil, mainly because it provides a greater coverage, preservation, restoration, and increase in soil organic matter contents, with a higher biomass production potential and nutrient absorption and accumulation capacity. These factors are of great importance to the soil-plant system because they are related to nutrient cycling, increasing nutrient availability to cultivated plants (ALBUQUERQUE et al, 2013). Green fertilization in crop systems with food crops and vegetables with spontaneous species of the Caatinga biome is an excellent strategy to increase the amount of nutrients in the soil (BEZERRA NETO et al, 2014), because these species present the same benefits as the species introduced in relation to biomass production and nutrient cycling, favoring the soil biota and positively contributing to successive agricultural crops (FAVERO et al, 2000)

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