Water use of cowpea under deficit irrigation and cultivation systems in semi-arid region

Tiago S Leite,Jeferson L D Dombroski,Narjara W Nogueira,Rômulo M O De Freitas,Francisco C L De Freitas,Sidney C Praxedes

doi:10.1590/1807-1929/agriambi.v23n4p271-276

Abstract

ABSTRACT The resilience of crops to drought depends heavily on the cultural practices adopted, which can have a direct effect on water use efficiency. The aim of this study was to assess the influence of irrigation intervals on the growth, water consumption and water use efficiency of cowpea crops (cv. BRS Guariba) under conventional and no-tillage systems. The experiment was carried out in the semi-arid region of Rio Grande do Norte, Brazil, using a split-plot in a randomised complete block design, with four replications. Treatments consisted of two cultivation systems in the whole plots (conventional and no-tillage) and six irrigation intervals in the subplots (2, 6, 10, 14, 18 and 22 days) which were applied at full bloom. The biomass of the different parts of the plant, leaf area and leaf area index were assessed at 64 days after sowing (DAS) and grain yield, water consumption and water use efficiency at 70 DAS. No-tillage is a promising cultivation technique for cowpea crops, promoting higher grain yield and water use efficiency under semi-arid conditions. This system allows cowpea cultivation with irrigation intervals of 10 or 14 days, with no or small reduction in yield, respectively.

Highlights

Cowpea [Vigna unguiculata (L.) Walp.] has good capacity to withstand drought, by restraining its own growth, especially in the vegetative stage, and resuming it with the return of rainfall, allowing recovery of plant mass in a very effective way (Hall, 2012).Grain yield of cowpea in the northeast region of Brazil is relatively low due to the low-cost technologies applied, with values ranging from 300 to 400 kg ha−1 (Soares et al, 2006; Freire Filho et al, 2011)
Significant differences were observed for all variables assessed, both in cultivation systems and irrigation intervals
Under no-tillage, these variables showed a sigmoidal pattern, with little decrease up to 10 days without irrigation and falling rather abruptly after this. These results indicate that no-tillage attenuates the effect of water deficit on plants, as reported for common bean by Pavani et al (2008)

Summary

Introduction

Cowpea [Vigna unguiculata (L.) Walp.] has good capacity to withstand drought, by restraining its own growth, especially in the vegetative stage, and resuming it with the return of rainfall, allowing recovery of plant mass in a very effective way (Hall, 2012).Grain yield of cowpea in the northeast region of Brazil is relatively low due to the low-cost technologies applied, with values ranging from 300 to 400 kg ha−1 (Soares et al, 2006; Freire Filho et al, 2011). Soil management practices have a direct influence on crop yield and are determinants of economically viable production (Souza et al, 2014). Among these practices, there are the conventional and no-tillage systems. The surface organic matter in no-tillage systems helps to prevent extreme temperature fluctuations in the soil, acting as insulation (Bizari et al, 2009; Coelho et al, 2013a) In view of these characteristics, when compared to the conventional system, no-tillage can promote higher yield under deficit irrigation (Souza et al, 2016)

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Methods

Conclusion