Greater water availability increases the water use efficiency and productivity of corn and bean species grown in secondary crop systems

Abstract

Secondary crop cultivation is very important for producers of corn and beans crops worldwide, and can reach high levels of productivity. The study aimed to evaluate water use efficiency and grain yield response of corn and bean species cultivated in a secondary crop system, when subjected to different water levels. Two experiments were carried out, one for the corn cultivar DKB 240 and another for the bean cultivar IPR Gralha; the study was developed in an experimental area classified as Oxisol typical, both experimental designs consisted of a randomized single factor block design with five water levels (0, 50, 75, 100 and 125% of reference evapotranspiration; Eto) with three replications. The following variables were analyzed: number of rows per ear, number of grain per row, thousand grain mass and grain yield for corn; number of pods per plant, number of seeds per pod, thousand grains mass and grain yield for beans. Water use efficiency was calculated as the relationship between grain yield and the applied water level. The corn and bean crops had the highest water use efficiency in the levels of 100% and 125% of reference evapotranspiration, respectively. These levels showed the highest yield of crops. Both corn and beans can be recommended for planting in the second crop system as they present a high yield potential under favorable water conditions; in order to meet water demands, they require a total of 413.53 mm for corn and 447.12 mm for the bean cultivar distributed throughout the crop cycle.

Water deficit tolerance of bean cultivars

“…When likening these values to those found for other crops mentioned above, it appears that these values are even lower than those verified in a situation of low atmospheric demand. These results distress production in the future scenario, showing the need for additional research to assess the largest possible number of cultivars in search of those that are the most water efficient (Schwerz et al, 2017). One of the practical tools for assessing the water status in crops is the measurement of the canopy temperature.…”

“…Despite socioeconomic importance, there is a fluctuation in grain supply related mainly to water deficit, which is one of the main yield limitations (Devi et al, 2013;Zadraznik et al, 2013;Schwerz et al, 2017). The average yield of the bean crop in Brazil is 66.2% lower than its potential, with an average of 1,014.6 kg ha -1 in 2015/2016 to 2019/2020 crops (Conab, 2021).…”

“…One of the main mitigation and adaptation strategies to current and future food production scenarios is the choice of cultivars that most resourcefully use the available soil water (tolerant to water deficit), and are adapted to production in regions with edaphoclimatic conditions (Peter et al, 2020), as water deficit will become more and more recurrent in subtropical regions due to scarcer rainfall and greater evaporative air demand (Vicente-Serrano et al, 2020;Schwerz et al, 2017). In Latin America, the water deficit is one of the key limiting factors for bean production (Rosales et al, 2012).…”

“…In the state of Rio Grande do Sul (RS), Brazil, beans that are planted in the main season, whose sowing occurs from August, are exposed to more favorable development conditions. The intensified cultivation of the off-season, whose sowing occurs in January and February, may affect the offer of markets due to low production, as it is susceptible to drought periods, due to irregular rains and available solar radiation (Schwerz et al, 2017). The authors perceived that the water deficit in the off-season in municipality of Frederico Westphalen, RS occurred in the flowering, filling, and maturation stages of the pods, and negatively impacted yield, as it needs the use of irrigation.…”

Estimation of common bean (Phaseolus vulgaris) leaf area by a non-destructive method

“…Phaseolus vulgaris. yields in common bean (Schwerz et al, 2017). Water deficiency lowers cell turgor, which, in turn, reduces leaf expansion, induces stomatal closure and reduces plant physiological processes, ultimately compromising grain production (Taiz, Zeiger, Moller, & Murphy, 2017).…”