Evapotranspiration and crop coefficients in two irrigated wheat cultivars

Tonny J A Da Silva,William Fenner,Edna M Bonfim-Silva,Thiago F Duarte,Thiago H F M Castañon,Jefferson V José

doi:10.1590/1807-1929/agriambi.v24n4p252-257

Abstract

ABSTRACT In the state of Mato Grosso, Brazil, wheat is an alternative to the current production system, mainly in irrigated crops, with new cultivars improved for this environment and system. The objective was to determine the evapotranspiration of the irrigated wheat crop and the dual coefficients of cultivars for the Brazilian Midwest. The experiment was conducted in the field using 12 weighing lysimeters and mini-lysimeters, filled by soil monoliths. The wheat cultivars BRS-254 and BRS-394 were used in the first and second years, respectively. Reference evapotranspiration was obtained by the Penman-Monteith equation and crop evapotranspiration by the mass difference in the lysimeters. Basal crop coefficient and soil water evaporation coefficient were determined according to the crop development stages in both years of cultivation. The mean ETc and ETo values were 3.87, 3.49 mm d-1 and 4.10 and 3.23 mm d-1, respectively, in the first and second cultivation cycles, with higher values of ETc recorded in the reproductive stages of the crop, flowering and grain filling. The basal crop coefficients and soil water evaporation coefficients estimated by weighing lysimeters composed of soil monoliths are: Kcb - 0.42, 0.78, 0.94, 0.74 and 0.47 and Ke - 0.72, 0.52, 0.39, 0.58 and 0.13 for the cultivar BRS-254, and Kcb - 0.28, 0.27, 0.65, 0.98 and 0.66 and Ke - 1.04, 0.96, 0.65, 0.34 and 0.51 for the cultivar BRS-394, at the stages of emergence, tillering, flowering, maturation and harvest, respectively.

Highlights

Wheat (Triticum aestivum) is one of the main cereals used for human consumption
In the state of Mato Grosso, Brazil, wheat is an alternative to the current production system, mainly in irrigated crops, with new cultivars improved for this environment and system
The basal crop coefficients and soil water evaporation coefficients estimated by weighing lysimeters composed of soil monoliths are: Kcb - 0.42, 0.78, 0.94, 0.74 and 0.47 and Ke - 0.72, 0.52, 0.39, 0.58 and 0.13 for the cultivar BRS-254, and Kcb - 0.28, 0.27, 0.65, 0.98 and 0.66 and Ke - 1.04, 0.96, 0.65, 0.34 and 0.51 for the cultivar BRS-394, at the stages of emergence, tillering, flowering, maturation and harvest, respectively

Summary

Introduction

In Brazil, the best wheat yields are being obtained in the Midwest region (Borém & Scheeren, 2015) in irrigated cultivation systems, with flour quality higher than that obtained in the southern region of the country, with predominance of rainfed cultivation, evidencing the potential of central Brazil for self-sustainability in flour production, since the country has a production deficit of about 7 million tons per year (USDA, 2018) In this context, the state of Mato Grosso, Brazil, has the potential for the production of quality wheat (Guerra et al, 2003). As the water demand of crops is site-dependent, it is essential to study the evapotranspiration of wheat crop in the state, supporting new studies and being a source of information for government policies and decision making by professionals in the area and rural producers regarding the irrigation management of the crop (Paredes et al, 2014)

Objectives

Methods

Results