Determination of BR 1 peanut cultivation coefficient for Agreste Alagoano

Abstract

Agreste Alagoano has high representativeness in peanut production in the State of Alagoas. One of the frequent practices for efficient irrigation management in different crops is the determination of the crop coefficient (Kc). Therefore, the objective was to determine the Kc of the peanut crop in the Agreste Alagoano by the methods of Penman-Monteith (FAO standard) and Hargreaves-Samani. The research was carried out in the experimental unit of the Irriga Group of the Arapiraca Campus, Federal University of Alagoas (UFAL), from December 13, 2019 to March 11, 2020. Five drainage lysimeters with a diameter of 0.30 m were installed, corresponding to a soil surface of 0.0707 m2, to obtain the Culture Evapotranspiration (ETc) determined via slimcap system, while reference evapotranspiration (ETo) was determined by the standard methods FAO Penman-Monteith and Hargreaves-Samani. The Kc was obtained from the ratio between ETc by ETo. Kc values were found by the Penman-Monteirh method for peanut cultivation of 0.64; 0.64~0.89; 1.29 and 1.29~1.18 for phases I (1-30 DAS), II (31-50 DAS), III (51-80 DAS) and IV (81-89 DAS), respectively, while for the Hargreaves-Samani method values of 0.72 were found; 0.72~0.99; 1.40 and 1.40~1.25 for phases I (1-30 DAS), II (31-50 DAS), III (51-80 DAS) and IV (81-89 DAS), respectively.