Efeito de diferentes níveis de déficit hídrico sobre o rendimento das culturas de Amendoim, Feijão-nhemba e Milho, em cultivo puro e consociação

Abstract

This work was conceived with the objective of determining the effect of different levels of water deficit during the growing cycle, on the yield of peanut, cowpea and maize crops in pure cultivation and intercropping. Data from an experiment conducted in the experimental field of irrigation and drainage of FAEF, from 11/09/1999 to 5/04/2000, which followed the design in subdivided plots with 4 replications, 4 crop treatments (pure crops) were used. peanuts, cowpea, maize and intercropping) and 3 irrigation treatments; one treatment without water deficit (Ri), one treatment with mild water deficit (R2), and one treatment with high water deficit (R3). The water deficits corresponded to the application of 67% (R2) and 33% (R3) of the water level of the treatment without water deficit (Ri), and were simulated with the Cropwat program. The maximum crop water consumption (ETm) was derived from the Rj treatment; the actual intakes (ETr) were derived from treatments R2 and R3, and were obtained with Cropwat. In the peanut crop, the ETm was 445.7 mm, while the ETr values ​​were 445.7 (R2) and 442.3 (R3) mm. For cowpea, ETm was equal to ETr, whose value was 571.6 mm. In the case of corn, the ETm was 444.8 mm, and ETr 444.8 and 442.7 mm, respectively. The maximum crop yields (Ym) were obtained from the treatment without water deficit, and the real yields (Yr) from the treatments with water deficit. ETo was determined by the modified Penman (Penman/FAO) and Hargreaves methods. Income was statistically analyzed using the SAS software. For each crop and each irrigation treatment, the mean yields were compared using the Duncan test at 5% probability, with no significant differences being detected between treatments Ri and R2 in the three cultures in pure cultivation and in the intercropping peanut. However, significant differences were detected only for cowpea and maize in intercropping. The land equivalence indices (LER) obtained in each irrigation treatment indicated an advantage of intercropping over pure crops of 390% for Rt (LER = 4.9), 250% for R2 (LER = 3.5) and 200% for R3 (LER = 3.0). The highest partial indices of land equivalence in the same irrigation treatments were obtained with cowpea Rj (3.14), R2 (1.88) and R3 (1.48), suggesting that this crop was the main component influencing the final yield of the system of cultivation. Regardless of the irrigation treatment, peanuts did not benefit from intercropping, resulting in low LER values, 0.22 (Ri), 0.21 (R2) and 0.20 (R3). Intercropping improved the water consumption of cowpea and maize crops, resulting in higher yields compared to pure crops, unlike peanuts (TRADUÇÃO NOSSA)