Irrigação real necessária em cafeeiro conilon: estudos metodológicos

Abstract

With the increasing use of irrigated agriculture in Brazil, the availability of water becomes one of the main physical factors that directly influence the development and production of agricultural crops. The State of Espírito Santo is the largest national producer of Conilon coffee (Coffea canephora), however the water deficit still limits productivity per hectare, acting in a negative way in the crop. In this sense, the management of irrigation seeks to fill the gaps left by the act of how much and when to irrigate, having as pillar the storage of water in the soil and the water expenditure of culture. Therefore, management can be carried out through the knowledge of the water content in the soil or through climatic data of a given region. The objective of this work was to evaluate the reference evapotranspiration estimate by the methods of Penman-Monteith FAO 56 and Hargreaves-Samani obtained from climatic data from a local automatic weather station (EMAL) and an automatic weather station from Inmet (EMAI) to a distance of 5.0 km, and also the soil moisture measured by the TDR, with the standard greenhouse thermogravimetric method in the irrigation management of the conilon coffee. The study was carried out in an adult crop of Coffea canephora, variety “Conilon Vitória Incaper 8142”, belonging to the Federal Institute of Espírito Santo - Campus de Alegre, where soil moisture was detected by the TDR apparatus and by the Electric Greenhouse methodology. The replacement of water in the fields was done via TDR, with a fixed irrigation shift of 4 days, totaling 18 irrigation events analyzed. The estimated coefficients for the correction of the evapotranspiration of the adult conilon coffee by virtue of the reference evapotranspiration method, were as follows: 1.14 and 1.02 for PenmanMonteith; and 0.82 and 0.85 for Hargreaves-Samani. Penman-Monteith underestimated the IRN by 0.56 mm d-1 and Hargreaves-Samani overestimated the same variable by 1.08 mm d-1, when they were obtained from EMAL climatic data; and when using EMAI climatic data, Penman-Monteith underestimated IRN by 0.09 mm d-1 and Hargreaves Samani overestimated by 0.76 mm d-1 compared to the Greenhouse. Penman-Monteith obtained a performance rating of “good” for both seasons and Hargreaves-Samani “bad” for EMAL and “average” for EMAI. TDR achieved the best performance in relation to Penman-Monteith and Hargreaves-Samani, obtaining the “great” rating.