Drip irrigation amount and plastic mulching affect soil hydrothermal properties, productivity and water use efficiency of cucumber in two contrasting environments

Abstract

Growing environment plays a major role in crop growth and performance, especially fruits and vegetables that are prone to hazardous environmental factors. Crops grown in open-fields are subjected to unstable evaporative demand of the atmosphere and disease infestation due to excessive rainfall. In contrast, protected structures such as greenhouse, poly-covered house, net house, among others, modify extreme climatic conditions and protect the crops. This study was conducted to compare some soil hydrothermal properties, cucumber performance and water use efficiency under different drip irrigation regimes and plastic mulch under open field and poly-covered house conditions, in southwest Nigeria, during the dry period of 2020/2021 growing season. Increasing drip irrigation water amount and plastic mulching significantly (p < 0.05) increased soil water content in both growing environments. Poly-covered house maintained soil water content within the crop root zone during the growing cycle, while water content varied in the open-field. Plastic mulching increased soil temperature by 0.3 to 1.0 ^oC in both 0 - 10 and 10 - 20 cm soil layers only in the open-field. Decreasing irrigation amount increased soil temperature in both soil layers in both growing environments. Plastic mulching increased cucumber yield components and water use efficiency while irrigation four times a week gave the optimum cucumber yield while fewer fruits and lower cucumber yield were obtained in the poly-covered house compared with open-field. The combination of plastic mulching and irrigation amount four times a week under open-field conditions are recommended for the cultivation of this variety of cucumber in this region.