Yield and water productivity of rice grown under different irrigation methods

Abstract

The aim of the study was to investigate the suitability of subsurface and surface drip irrigation methods in rice farming. The field studies were carried out in split plots in randomized blocks trial design, with three repetitions during 2019 and 2020 in Thrace Region/Turkiye. Irrigation methods, surface drip (DI), subsurface drip (SDI) and conventional flooding (CF) were the main treatments; however, water amounts (I1: Class A-pan evaporation rate x 1.00, I2: Class A-pan evaporation rate x 1.25, I3: Class A-pan evaporation rate x 1.50) were designed as sub-treatments of the study. The results of the statistical analyses indicated that, the rice grain yield was significantly (P < 0.01) affected by the amount of the irrigation water. According to the results; while two different drip irrigation methods did not make a difference to yield and yield components, the difference between drip irrigation and CF was significant (P < 0.01). While the grain yields reached 10.3 and 8.70 t/ha under conditions of CF control during 2019 and 2020, the highest yield values obtained from plots with drip irrigation system and the highest Class A-pan evaporation rate x pan coefficient of 1.50 were 8.10 and 6.90 t/ha during the same two study years, respectively. However, much more effective use of water was observed under conditions of drip system application providing approximately 60-70% water saving v. 20-25% yield loss. In addition, economic analysis results indicated a higher relative profit rate of 1.66 in the case of drip irrigation than 1.41 under CF application.