Effect of Surface and Subsurface Drip and Irrigation Level on Consumptive Use and Yield of Potato Under Gypsiferous Soil Conditions

Abstract

The objective of this study is to determine the consumptive use and yield of potato (Solanum tuberosum L.) and its relation with available soil water depletion ratio, surface (SD) and subsurface drip irrigation (SSD) under gypsiferous soil conditions. A field study was conducted in spring season on 2013 at experimental research station of Soil and Water Resources Department, College of Agriculture, Tikrit University. The experimental design was split plot with RCBD in three replications. Drip irrigation of SD and SSD represent main plots and depletion ratio of 35, 45, and 45% represent sub main plots. The treatments were T1, T2, T3, T4, T5, and T6, respectively. Rudolph variety of potato was planted on 3-2-2013 and harvested on 20-6-2013. Actual and reference evapotranspiration (ETC and ET0), water use efficiency (WUE), crop coefficient (KC), yield, leaf area index (LAI), and root weight density (RWD) were measured through growth season of potato. Results showed that ETc was 434.4 and 322.6 mm/season for T1 and T4, respectively, whereas it was 370.0, 308.2, 265.0 and 218.9 mm for T2, T3, T5 and T6, respectively. KC values of T1 were 0.52, 1.16, and 0.71 and for T4 were 0.38, 0.86, and 0.53 for vegetative growth, tuber initiation, and tuber bulking and maturation stages, respectively. Highest value of WUE (6.55 kg/m3) was obtained in T4. Significant increase in yield was found when depletion ratio increased from 35 to 45% for both SD and SDD. The highest yield, 14.93 and 17.35 ton/ha was found for T2 and F5, whereas the lowest yield, 12.03 and 13.5 ton/ha for T3 and T6, respectively. Highest value of LAI was 1.21 for T5, and RWD values significantly increased with increase in depletion ratio. They were 2.05 and 3.17 mg/cm3 for T3 and T6, respectively.