Water Requirement of Solar Greenhouse Tomatoes with Drip Irrigation under Mulch in the Southwest of the Taklimakan Desert

Abstract

Understanding crop water requirements is important for establishing irrigation schedules, and improving water use efficiency (WUE), crop yield and crop quality. In order to reveal the optimal water requirement of tomatoes in various growth stages, the responses of the water requirement, crop coefficient, fruit yield and quality of tomato to different irrigation levels were studied in a solar greenhouse in Hetian, Southwestern Taklimakan Desert, China from August 2019 to June 2020. The medium irrigation quota (Ia) was calculated in different tomato growth stages based on the root distribution range, suitable soil moisture content of high yield, and the planned wetted percentage of drip irrigation. Five irrigation levels (60%, 80%, 100%, 120% and 140% Ia) were used. The technique for order preference by similarity to ideal solution (TOPSIS) results showed that 120% Ia was the optimal irrigation quota for the yield, water use efficiency (WUE), and fruit quality of tomato. The daily water requirement of 120% Ia were 2.26, 4.28, and 2.35 mm·d−1 in three growth stages in the autumn–winter season, while it was 1.96, 3.99, and 3.80 mm·d−1 in the winter–spring season. The crop coefficients of the three stages in each growth season were 0.49, 1.10, and 0.76, and 0.61, 1.09, and 0.78, respectively. The results could provide guideliens for improving the productivity of protected agriculture in the Southwestern Taklimakan Desert or other similar regions.