Effects of supplemental irrigation by measuring soil moisture on water consumption chara-cteristics and radiation utilization in wheat

Abstract

Field experiments were conducted during 2013-2014 and 2014-2015 winter wheat growing seasons by using Jimai 22 as test material. Five treatments were designed: W0(non-irrigation during growth season), W1(non-irrigation at overwintering, but irrigated to 65% of field capacity (FC) at jointing and 70% of FC at anthesis in 0-40 cm soil layer), W2(irrigated to 70% of FC at overwintering, 65% of FC at jointing and 70% of FC at anthesis in 0-40cm soil layer, respectively) and W3(irrigated to 75% of FC at overwintering, 65% of FC at jointing and 70% of FC at anthesis in 0-40cm soil layer, respectively), W4(irrigated 60 mm at overwintering, jointing and anthesis stages, respectively). The aim was to clarify the effects of supplemental irrigation on water consumption characteristics and photosynthetically active radiation utilization in wheat. Results showed that the total irrigation amount and its ratio to total water consumption in each treatment were ranked as W4＞W3＞W2＞W1＞W0. However, the percentage of water consumption in soil to total water consumption was presented as W0＞W1, W2＞W3, W4. The total water consumption, water consumption from anthesis to maturity were ranked as W4＞W2, W3＞W1＞W0. The order of photosynthetically active radiation (PAR) capture ratio was W4＞W2, W3＞W1＞W0, but the order was contrary in PAR reflect ratio among the treatments. The net accumulation of dry matter was ranked as W4＞W2＞W3＞W1＞W0 in the two growing seasons. During the two winter wheat growing seasons, the grain yield in W2 was higher than in the other treatments, except W4, but the irrigation efficiency and water use efficiency in W2 were the highest. Concerning both the high-yield and high-water use efficiency in this experiment, the most appropriate irrigation regime was W2 treatment.