[Effects of supplemental irrigation by measuring soil moisture on water consumption chara-cteristics and radiation...

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.