Influence of climate warming and rainfall reduction on semi-arid wheat production

Infrared simulations were conducted in semi-arid Dingxi, Gansu, Northwest China to investigate the influence of climate changes that result in increased temperatures and reduced rainfalls on spring wheat production. Spring wheat was grown in one of the following six simulations formed in a factorial arrangement of three ambient temperature changes (+0℃, +1.0℃ and +2.0℃) and two rainfallsnormal (W₀) and 30% below average (W₃₀):0-W₀, 0-W₃₀, 1-W₀, 1-W₃₀, 2-W₀, and 2-W₃₀. Wheat yield, biomass, panicle characteristics, plant height, leaf area, chlorophyll, and net photosynthetic rate in each simulation were obtained. Decreased rainfall reduced wheat grain yield by 24.41%, 12.93%, and 27.38%, and wheat biological yield by 19.25%, 10.31%, and 22.11%, for +0℃, +1.0℃, and +2.0℃, respectively. The decreases suggested that the impact of climate warming was especially unfavorable for the economical return of wheat production. Wheat grown with decreased rainfall was lower in panicle length and weight, total spikelet number, number of grains per panicle, weight of grains per panicle, and 1000-grain weight, and higher in sterile spikelet number and spikelet sterility rate. Wheat net photosynthetic rate, leaf area, and chlorophyll content were reduced as the ambient temperature was increased and rainfall decreased. Spring wheat growth and production were severely affected when the ambient temperature increased 1℃ to 2℃ and rainfall dropped 30% in semi-arid China, suggesting that it is important to develop adaptation cropping to climate changes.