Effects of simulated warming and precipitation change on growth characteristics and grain yield of spring wheat in semi-arid area

In order to explore and validate the impact of further climate change on spring wheat growth and yield, and to obtain basic features of spring wheat's response to warming and precipitation change, an infrared temperature-increasing simulation experiment was conducted in Dingxi of Gansu Province, Northwest China. With the applications of free air temperature increased system (FATI) and water control devices, different precipitation and air temperature gradients were installed to simulate the effects of climate change on spring wheat growth. The impacts of warming and precipitation change on growth and yield of spring wheat were also analyzed. The results showed that warming of 2℃ decreased the plant height of spring wheat by 8.55% under normal precipitation condition, and warming of 2℃ decreased the plant height of spring wheat by 9.65% under the condition of increasing precipitation by 30%. Increasing precipitation by 30% enhanced the plant height of spring wheat by 4.8% under normal temperature condition, and increasing precipitation by 30% enhanced the plant height of spring wheat by 3.56% under warming of 2℃. The plant height of spring wheat under the condition of warming of 2℃ and increasing precipitation by 30% was smaller than that under normal temperature and normal precipitation condition. On the condition of normal precipitation, warming of 2℃ decreased the leaf area index of spring wheat by 28.15%, and on the condition of increasing precipitation by 30%, warming of 2℃ decreased the leaf area index of spring wheat by 31.04%. Under normal temperature and warming of 2℃, the effect of precipitation on leaf area index was not very obvious. The leaf area index of spring wheat under warming of 2℃ and increasing precipitation by 30% condition was smaller than that under normal temperature and normal precipitation condition. Warming decreased chlorophyll content of spring wheat leaf, and especially after filling stage, the chlorophyll content decreased more significantly. Increasing precipitation by 30% enhanced the chlorophyll content of spring wheat leaf under warming of 2℃. On the conditions of normal precipitation and increasing precipitation by 30%, the dry matter amounts of spring wheat under warming were all smaller than that under normal temperature. Increasing precipitation by 30% was conducive to the accumulation of dry matter under normal temperature and warming. In the vegetative growth stage and reproductive growth stage, under the conditions of normal precipitation and increasing precipitation by 30%, warming had a negative effect on the partition coefficient of the leaves and a positive effect on the partition coefficient of the stem, but increasing precipitation by 30% had a positive effect on the partition coefficient of the leaves and a negative effect on the partition coefficient of the stem. In the reproductive growth stage, under the conditions of normal precipitation and increasing precipitation by 30%, warming had a negative effect on the partition coefficient of the panicle, but increasing precipitation by 30% had a positive effect on the partition coefficient of the panicle. Under normal temperature, increasing precipitation by 30% enhanced yield of spring wheat by 4.89%, spikelet number by 4.92%, grains per panicle by 2.44%, grains weight per panicle by 4.99%, 1000-grain weight by 2.64%, length of panicle by 8.66% and weight of panicle by 4.92%. Under normal precipitation, warming of 2℃ decreased yield of spring wheat by 43.26%, spikelet number by 13.11%, grains per panicle by 15.85%, grains weight per panicle by 27.11%, 1000-grain weight by 13.54%, length of panicle by 14.96% and weight of panicle by 24.93%. Water addition had a positive effect on the yield of spring wheat, while warming did not help to improve the yield of spring wheat; even in the case of increasing precipitation, warming still had an adverse effect on yield. The research results can give the theoretical references for the sensitivity and adaptability of spring wheat in semi-arid area of China under global climate change. ©, 2014, Chinese Society of Agricultural Engineering. All right reserved.