Actual impacts of global warming on winter wheat yield in Eastern Himalayas

Document Type: Research Paper

Authors

1 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology & Ecology, Ministry of Agriculture, Beijing 100081, China.

2 Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, China

3 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology & Ecology, Ministry of Agriculture, Beijing 100081, China

4 Tibet Vocational Technical College, Lhasa 850000, China

5 Institute of Agricultural Sciences of Lhasa, Lhasa 850000, China.

Abstract

Himalayas, are among the areas most vulnerable to global warming, however, little is known
about warming impacts on the crops. Therefore, the actual affects of anticipated warming on
winter wheat were tested in Tibet, China. During the period 1988-2012, Tibet region has
experienced a large increase in daily mean, minimum and maximum temperatures during wheat
growing seasons by 0.50, 0.67 and 0.51 oC every ten years, respectively. The de-trended wheat
yield increased by 34.4 kg ha-1 year-1 during this period. According to the historical data, 1 oC
increase in daily mean temperature could get 370.6 kg ha−1 gain in wheat yield. Similar gains in
wheat yield were found in a field warming experiment with an increase of 1.1 oC in daily mean
temperature. The field warming caused a significant reduction in the pre-anthesis phase and
entire growth period by 14 and 13 days, respectively. The green leaf areas and spike number in
the warmed plots were significantly higher than that in non-warmed plots, while the grain
number per spike was significantly lower in the former than the later (P<0.05). The main
mechanism underlying the positive affects of this moderate warming on wheat yield is through
improving plant development and growth during the pre-anthesis phase by mitigating the low
temperature limitation. This study suggests that further efforts should be directed towards the
improvement on agriculture infrastructure to utilize the positive affects of climatic warming on
crop production.


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