The complex impacts of climate change on crop growth and yield are confounded by changes in cultivars and agronomic management. To accelerate understandings of climate impacts, among other things, the relative contributions of cultivars, agronomic management and climate change to crop yields change need to be disentangled.
TAO Fulu’s group from the Institute of Geographic Sciences and Natural Resources Research (IGSNRR)，Chinese Academy of Sciences used the detailed field experiment data from 1980 to 2009 at four stations in the North China Plain (NCP), together with a crop simulation model, to disentangle the relative contributions of cultivars renewal, fertilization management and climate change to winter wheat yield, as well as the relative impacts of different climate variables on winter wheat yield, in the past three decades.
The results showed that during 1980–2009 cultivars renewal contributed to yield increase by 12.2–22.6%; fertilization management contributed to yield increase by 2.1–3.6%; and climate change contributed to yield generally by -3.0 ？ +3.0%, however by -15.0% for rainfed wheat in southern part of the NCP. Modern cultivars and agronomic management played dominant roles in yield increase in the past three decades, nevertheless the estimated impacts of climate change on yield accounted for as large as -23.8 ？ +25.0% of observed yield trends.
During the study period, increase in temperature increased winter wheat yield by 3.0–6.0% in northern part of the NCP, however reduced rainfed winter wheat yield by 9.0–12.0% in southern part of the NCP. Decrease in solar radiation reduced wheat yield by 3.0–12.0% across the stations. The impact of precipitation change on winter wheat yield was slight because there were no pronounced trends in precipitation.
The findings highlight that modern cultivars and agronomic management contributed dominantly to yield increase in the past three decades, nevertheless the impacts of climate change were large enough in some areas to affect a significant portion of observed yield trends in the NCP.
The work is highlighted by European Society for Agronomy as
This paper is important for a number of reasons. First, China is an enormously important country with respect to food security with crucial implications for global food security. Secondly, this paper covers nearly 30 years of measurements in China and lastly a combination of modelling and observation is used in the analysis. The study is on a large enough scale that both positive and negative effects on wheat yield can be disentangled based on weather, climatic and agronomic factors. The authors deserve congratulations for their research focus, analytical ability and endeavours in producing such a fine paper for the EJA.
John Porter, EJA chief editor
