Effects of precipitation and air temperature changes on yield of several crops in Eastern Gansu of China

Abstract

Investigating the response of crop production to climate change can help to optimize local agricultural practices, and then ensure food and ecological security. Crop models can provide a useful way to examine the effects of a range of climatic condition, management or crop cultivar on crop growth and yield in field and pasture. This work investigated the effects of precipitation and air temperature changes on the production of winter wheat, maize and lucerne in rain-fed agriculture area located in the central and western Loess Plateau by field experiment and crop simulation model. The field experiment was conducted at Qingyang Loess Plateau Experimental Station of Lanzhou University through 2001 to 2010, and the Agricultural Production Systems Simulator (APSIM) was applied in this study to simulate the growing process of winter wheat, maize and lucerne. The APSIM was validated with the experimental data firstly, and then the APSIM was applied to simulate the yield variability of the crops under the combinations 5 precipitation levels and 5 air temperature levels based on historical climatic data from 1961 to 2010. Temperature levels were: 1) -1.5 decrease in daily mean temperature (T1); 2) -1 decrease in daily mean temperature (T2); 3) historical daily temperature (T2); 4) 1 increase in daily mean temperature (T4); and 5) 1.5 increase in daily mean temperature (T5). Precipitation levels were: 1) 20% decrease in daily precipitation (P1); 2) 10% decrease in daily precipitation (P2); 3) historical daily precipitation (P3); 4) 10% increase in daily precipitation (P4); and 5) 20% increase in daily precipitation (P5). Results showed that the APSIM can predict the grain yield and biomass of the 3 crops accurately with the determination coefficients varied between 0.80-0.93, the normalized root mean square errors varied between 11.35%-22.48%, and the model efficiency varied between 0.53-0.91; Overall, APSIM was powerful to simulate the crop grain yield and biomass of winter wheat, maize and lucerne in study site. Winter wheat and lucerne maintained the greatest yield increase when the air temperature decreased and the precipitation increased during 1961-2010, which was 29.8% and 51.7%. Maize reached its greatest yield, which improved 22% when the precipitation increased and the air temperature remained unchanged. The maximal reduction of yield of 3 crops were 38.7%, 40.3% and 41.8%, respectively, which presented in the scenarios with low precipitation level and high temperature level. In addition, the variation range of winter wheat yield was reduced by increasing air temperature and precipitation while lucerne yield exhibited a smaller variation range when precipitation decreased and temperature increased. According to the trend of winter wheat and lucerne, the variation range of maize yield tended to boost by increasing precipitation, otherwise, maize yield also showed a wider range under the temperature level varied from T1to T3; but when temperature level hoisted up the T5, variation range of maize yield tended to be narrower. Overer, lucerne could adapt to the climate change better than winter wheat and maize with relatively inferior changes of yield variation under different climatic scenarios. In conclusion, the 3 crops were more sensitive to precipitation and they had positive linear relationships with precipitation level by slopes of 14.3-16.0, 11.8-15.5 and 15.0-18.9, respectively. The results should offer better comprehension and consultation for future studies and actual production about long-term of chief crop production when climate changes. Future agricultural production should attach importance to change crop management such as sowing date and cultivar to avoid heat or moisture stress. Otherwise, more efforts should be paid to explore the effect of interaction by CO2, solar radiation, precipitation and air temperature on crop production on the western of Loess Plateau. © 2016, Chinese Society of Agricultural Engineering. All right reserved.