Climate Change Affects Crop Production Potential in Semi-Arid Regions: A Case Study in Dingxi, Northwest China, in Recent 30 Years

Crop production potential (CPP) is profoundly affected by the change in climate factors (e.g., precipitation, temperature, and solar radiation) brought about by climate change, which ultimately affects the quantity and yield of crops. In China, arid and semi-arid regions are mainly located in the western regions and occupy around 59% of the land area. In order to identify the most important climatic factors restricting the increase in CPP and planting systems in the arid and semi-arid regions of northwest China, the changes in climate factors, CPP, and their correlation and planting systems were analyzed based on a representative semi-arid location, Dingxi, of Gansu province, from 1989 to 2019. The results showed that the temperature and precipitation increased by 0.89 °C and 26.61 mm, respectively, whereas solar radiation decreased by 5–6 d. The standard CPP of five crops (wheat, corn, potato, Chinese herbal medicines, and vegetables) increased by 655.09 kg/ha (1.09-fold), and precipitation played a more important role in improving CPP than other climate factors. Although there were positive correlations between the standard CPP and the five crops’ actual yields, no significant relationships were observed. The total cultivation area of the five crops showed a 215.55 × 103 ha (1.75-fold) increase with a 8.91-, 2.33-, 8.73- and 3.10-fold increase for corn, potato, Chinese herbal medicines, and vegetables, respectively, plus a 2.58-fold decrease for wheat. The agricultural ecosystem’s adaptability presented an obvious increase, especially from 2013 to 2019, although the agricultural natural environment factor maintained a low level. These findings provide scientific and technological support for the adjustment of planting structure, optimization of agricultural arrangement and development of water-saving agriculture in arid and semi-arid regions of northwest China.