Temporal-spatial variations of reference evapotranspiration in Anhui Province and the quantification of the causes. Temporal-spatial variations of ammonia and nitrate under application of inorganic and organic fertilizers in purple soil of winter wheat Temporal-spatial variations of net ecosystem productivity in alpine area of southwestern China Temporal-spatial variation of elongating time of wheat in Huang-Huai wheat production area Spatial variations of soil ammonia and nitrate under application of inorganic and organic fertilizers in purple soil—Summer corn season