Abstract: Taking different cotton cultivars with different maturity stage as test materials, a field experiment of two sowing dates and three N application rates was conducted in the lower reaches of Yangtze River basin (Nanjing and Huai’an) and Yellow River basin (Xuzhou and Anyang), with the effects of cultivar, main meteorological conditions, and N application rate on the cottonseed protein and oil contents analyzed, aimed to understand the quantitative relations of cottonseed protein and oil contents with environmental factors. Besides cotton cultivar, the major factors affecting the cottonseed protein and oil contents were in the sequence of the mean air temperature at bolling stage, solar radiation, and N application rate. The optimum mean air temperature for the production of cottonseed protein and oil at bolling stage was 26.1 ℃ and 25.7 ℃, respectively. Sufficient illumination did not favor the enhancement of cottonseed protein and oil contents. Increasing N application rate increased the cottonseed protein content but decreased the cottonseed oil content. Based on the statistical analyses, an ecological model for predicting cottonseed protein and oil contents was established, taking cultivar, mean air temperature and solar radiation at bolling stage, and N application rate as the input parameters, being easy to be operated. The root mean square error (RMSE) of the prediction of cottonseed protein content and oil content by the model was 2.03% and 2.54%, respectively, showing a good predictability of the model.

Key words: Yangtze delta, Agricultural production, Spatial disposition, Spatial transfer