关键词: 生态安全, 生态安全, 综合评价, PSR模型, 都市农业, 珠三角

Abstract: In order to clarify the suitable sowing date and planting density for wheat under wide belt planting in the area along the Yangtze River in Jiangsu Province, a vernal wheat variety‘Yangmai 13’was used as the material and a field experiment with split plot design was conducted to study the effect of sowing date and planting density on grain yield and its components of vernal wheat with 20 cm drilling width and 40 cm spacing intervals. The results showed that the effects of sowing date and density onkernels per spike and thousand seed weight were not significant, but their effects on spike number of unit area and grain yield were significant.The average yield of wheat sown on October 26 was the highest, the average yield of wheat sown on November 5 and 15 reduced by 5.98% and 19.50% compared with that on October 26, and the average yield of wheat sown on November 15 reached a highly significant difference. The average yield of wheat of the planting density of 3 million and 3.75 million seedlings per hectare had no significant difference, but were significantly higher than that of 1.5 million and 2.25 million seedlings per hectare. According to the analysis of sowing date and planting density, October 26 to November 5 was the suitable sowing period, and the corresponding density was 3 million to 3.75 million seedlings per hectare.