磷肥滴施条件下土壤温度对棉花生长的影响 postprint

Abstract: This study examines cotton growth affected by soil temperature under the condition of phosphate fertilizer drip application. It also explores the role and mechanism of soil temperature regulation of cotton root growth on improving the utilization rate of cotton phosphate fertilizer. Using potted tests, three soil temperature gradients were examined: low temperature (LT: 11℃–18℃); medium temperature (MT: 22℃–26℃); and high temperature (HT: 30℃–34℃). Single factor testing with water bath temperature control was utilized. The effects of various soil temperatures on the growth traits, biomass, root distribution, effective soil phosphorus distribution, and phosphate utilization efficiency in cotton were assessed. As soil temperature increased, cotton plant height, stem thickness, leaf number and biomass all showed parabolic changes that peaked in the medium temperature (22℃–26℃) group. Additionally, root length in the 0 to 5 cm soil layer increased with soil temperature, most notably with high temperature treatment, followed by low temperature and medium temperature treatments increasing by 5.2%–126.9% and 4.9%–62.3%, respectively. Below the 5 cm soil layer, root length decreased with increasing temperature, with the medium temperature treatment having the longest root length, 81.68%–98.43%, which was 170.17%–218.35% longer than the low temperature and high temperature treatment, respectively. The effective P content of each treatment increased with lower temperatures, with the medium and high temperature treatment content being 13.7% and 20.5% lower than the low temperature treatment, respectively. Phosphorus absorption and phosphate utilization were maximized in the medium temperature cotton, followed by the low temperature cotton. With the lowest high temperature , the total phosphorus absorption in the medium temperature cotton increased relatively by 49.69% and 89.36% compared with low temperature and high temperature treatments, respectively. Furthermore, the phosphate utilization rate was twice and 50% higher than the high and low temperature treatments, respectively. These findings indicate that based on the effects of soil temperature on cotton growth, root and soil effective phosphorus distribution, phosphorus absorption, and phosphate utilization, the most suitable soil temperature for cotton growth is 22℃–26℃.