滨海盐碱地棉田耕层最佳水盐含量的确定及对棉花光合特性的影响
毕业论文关键词：滨海土壤，水埋深，光合特性
目 录
摘 要 1
关键词 1
Abstract 1
Key words1
引言 2
1 材料和方法 3
1.1 品种和地点概述、试验设计和棉花管理3
1.2 气象资料3
1.3 实际水埋深监测4
1.4 土壤样品收集和土壤相对含水量4
1.5 土壤分析4
1.6 叶面积、叶绿素含量、光合参数和叶绿素荧光参数测定4
1.7 数据分析5
2 结果5
2.1 水埋深5
2.2 水埋深对滨海棉田土壤水盐含量的影响5
2.3 土壤水盐含量对棉花光合特性的影响6
3 讨论 9
3.1 水埋深对滨海棉田水盐含量的影响9
3.2 土壤水盐含量对棉花光合特性的影响10
结 论 11
致 谢 11
参考文献 12
滨海盐碱地棉田耕层最佳水盐含量的确定及对棉花 (Gossypium hirsutum L.)光合特性的影响
Determination of optimum soil water and salt content and their effects of cotton (Gossypium hirsutum L.) photosynthesis in the plow layer of cotton field for coastal saline soil
Abstract：To target the favorable conditions for cotton growth in coastal saline soil, a two year field experiment was conducted in 2013 and 2014 by setting various environments for soil water and salt with different groundwater depths (0.6, 1.0, 1.4, 1.8, 2.2, 2.6 m in 2013 and 0.4, 0.8, 1.2, 1.6, 2.0, 2.4 m in 2014). Results showed that (1) in relatively arid year of 2013, soil exhibited normal soil-relative water content with high salt and mild drought with moderate salt in the optimal groundwater depth of 1.4 m and of 1.8 m, respectively. In relatively humid year of 2014, soil displayed normal soil-relative water content with low salt in the optimal groundwater depth of 1.6 m and 2.0 m. (2) Net photosynthesis, cotton yield and fiber quality all approached to the highest values in the optimal treatments. The reduction in net photosynthetic rate was mainly due to non-stomatal restriction in the treatment of 0.6 m in 2013 and 0.4 m in 2014. Meanwhile, in other treatments stomatal restriction was the main factor for photosynthesis limitations. In summary, the favorable soil-relative water contents for 0-20 and 20-40 cm soil depth were 54.68%-65.14% and 69.14%-79.13% in dry year of 2013 and 67.18%-69.39% and 73.00%-77.92% in humid year of 2014, respectively; similarly, electrical conductivity of a 1:5 distilled water for 0-20 and 20-40 cm soil depth was recorded as 0.92-1.20 dS m-1 and 0.70-0.95 dS m-1 in 2013, while 0.28-0.32 dS m-1 and 0.45-0.51 dS m-1 in 2014, respectively.