山东东营滨海盐渍棉田盐分与养分的季节性变化及对棉花产量的影响

Seasonal Changes of Salinity and Nutrients in the Coastal Saline Soil in Dong-ying,Shandong,and Their Effects on Cotton Yield

在山东省东营市选择土壤盐分含量分别为0．15％、0．35％和0．50％的高、中、低产田各一块，种植中早熟品种鲁棉研18或早熟品种鲁棉研19，结合取盐碱土盆栽，研究了不同含盐量棉田的盐分、养分含量变化及棉花产量表现。结果表明，高产田有机质与碱解氮含量较高、有效磷含量偏低、有效钾含量中等，而低产田则表现出有机质少、贫氮、缺磷、富钾的特点。三类棉田的土壤盐分皆是春季和秋季高、夏季低，土壤有机质含量在整个生育季节内变化不大，而氮、磷、钾则随生育进程的推进呈逐渐减少的趋势。大田条件下，中、低产田比高产田分别减产10％～17％和27％～39％，而相应盐土盆栽条件下则分别减产2．8％和6．7％。

There has been a large area of coastal saline lands in Dongying city, Shandong Province, which is potentially to be reclaimed to develop cotton production. Therefore, investigation into the characteristics of plant growth and development, and the corresponding impact factors in saline soils is of great value to realize yield potentials of cotton in this area. Three types of fields with salt content of 0. 15%, 0.35% and 0.50% were selected as low-, middle-, and high-yielding cotton fields. Each field was planted with spring cotton variety SCRC 18 or short-season one SCRC 19 in 2005. Soils from corresponding fields were also potted and planted with SCRC 19 in Jinan in the same season as the field experiment. Seasonal changes of salinity and nutrients in the soils, and yield performance of each variety under either field or potted condition were examined. The results showed that the high-yielding field contained higher organic matter and effective N, and lower effective P than other two fields, but contained moderate level of effective K. Levels of organic matter, effective N and P were much lower, and effective K was significantly higher in lowyielding field than those of high yielding fields. Salt contents in the three types of fields were relatively higher in spring and autumn, but lower in summer. The level of organic matter in soil remained relatively stable through the growing seasons however, levels of effective N, P and K appeared to be decreased gradually as plant growth advances. Lint yields of the middle-,and low-yielding fields were decreased by 10%-17% and 27%-39%, respectively, compared to that of high yielding field. Pot ted plants in middle-, and low-yielding field soils produced lint 2.8 % and 6.7 % less than those in low- yielding field soil, respectively. Under field conditions, variation of lint yield among varying saline soils was not only attributed to the differed levels of salinity, but also to other impacting factors such as varying levels of soil organic matter and nutrients.