棉 花 学 报 Cotton Science 2006，18(6)：362-366
Seasonal Changes of Salinity and Nutrients in the Coastal Saline Soil in Dong-ying，Shandong，and Their Effects on Cotton Yield Abstract：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 low-yielding 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. Potted 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. |