Study on the Relationship between Soil Element Change and Yield of Soda Saline-Alkali Paddy under Water-saving Condition

The yield of paddy and the determination of nitrogen, phosphorus and potassium in soil after harvest were obtained by the water saving treatment of paddy cultivated in soda saline-alkali soil. The result showed that in the harvest period, the total nitrogen was the highest in treatment 4, the total potassium was the highest in treatment 1, and the total phosphorus was the lowest in treatment 3. Fast nitrogen, phosphorus and potassium were the highest in treatment 1. The yield of treatment 2 was the highest, indicating that water saving at paddy tillering stage was beneficial to the absorption and transportation of nitrogen, phosphorus and potassium in soda saline-alkali soil. There was no significant correlation between soil total nitrogen and phosphorus and yield. Treatment 3 was significantly related to total phosphorus, treatment 1 was significantly related to total potassium, and treatment 3 was significantly related to fast potassium, implying that water saving had an important effect on the absorption of nitrogen phosphorus and potassium and its transport in paddy at different stages. The water saving period and water saving amount(1.5 cm) of treatment 2(tillering stage) were the water saving treatments for high yield of paddy cultivated in soda saline-alkali land. In this study, the relationship between the nutrient elements and the yield of different water-saving soil properties was analyzed in the experiment of water saving cultivation in the saline alkali land of Songnen Plain, which would be of great significance to the theoretical and technological research on high yield cultivation of rice ecological water saving and high yield cultivation.