Effects of cultivation patterns on rice yield and soil properties in cold waterlogged paddy fields

To find out the influence of different cultivation patterns on cold waterlogged paddy fields, the production potential of cold waterlogged paddy field was analyzed. The experiment was conducted in cold waterlogged paddy fields using the conventional tillage as the CK in contrast to the patterns of ridge culture (T1) and rice-fish (T2). The effects of different patterns on rice yield, and soil temperature, pH, and contents of aggregates, organic matter, reducing substrate, and enzyme activity were investigated. Results showed that compared with the control (CK), T1 significantly reduced soil micro-aggregate (<0.25 mm) content, enhanced the formation of large aggregates, improved soil temperature, increased soil organic matter, improved soil pH, inhibited soil ferrous rise after rice tillering stage, reduced soil manganous content, reduced rice root toxicity, enhanced soil enzyme activity and increased available nutrients contents of soil. Large aggregates (>1 mm) and organic matter content increased respectively by 67.6% and 28.0% at rice maturity stage. Treatment T2 had less effect on soil physical and chemical properties in cold waterlogged paddy fields. However, it significantly increased soil available nutrients (mainly available potassium and phosphorus) contents. Soil available potassium content increased 18.2% and 69.2% at booting and mature stages, compared with CK. It provided good soil environment and nutrition for rice growth, promoted rice growth and development, and improved rice yield. Further analysis showed that treatments T1 and T2 significantly improved rice yield in cold waterlogged paddy fields and increased yield in the range of 8.8%-25.8%. The effect of T1 on increasing rice production was the most significant, with actual output reaching 7 623 kg·hm^-2. In conclusion, treatment T1 effectively improved soil properties in cold waterlogged paddy fields and increased rice yield. The effect of increasing production of treatment T2 was mainly drived by increased water and soil available nutrients in cold paddy waterlogged fields.