Effects of plow tillage and different water and fertilizer management methods on the soil properties and rice yields of paddy under wheat straw returning

Toxic substances derived from returning wheat straw to paddy fields can adversely affect the growth of subsequent rice crops. Therefore, it is important to develop tillage methods and water and fertilizer management methods that mitigate the negative impacts of straw returning. Accordingly, the aim of the present study was to compare the effects of plow tillage and different water and fertilizer management methods on the physicochemical properties and rice yield of paddy fields. Field experiments involved eight treatments (control, fertilizer, straw, fertilizer+straw, plow tillage, water replacement, prolonged immersion, and prolonged immersion+postponed fertilizer). The phenolic acid content of the field surface water was effectively reduced by prolonged immersion. The nitrogen and phosphorus content of the field surface water was also significantly lower in the fields treated with straw returning and different water and fertilizer management methods than in the fertilizer-treated fields. The reasonable application of straw, especially under the plow tillage and water replacement treatments, could promote the growth of rice; as compared to the yields of rice grown under fertilizer and straw treatment alone, the addition of plow tillage and water replacement increased the number of effective spikes by 19.9% and 15.2%, respectively. In conclusion, the negative effects of wheat straw returning on rice growth could be effectively mitigated by a variety of methods, including plow tillage, water replacement, and prolonged immersion, which could further promote plant nutrient uptake and increase crop yield. Considering the comprehensive effects of environmental risk, plow tillage and prolonged immersion are better suited for situations in which wheat straw is returned to the paddy field.