Effect of different amendments on improvement and wheat yield of soil and wheat growth in “non-grain production” re-tillage Lei bamboo forest land

<bold>Objective</bold> Long-term ‘non-grain production’ utilization of cultivated land has caused severe soil acidification，which seriously restricts the safe production of grain in re-tillage land.Rational application of lime-based conditioners and biochar can effectively address soil acidification. <bold>Method</bold> A field experiment was conducted on Lei bamboo forest reforested farmland in Taihuyuan Town，Lin’an City，Zhejiang Province.A total of ten treatments were designed：no amendment（CK），three lime application levels of 1.5（L₁），3（L₂），4.5（L₃）t/hm²，three rice husk biochar application levels of 3（B₁），6（B₂），9（B₃）t/hm²，three limestone powder application levels of 3（LP₁），6（LP₂），9（LP₃）t/hm².In this study，a field experiment was conducted to study the effects of different application techniques of lime，rice husk biochar and limestone powder on soil physical and chemical properties，wheat growth and grain yield， thus providing theoretical basis and technical support for efficient acid reduction and quality improvement of acidified soil in ‘non-grain production’ re-tillage land and improvement of wheat yield. <bold>Result</bold> The application of lime and limestone powder amendments significantly increased the soil pH at the regreening stage and mature stage of wheat，and the effect was better than that of biochar amendments.Under the current experimental conditions，with the increase of lime and limestone powder dosage，the improvement effect of acid remedy also increased.The effect level of three modifiers on improving soil available nitrogen，available phosphorus and available potassium ranking from high to low was biochar，limestone powder and lime respectively.Compared with the control without amendment（CK），the three amendments of lime，rice husk biochar and limestone powder all positively contributed to the absorption of total nitrogen，total phosphorus and total potassium in wheat plants.However，the effectiveness of different amendments on nutrient absorption by wheat were different.The ability of applying biochar and limestone powder to increase the total nitrogen content of wheat was stronger than that of lime.The application of limestone powder had a better effect on the total phosphorus content of wheat，and the application of biochar had a more significant effect on the total potassium content of wheat.Moreover，the application of three amendments increased grain ear weight，1 000-grain weight and grain yield of wheat to a certain extent.The effect level of increasing wheat grain yield ranking from high to low was biochar，limestone powder and lime.The treatment with biochar application rate of 6 t/hm² had the best effect on increasing wheat grain yield，followed by the treatment with biochar application rate of 3 t/hm².Correlation analysis showed that soil available nutrients had a significant effect on wheat nutrient absorption.Among them，soil available potassium also had a significant correlation with wheat yield. <bold>Conclusion</bold> Based on the effects of soil fertility，crop yield and safety application dosage，biochar amendment was more effective than lime and limestone powder in improving the content of available nutrients in the soil of ‘non-grain production’ re-tillage land.At the same time，biochar amendment had a significant positive effect on wheat nutrient absorption and yield.Therefore，the rational application of low and medium rates of biochar is expected to provide an effective way for the healthy production of ‘non-grain’ re-cultivated soil.