Interactive effects of biochar and organic fertilizer substitution on soil nutrient dynamics and wheat growth

Background Organic fertilizers are natural substances used to enrich soil and provide nutrients to plants. Which can enhance soil fertility and reduce chemical fertilizer application, while biochar, as a soil amendment, can promote plant physiological parameters. Under the premise of organic fertilizer application, it remains unclear whether the application of organic fertilizers and biochar affects soil fertility. Methods In this pot experiment, a two-factor randomized complete block design was adopted, with each pot filled with 1.5 kg of air-dried soil. The fertilization factor included 6 treatments: no fertilizer (FO), chemical fertilizer (FCF), 100%, 50% and 25% organic fertilizer replacing nitrogen fertilizer (F100OF, F50OF, F25OF), respectively. While 20% reduction were showed in chemical fertilizer application (F80CF). The biochar application rate was set at 3 levels (30, 15, and 7 g pot ^− 1 ). The experiment aimed to explore the effects of these combined treatments effects on wheat growth and soil properties. Results In our study the results showed that with application of 30 g biochar, as compared to no fertilizer treatment. The soil organic matter and available potassium contents were increased by 57.74%–183.47% and 64.14%–99.90%, respectively. On the other hand, when the 30 g biochar was applied, then phosphorus contents and potassium contents in root and shoot parts of wheat increased by 34.50%–72.10% and 49.12%–102.66%, respectively. Further biochar 15 g application, the total nitrogen content and phosphorus content in the root and shoot parts increased by 32.09%–62.46% and 27.09%–52.73%, respectively. At the end when the with application of biochar 30 g, as compared to no-fertilizer treatment, the plant height significantly increased by 40.62%–56.32%, while the root and shoot dry weight significantly increased by 86.63%–124.26% and 33.33%–73.81%, respectively. Conclusion Consequently, the optimal recommended fertilization regime is "50% organic fertilizer replacing nitrogen fertilizer + 30 g biochar. The soil quality is improved and wheat exhibits a more favorable nutrient absorption, and reduce chemical fertilizer application, and further provide a theoretical basis for the healthy and sustainable development of agriculture.