Carbon sequestration and nutrients improvement meditated by biochar in a 3-year vegetable rotation system

Purpose Intensive cultivation is an agrotechnology that has become highly popular among farmers around the world. However, carbon (C) loss and nitrogen (N) loss are found because of intense and year-round crop production, high N-fertilizer application, higher temperatures and frequent irrigation in intensive cultivation system. Biochar is a more practical and suitable strategy to enhance soil quality in plastic shed. The purpose of the present study was to understand how to manipulate biochar-induced changes in soil properties. Materials and methods A consecutive 3-year field experiment was performed in experimental cells amended with four different dosages of straw biochar (0, 10, 20, and 40 Mg ha −1 ). The soil carbon characteristics and physicochemical properties were determined. Results and discussion The soil organic carbon (SOC) contents increased by 8.5–47.5% after once initial straw biochar application, which owing to the recalcitrant nature of biochar. The SOC contents gradually decreased by 4.8–35.8% after 3 years, because biochar owned the labile carbon fraction. The mechanisms that carbon contents in the proportion of micro-aggregates (< 250 µm) increased by 81.3–89.6%, while that of macro-aggregates (> 250 µm) decreased by 59.4–73.4% after straw biochar application resulted the carbon easily oxidized organic carbon content by 3.8–25.9%. The Electrical Conductivity, available phosphorus, and available potassium in the soil samples were enhanced by 5.9–19.3%, 6.0–14.9%, and 47.5–148.4%, respectively, after biochar application. The adsorption of biochar ensured the nutrient contents to be retained in the soil. Conclusions Field studies help in better prediction of the effects of biochar addition on soil C sequestration and soil nutrients cycling. The parameters are important when investigating the extent of the effects of soil biochar amendment for vegetable rotations in plastic shed. The 20 Mg ha −1 straw biochar could be an appropriate dosage for vegetables cultivation to meet the purposes of carbon storage and nutrient retaining.