Role of vermicompost and biochar in soil quality improvement by promoting Bupleurum falcatum L. nutrient absorption

Abstract

Bupleurum falcatum L. (B. falcatum) has gained the attention due to its medicinal value in its root. B. falcatum was continuously cultivated and intensively chemically fertilized in order to attain a high yield, which reduced the soil quality and caused continuous cropping problems. Thus, there is significant impact on S. baicalensis yield and quality. To solve this problem, soil with 0 or 3 continuous cropping years (0‐year and 3‐year soil) was fertilized with several organic materials, that are Bacillus subtilis, Bacillus mucilaginosus, humic acid fertilizer, biochar, and vermicompost. The experiment examined the effectiveness of B. falcatum's growth and nutrient uptake under various organic materials. It was shown that organic materials improved soil fertility and promoted the growth and nutrient uptake of B. falcatum. The combination of vermicompost and biochar had a better improvement effect. It increased soil nutrients by 23.8%~73.3% (0‐year soil) and 24.6%~71.1% (3‐year soil), respectively. In two types of soil, both microbial number and enzyme activity substantially increased. The B. falcatum shoot and root biomass with vermicompost was increased 74.8%~84.5% (without biochar) and 41.8%~71.1% (with biochar) in two different types of soil. Vermicompost and biochar also significantly promoted the root development of B. falcatum. The root length increased by 13.3%~66.7%, the root width by 38.6%~84.8%, the root volume by 8.4%‐61.3%, and the specific root length varied by ‐171.9%~3.1%; as compared to the control. The nutrient (N, P and K) concentrations in shoots and roots changed ‐3.9%~67.2% and 1.4%~53.5%, respectively. All the findings demonstrated that long‐term continuous cropping caused cropping obstacles, deteriorated soil quality, and enhanced the B. falcatum growth. Applying organic fertilizers, such as vermicompost and biochar, can help to improve soil quality, increase soil nutrients, promote the growth and nutrients absorption of B. falcatum, and eliminate continuous cropping obstacles.

Combined Application of Chemical and Organic Fertilizers: Effects on Yield and Soil Nutrients in Spring Wheat under Drip Irrigation

“…Among them, organic amino acid fertilizers are usually made from pre-treated plant and animal raw materials; they not only provide organic nitrogen and carbon sources to plants but also promote the absorption of nitrogen by crops and improve the fertilizer utilization rate [14,15]. Mineral-source organic humic acid fertilizers are prepared with pre-treated weathered coal, lignite, and peat as raw materials; they not only enhance crop resistance but also promote crop growth and development and improve soil fertility [16,17]. Organic fertilizer leaching solutions are obtained by leaching organic fertilizer or straw and other wastes in solution and are usually rich in organic matter, nitrogen, phosphorus, potassium, and other nutrients, as well as microorganisms, enzymes, hormones, and other biologically active substances.…”