ABSTRACT

Generally, application of biochar is an important management practice that can affect soil physico-chemical and biological properties. However, biochar is characterized by high pH and ash content, and due to this, little is known of potential salinization risk of application of biochar to soil. Laboratory incubation experiments were conducted with three replications comprising five treatments according to application rates of biochar (0, 50, 100, 200 and 400 g kg⁻¹ (wt/wt)). The results indicated that application of corn straw biochar to black soil at the rate of 400 g kg⁻¹ resulted in significant increases in soil pH, electrical conductivity (EC) and exchangeable K⁺ and soluble K⁺, Ca²⁺ and Mg²⁺, and decreases in cation exchange capacity (CEC) and exchangeable Ca²⁺ in comparison to untreated soil. Based on stepwise regression analysis, the dominant independent variable that affected soil pH was exchangeable K⁺ saturation percentage. In addition, EC was significantly positively related to potassium adsorption ratio (PAR). It was concluded that increased soil pH and EC are related to biochar (pyrolysis temperature of 600 °C) with higher concentration of K⁺ and lower CEC. This is due to increased exchangeable and soluble K⁺ and decreased soil buffering capacity from high application rate of biochar.

摘要

一般来说，生物炭的施用是一种重要的管理实践，可以影响土壤的理化和生物特性。然而，生物炭的特点是 pH 值和灰分含量高，因此，人们对将生物炭应用于土壤的潜在盐渍化风险知之甚少。根据生物炭的施用率（0、50、100、200和400 g kg ^-1 (wt/wt)），以包括五个处理的三个重复进行实验室孵育实验。结果表明，玉米秸秆生物炭以400 g kg ^{-1 的}比例施用于黑土，显着提高了土壤pH值、电导率（EC）和交换性K ⁺和可溶性K ⁺、Ca ²⁺和Mg²⁺，与未处理的土壤相比，阳离子交换容量 (CEC) 和可交换 Ca ²⁺降低。基于逐步回归分析，影响土壤pH值的主要自变量是可交换钾⁺饱和度百分比。此外，EC与钾吸附率（PAR）呈显着正相关。得出的结论是，土壤 pH 值和 EC 的增加与生物炭（热解温度为 600 °C）有关，K ⁺浓度较高，CEC 较低。这是由于生物炭的高施用率导致可交换性和可溶性 K ⁺增加以及土壤缓冲能力降低。