生物质炭对砖红壤性质与养分及硝化作用的影响

Effects of Biochar Application on Soil Physical Properties,Nutrients and Nitrification in Latosol

土壤性质制约着作为氮转化重要环节的硝化作用,生物质炭显著影响与硝化作用密切相关的土壤性质,可能对硝化作用产生影响。本文利用培养试验研究生物质炭对砖红壤性质及硝化作用的影响。试验设生物质炭+淹水、生物质炭+75%田间持水量、空白+淹水及空白+75%田间持水量4个处理。研究表明,生物质炭能显著提高土壤pH值和有机碳含量以及N、P、K养分元素的有效性。水分条件差异影响生物质炭的作用效果,淹水更利于提高砖红壤的pH值,但显著降低了磷的有效性。添加生物质炭后,土壤硝化作用进程加速,硝化彻底。在利用生物质炭改良砖红壤时,应根据土壤改良目的调整土壤水分,以防硝态氮淋失风险和氨挥发的可能。

Nitrification process, an important link of N transformation, is restricted by the soil properties. Biochar can significantly change the soil characteristics which are closely related to the nitrification, so application of biochar to soil will influence the nitrification process. Incubation experiments were arranged to study the effects of biochar applicaiton on soil properties and nitrification process in latosol. The incubation experiment involved with 4 treatments of two levels of soil water content （75% of field capacity and waterlogging） and two levels of biochar （application and zero）. The results showed that the biochar significantly increased soil pH, organic carbon content and the available content of N, P and K. The effects of soil moisture could change the influence of biochar on soil characteristics. Flooding was more conducive to increase value of pH, but significantly reduce.d the content of available P. Addition of biocar to soil accelerated the nitrification rate and most NH4^＋ was nitrified to NO3^-. Soil moisture should be adjusted to the soil improvement goals to prevent nitrate leaching risk and the possibility of ammonia volatilization, when biochar was used for modifying latosol.