基于盆栽试验的施用烟秆生物炭对植烟土壤呼吸速率的影响

摘要

为探索烟秆生物炭对植烟土壤呼吸速率的影响机制,采用盆栽试验在烟草不同生育期测定了土壤呼吸速率、温度和含水率.结果表明,不同施肥措施条件下,植烟土壤呼吸速率随烟草生长发育进程的推进变化明显,烟苗移栽后60 d呼吸速率降至最低,移栽后90 d达到峰值.施用生物炭的土壤呼吸速率均大于不施用生物炭和常规施肥.土壤含水率和温度双因素模型能够更好地表征土壤呼吸速率的变化.各处理土壤呼吸速率温度敏感性系数为2.36~9.41,施用生物炭降低了土壤呼吸速率对土壤温度的敏感程度.常规施肥+12 g/kg生物炭、常规施肥+24 g/kg生物炭、常规施肥-纯氮5%+12 g/kg生物炭、常规施肥-纯氮10%+24 g/kg生物炭处理的土壤呼吸速率与阳离子交换量均呈显著负相关.土壤pH、有机质(除不施肥CK外)、碱解氮、速效磷、速效钾均与土壤呼吸速率呈负相关.因此,添加适量的生物炭可以促进土壤呼吸速率的提高.%To explore the effect of tobacco stalk biochar on soil respiration rate, a pot experiment was conducted to detect the respiration rate, temperature and moisture content of soil at the growth stage of tobacco. The results showed that under different fertilization treatments using the biochar, the respiration rate of tobacco-plant soil changed significantly with the development and growth of tobacco with the lowest and highest respiration rate appeared on the 60th day and the 90th day after tobacco seedling transplanting, respectively. The respiration rate of soil treated with biochar was higher than that without biochar or with conventional fertilization. The variation of soil respiration rate was well characterized by a double-factor model of soil moisture content and temperature. Temperature sensitivity coefficients of soil respiration rate of different treatments were from 2.36 to 9.41. The application of biochar reduced the sensitivity of soil respiration rate to soil temperature. Soil respiration rate of four treatments(conventional fertilization+12 g/kg biochar, conventional fertilization+24 g/kg biochar, conventional fertilization-5% pure nitrogen+12 g/kg biochar and conventional fertilization-10% pure nitrogen+24 g/kg biochar)significantly negatively correlated to cation exchange capacity(CEC). Soil pH, organic matter(except for the control, no fertilization), alkaline hydrolysis nitrogen, available phosphorus and available potassium negatively correlated to soil respiration rate. Therefore, proper biochar could increase soil respiration rate.