不同生物炭对安徽宣城旱地红壤氮矿化的影响

Effects of Various Biochars on Soil Nitrogen Mineralization in Red Soil of Upland

采用连续间隙淋洗培养法,研究了竹炭、烟草秸秆炭及棉花秸秆炭对安徽宣城旱地红壤氮素矿化作用的影响。结果表明:3种生物炭均可提高土壤p H,但p H增长幅度与生物炭用量相关,最高可增加2个单位;不同用量的生物炭添加都会导致土壤氮素硝化速率及矿化速率的降低,竹炭、烟草秸秆炭及棉花秸秆炭分别使硝化速率最大降幅达49.2%、72.3%与69.2%,矿化速率最大降幅达33.7%、61.9%与61.1%。因此,生物炭实际施用需作谨慎的评估,优化其使用方法。

The method of Standford and Smith was employed to study the effects of bamboo, tobacco and cotton biochars on soil nitrogen mineralization in a red soil of upland. The results showed that the three biochars increased soil pH value which was related to their application rates. The highest increase of pH was 2 units when biochar added. Various biochars in different application rates could result in the decline of soil nitrification and mineralization rates. The maximum decrease of nitrification rate was 49.2%, 72.3% and 69.2% by bamboo, tobacco and cotton biochars, respectively, and the greatest decrease of mineraliza- tion rate was 33.7%, 61.9% and 61.1%, respectively. Therefore, it is important to evaluate carefully the application of biochars and an optimization of use should be considered in practice.