生物炭及炭基硝酸铵对土壤微生物量碳、氮及酶活性的影响

Effects of biochar and biochar-based ammonium nitrate fertilizers on soil microbial biomass carbon and nitrogen and enzyme activities

以小麦-玉米轮作交替种植下的田间试验为平台,探讨施用生物炭及3种炭基硝酸铵氮肥对土壤主要化学肥力因子、土壤微生物量碳、氮和酶活性的影响。田间试验共设6个处理,依次为:对照(施磷、钾肥,CK);生物炭(BC);硝酸铵氮肥(AN);掺混型生物炭基氮肥(CH);固-液吸附型生物炭基氮肥(XF);化学反应型生物炭基氮肥(FY)。结果表明,生物炭及3种生物炭基氮肥均显著提高土壤有机碳含量,并有效降低了有效磷和速效钾的含量。与CK处理相比较,CH、BC处理的土壤微生物量碳含量分别增加了22.10%、17.45%,而AN、XF、FY 3个处理则分别减少了9.09%、10.86%、1.46%;不同施肥处理土壤微生物量氮较CK均有增加,且BC、XF处理差异达显著水平,BC处理的增幅最大,达66.53%,XF处理的增幅次之,达到了62.78%,AN处理的增幅最小,为24.86%。与CK处理比较而言,FY、XF、CH均增加土壤蔗糖酶、脲酶和过氧化氢酶活性,且增加效应均依次减弱,FY、XF处理均增加碱性磷酸酶活性,而CH处理降低了碱性磷酸酶活性。FY、XF、CH较CK处理均可显著增加小麦产量,增产率分别为36.61%、22.58%、20.72%,且增产效果依次减弱。

An experiment with a winter wheat-summer maize rotation system was carried out to explore the effects of biochar and biochar-based ammonium nitrate fertilizers on soil chemical fertility, soil microbial biomass carbon and nitrogen, and enzyme activity of soil invertase, urease, catalase, and alkaline phosphatase. Six treatments were used in this study ： control （ CK）, biochar（ BC）, ammonium nitrate control （ AN ） simple mixed type of biochar-based nitrogen （CH）, solid-liquid adsorption type biochar-based nitrogen （XF）, and chemical reaction type biochar-based nitrogen （FY）. The results showed that the content of soil organic carbon significantly increased and the values of available phosphorus and available potassium decreased in biochar and biochar-based nitrogen treatments, CH, XF, FY. Compared to the CK, microbial biomass carbon content increased by 22.10% and 17.45% in CH and BC treatments , respectively, but decreased by 9.09%, 10.86%, 1. 46% in AN, XF and FY treatments, respectively. Microbial biomass nitrogen content was positively affected by all fertilization treatments. In BC and XF treatments, microbial biomass nitrogen significantly （P 〈 0.05） increased by 66.53% and 62.78%, respectively, compared to that in the CK. The increase in the nitrogen content was the lowest in AN treatment and only reached 24.86%, compared to that in the CK. In biochar-based nitrogen treatments, FY, XF, and CH, the enzyme activity of soil invertase, urease and catalase was increased. The effect of FY treatment was the strongest, followed by XF treatment, while the effect of CH treatment was the weakest. Both FY and XF treatments increased the enzyme activity of alkaline phosphatase activity, but its activity decreased in the CH treatment, compared to the CK. Wheat yield in biochar-based nitrogen treatments, FY, XF, CH, significantly increased by 36.61%, 22.58% and 20.72%, respectively, compared to that in the CK. Thus, the biochar-based ammonium nitrate fertilizers, which prepared with biochar and chemical fertilizer can get a good application prospect in agricultural sector.