无害化污泥施用对土壤有机质、微生物量碳和氮含量的影响

Effects of Non-Hazardous Sewage Sludge Application on Soil Organic Matter and Soil Microbial Biomass Carbon and Nitrogen

合理施用无害化处理后的城市污泥是废弃物资源化利用的重要途径之一。本文采用小麦、玉米轮作的田间连续定位试验,研究了不同施用量的无害化污泥对华北沙化潮土土壤中有机质、微生物量碳和氮含量的影响。结果表明:施用无害化污泥0 t·hm-2(CK)、15 t·hm-2(A1)、30 t·hm-2(A2)和45 t·hm-2(A3)4种处理下,与CK相比,A3处理在小麦季和玉米季土壤有机质含量均得到显著提高(p<0.05),其中小麦季土壤中有机质含量为17.45 g·kg-1,增加了30.91%;玉米季土壤有机质含量为26.52 g·kg-1,增加了80.53%。A2和A3处理对土壤微生物量碳和氮的提升也分别达到显著水平(p<0.05),小麦季A2和A3处理土壤微生物量碳含量分别达到225.91 mg·kg-1和321.18 mg·kg-1,比CK处理分别增加144.20%和247.18%;玉米季A2和A3处理土壤微生物量碳含量分别达到154.41 mg·kg-1和190.75 mg·kg-1,分别增加29.19%和59.60%;小麦季A2和A3处理土壤微生物量氮含量分别达13.53 mg·kg-1和23.92 mg·kg-1,比CK处理分别增加95.52%和245.66%;玉米季A2和A3处理土壤微生物量氮含量分别达29.50 mg·kg-1和30.71 mg·kg-1,比CK处理分别增加40.08%和45.82%。在小麦和玉米轮作周期,随无害化污泥施用量的增加,土壤有机质含量、土壤微生物量碳和氮的含量均得到有效提高;土壤有机质、微生物量碳和氮的含量分别与无害化污泥的不同施用量呈正相关关系。

Applying non-hazardous sewage sludge to land is a good option to utilize wastes. In this study, the effects of different amounts of non-hazardous sewage sludge on soil organic matter（SOM）, soil microbial biomass carbon（SMBC） and nitrogen（SMBN） were investigated in a continuous field experiment with wheat and maize rotation. Four treatments with 3 replicates each, sewage sludge applied at 0 t·hm-2 （CK）, 15 t· hm-2（A 1 ）, 30 t·hm-2（A2） and 45 t· hm-2（A3 ）, were designed. The A3 treatment, significantly increased SOM contents in both wheat and maize season（p〈0.05 ）, compared with the CK treatment. The average SOM was 17.45 g·kg-1 in wheat season and 26.52 g· kg-1 in maize season, 30.91% and 80.53% higher than the CK, respectively. Both SMBC and SMBN contents were also enhanced significantly（p〈 0.05） in the A2 and A3 treatments. In wheat season, SMBC content was 225.91 mg·kg-1 and 321.18 mg·kg-1 in A2 and A3 treatments, respectively, being 144.20% and 247.18% greater than in the CK. In maize season, SMBC contents achieved 154.41 mg·kg-1 and 190.75 mg· kg-1, or increased by 29.19% and 59.60% in A2 and A3 treatment, respectively. Likewise, SMBN contents in the A2 and A3 treatments were 13.53 mg· kg-1 and 23.92 mg· kg-1 in wheat and 29.50 mg· kg-1 and 30.71 mg· kg-1 in maize seasons, or 95.52% and 245.66% and 40.08% and 45.82% increments, respectively. In brief, applications of non-hazardous sewage sludge enhance SOM, SMBC and SMBN, thus improving crop production.