硝化抑制剂和秸秆对潮棕壤碳氮转化和微生物群落特征的短期影响

氮是植物和微生物生长繁殖的必需营养元素,而氮矿化表征了土壤供氮能力。通过盆栽实验,采用同位素稀释法和磷脂脂肪酸(PLFA)法,研究了添加硝化抑制剂和秸秆条件下,潮棕壤碳氮矿化和微生物群落组成变化特征。结果表明,与施氮量N 0.1 g·kg~(-1)的单施氮肥处理(NF)相比,氮肥配施1%硝化抑制剂(NFI)的土壤铵态氮提高32%,而硝态氮降低53%。氮肥与施用量为5 g·kg~(-1)的秸秆配施(NS),土壤氮素总矿化速率增加36%,微生物生物量碳提高51%,β-葡萄糖苷酶活性提高36%,同时显著增加了土壤总PLFA以及细菌、真菌、真菌/细菌和革兰式阴性菌(P0.05),土壤呼吸熵降低50%。与氮肥配施秸秆处理(NS)相比,氮肥、秸秆和硝化抑制剂配施处理(NSI),土壤铵态氮提高33%,硝态氮下降47%。综上所述,氮肥和秸秆配施可以提高土壤微生物生物量,改变土壤微生物群落组成,配施1%(N)硝化抑制剂后降低土壤硝化速率,增加土壤供氮能力。

Short term effects of nitrification inhibitor and straw on aquic brown soil carbon and nitrogen mineralization and microbial community structure

Nitrogen is essential nutrient element for the activity and growth of soil microorganisms and plants.Nitrogen mineralization is an important index for the soil supplying capability.Effects of supplying nitrification inhibitor and straw on mineralization of aquic brown soil carbon and nitrogen and soil microbial community structure characteristics were studied using the isotope dilution approach and phospholipid fatty acid method under wheat pot experiment.The results showed that compared with nitrogen fertilizer alone treatment (NF) (N 0.1 g · kg-1 soil),in nitrogen fertilizer with 1％ nitrogen inhibitor (NFI) treatment soil ammonium contents was increased by 32％,and the nitrate was reduced 53％.Compared with NF,in the nitrogen fertilizer with straw (NS) treatment (5 g · kg-1),the soil gross nitrogen mineralization rate,microbial biomass carbon,β-glucosidase activity were increased by 36％,51％ and 36％,respectively,the total PLFA,bacteria,fungi,fungi/bacteria and gram negative bacteria increased significantly,soil respiration entropy decreased by 50％.In the nitrogen,straw and nitrification inhibitor treatment,soil ammonium contents was increased by 33％,the nitrate was reduced 47％.In conclusion,nitrogen fertilizer with straw improved soil microbial biomass and soil microbial community.Application of 1％ nitrification inhibitor decreased the soil nitrification rates,improved soil nitrogen efficiency,and reduced the risk of N lose.