氮肥施用下蚯蚓活动对农田氮转化影响的Meta分析

蚯蚓在自然土壤中既能促进植物氮(N)素利用、增加土壤N固持，也会导致土壤N素气逸和淋溶损失，但农田土壤中持续的N肥施用如何影响蚯蚓的这些作用却并不清楚。因此，本研究提取了52篇文献中的202对数据，利用Meta分析从N肥类型、施肥量和施肥方式3个方面进行研究，评估N肥施用下蚯蚓活动对农田N转化的影响。总体结果表明，N肥施用下蚯蚓活动显著增加了作物生物量(地上部、地下部分别增加了12.00%、19.30%)及作物总氮(TN)含量(地上部、地下部分别增加了20.35%、21.06%)，显著增加了土壤可利用N(9.16%)、微生物生物量氮(MBN,23.19%)及脲酶活性(23.73%)，但与此同时也导致土壤氧化亚氮(N₂O)排放和N淋溶增加了16.41%和16.15%。蚯蚓活动对不同肥料类型、施肥量及施肥方式下土壤N转化过程的影响不同。有机-无机N肥配施时，蚯蚓活动对作物生物量和TN含量均有显著的促进作用(地上部、地下部生物量分别增加了17.90%、18.03%；地上部、地下部TN含量分别增加了37.62%、25.76%)；无论N肥施用量为多少，蚯蚓活动均显著增加了作...

Effects of earthworm activity on farmland nitrogen transformation under nitrogen fertilizer application: a Meta-analysis

Earthworms can promote plant N utilization, increase soil N retention, and cause soil N loss through gas escape and leaching in natural soil. However, it is unclear how continuous N fertilizer application affects earthworms on farmland soil. Therefore, 202 data records from 52 pieces of literature were collected and analyzed using a Meta-analysis of N fertilizer type, fertilizer rate, and fertilization method, and the effects of earthworm activity on farmland soil N transformation under N fertilizer application were comprehensively evaluated. The overall results showed that earthworm activity significantly increased crop biomass(aboveground and belowground by 12.00% and 19.30%, respectively), crop total nitrogen(TN) content(aboveground and belowground by 20.35% and 21.06%, respectively), soil available N content(9.16%), microbial biomass N(MBN) content(23.19%), urease activity(23.73%), N₂O emission(16.41%), and N leaching(16.15%). The effects of earthworm activity on soil N transformation differed under different fertilizer types, rates, and methods. Earthworm activity had a significant positive effect on crop biomass(aboveground and belowground biomass increased by 17.90% and 18.03%, respectively) and TN content(aboveground and belowground increased by 37.62% and 25.76%, respectively) when organic-inorganic mixed fertilizer was applied. Earthworm activity significantly increased crop aboveground biomass and aboveground TN content regardless of N fertilizer application rate; however, no such results were found for other parameters. When N fertilizer was applied deeply, earthworm activity significantly increased crop biomass(aboveground and belowground biomass by 16.75% and 22.75%, respectively), TN content(aboveground and belowground by 33.24% and 27.62%, respectively), and microbial activity(MBN and urease by 27.87% and 28.21%, respectively). However, when N fertilizer was applied on the soil surface, earthworm activity only significantly increased available N content(17.56%) and urease activity(9.03%). Furthermore, earthworm activity significantly increased the ecosystem multifunctionality index by 5.93%. Compared with N fertilizer applied on the soil surface, deep application of N fertilizer was more conducive to promoting the positive role of earthworms in farmland soil N transformation. There was no significant difference in the comprehensive effects of N fertilizer types and application rates on the earthworm-induced N transformation.