氮肥施用下蚯蚓活动对农田氮转化影响的Meta分析

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

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(N_(2)O)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物地上部生物量和地上部TN含量,但对其他指标无显著影响;N肥深施时,蚯蚓活动显著增加了作物生物量(地上部、地下部生物量分别增加了16.75%、22.75%)、TN含量(地上部、地下部TN含量分别增加了33.24%、27.62%)和微生物活性(MBN、脲酶分别增加了27.87%、28.21%),而N肥表施时,蚯蚓活动仅显著增加了土壤可利用N含量(17.56%)和脲酶活性(9.03%)。蚯蚓活动显著增加生态系统多功能性(5.93%)。N肥深施相比N肥表施更有助于充分发挥蚯蚓在农田土壤N转化过程中的积极作用,而N肥类型和施用量对蚯蚓诱导的N转化过程的综合作用并无显著影响。

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%),N_(2)O 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 organicinorganic 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.