Rice planting decreased total iron but increased active iron.Iron activation varied greatly among different paddy soils but not in woodland soils.Paddy soil iron was mainly affected by pH,SOC and particle composition....Rice planting decreased total iron but increased active iron.Iron activation varied greatly among different paddy soils but not in woodland soils.Paddy soil iron was mainly affected by pH,SOC and particle composition.The decrease of soil Fe was mainly in the form of Fec and was closely related to SOC.展开更多
The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment co...The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment containing four treatments:chemical fertilizer(F),F plus rice straw(FS),FS plus green manure(FSM),FSM with integrated management(FSMM),was performed to examine the effects of incorporation of rice straw and green manure residues on anammox.The results showed that the anammox activities in FS and FSM treatments(0.65 and 0.80 nmol N g^(–1)soil h^(–1),respectively)were significantly lower than those in F and FSMM treatments(1.60 and 1.28 nmol N g^(–1)soil h^(–1),respectively).Anammox contributed 4.07%-4.95%of total N loss in soil incorporated with residues,lower than soil treated with chemical fertilizer only(9.13%),the remaining being due to denitrification.However,the abundance of the hzsB gene(the hydrazine synthaseβ-subunit gene)in FS and FSM treatments(1.13106 and 1.18106 copies g^(–1)soil)were significantly higher than soil using chemical fertilizer only(7.49105 copies g^(–1)soil)while showed no significant difference with FSMM treatment(8.81105 copies g^(–1)soil).Illumina sequencing indicated that Brocadia was the dominant anammox genus,following by Scalindua and Kuenenia.Anammox bacterial diversity was altered after 4-year incorporation of rice straw and green manure,as shown byα-diversity indices.We concluded that rice straw and green manure incorporated with mineral fertilizer reduce N removal from paddy soil in terms of anammox in spite of stimulating anammox bacterial growth.展开更多
基金financially supported by Scientific Research Fund of Hunan Provincial Education Department(Grant No.20A234)San’an Nie thanks the National Natural Science Foundation of China(Grant No.42177288)as well as the National Natural Science Foundation of Hunan Province,China(Grant No.2023JJ30307).
文摘Rice planting decreased total iron but increased active iron.Iron activation varied greatly among different paddy soils but not in woodland soils.Paddy soil iron was mainly affected by pH,SOC and particle composition.The decrease of soil Fe was mainly in the form of Fec and was closely related to SOC.
基金Joint Regional Innovation and Development Fund(UI9A2048)the National Key Research and Development Program of China(2016YFD0300901,2016YFD0300906)+1 种基金the Natural Science Foundation of Hunan Province(2019JJ50338)the National Natural Science Foundation of China(4170010194)。
文摘The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment containing four treatments:chemical fertilizer(F),F plus rice straw(FS),FS plus green manure(FSM),FSM with integrated management(FSMM),was performed to examine the effects of incorporation of rice straw and green manure residues on anammox.The results showed that the anammox activities in FS and FSM treatments(0.65 and 0.80 nmol N g^(–1)soil h^(–1),respectively)were significantly lower than those in F and FSMM treatments(1.60 and 1.28 nmol N g^(–1)soil h^(–1),respectively).Anammox contributed 4.07%-4.95%of total N loss in soil incorporated with residues,lower than soil treated with chemical fertilizer only(9.13%),the remaining being due to denitrification.However,the abundance of the hzsB gene(the hydrazine synthaseβ-subunit gene)in FS and FSM treatments(1.13106 and 1.18106 copies g^(–1)soil)were significantly higher than soil using chemical fertilizer only(7.49105 copies g^(–1)soil)while showed no significant difference with FSMM treatment(8.81105 copies g^(–1)soil).Illumina sequencing indicated that Brocadia was the dominant anammox genus,following by Scalindua and Kuenenia.Anammox bacterial diversity was altered after 4-year incorporation of rice straw and green manure,as shown byα-diversity indices.We concluded that rice straw and green manure incorporated with mineral fertilizer reduce N removal from paddy soil in terms of anammox in spite of stimulating anammox bacterial growth.
