Soil organic matter content and chemical composition under two rotation management systems in a Mediterranean climate  

作　　者：Carlo ANGELETTI Elga MONACI Beatrice GIANNETTA Serena POLVERIGIANI Costantino VISCHETTI 

机构地区：[1]Department of Clinical Sciences(DISCO),Section of Biochemistry,Polytechnic University of Marche,Via Ranieri 67,Ancona 60131(Italy) [2]Department of Agricultural,Food and Environmental Sciences(D3A),Polytechnic University of Marche,Via Brecce Bianche 10,Ancona 60131(Italy)

出　　处：《Pedosphere》2021年第6期903-911,共9页土壤圈（英文版）

基　　金：funded by the Department of Agricultural,Food and Environmental Sciences(D3 A),Polytechnic University of Marche,Ancona,Italy。

摘　　要：The crop rotation system in organic farming is a determinant factor to accumulate and preserve soil organic matter(SOM),and in depth knowledge on its effects is still lacking.Tillage intensity in particular is crucial to maintain soil aggregates and protect SOM from degradation.The evolution of SOM was tested in two adjacent fields under two different rotation cropping systems(low-intensity tillage and high-intensity tillage),and the effect of a further cultivation of legume in both fields was evaluated using ^(13)carbon(C)-nuclear magnetic resonance(NMR)and elemental analysis of samples isolated through combined aggregate size and density fractionation.The two adjacent fields had been managed using the following organic farming methods for 13 seasons since 1998:i)alfalfa-based,with nitrogen(N)enrichment and low-frequency tillage with alfalfa(Medicago sativa)(9 seasons),winter wheat(Triticum durum)(3 seasons),and broad bean(Vicia faba)(1 season)and ii)cereal-based,with N depletion and annual tillage with barley(Hordeum vulgare)(7 seasons),sunflower(Helianthus annuus)(2 seasons),broad bean(Vicia faba)(3 seasons),and bare fallow(1 season).Soil sampling was carried out at the end of the 13-year rotation(T0,November 2011)and after winter wheat and chickpea cultivation in both fields over two subsequent years(T1,July 2013).Bulk organic C was significantly higher in the alfalfa-based system than in the cereal-based system at both T0 and T1,with SOM occluded in soil aggregates and associated with mineral particles.In terms of the macroaggregates heavy fraction at T0,the alfalfa-based field contained twice the organic C of that in the cereal-based field,as well as three times the organic C in the occluded particulate organic matter(POM).The occluded POM(oPOM)had a lower aryl/O-alkyl C ratio in the alfalfa-based system than in the cereal-based system,suggesting that oPOM undergoes a lower degree of decomposition during low-intensity management.The aryl/O-alkyl C ratios of the macro-and microaggregate oPOM decreased from T

关 键 词：crop rotation organic carbon ^(13)C-NMR soil organic matter accumulation particulate organic matter organo-mineral association 

分 类 号：S153.621[农业科学—土壤学]