caa a22 4500 606219420 CHVBK 20210128101118.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s11104-015-2548-8 doi (NATIONALLICENCE)springer-10.1007/s11104-015-2548-8 Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling [Elektronische Daten] [Xiaoxi Li, Peter Sørensen, Fucui Li, Søren Petersen, Jørgen Olesen] Background and aims: Contributions of legume-based catch crops (LBCCs) to succeeding cereals may be significant. We quantified biological N fixation (BNF) and residual N effects of contrasting CC tops and roots. Methods: BNF of three LBCCs (red clover, winter vetch, perennial ryegrass-red clover mixture) was quantified in microplots by 15N labelling. Their residual effects on spring barley were tested against two non-LBCCs (perennial ryegrass, fodder radish) after spring incorporation of CC tops or roots in monoliths. Results: Total N accumulated in LBCCs was 153-226kg N ha−1, of which 62-66% was derived from BNF in tops and 31-46% in macro-roots (0-18cm soil). Macro-roots represented 31-50% of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50kg N fertilisation ha−1, whereas no extra N uptake was derived from non-LBCCs. The 15N-based N fertiliser values of LBCC tops were 34-47% against 26-29% for non-LBCCs. Conclusions: LBCC roots contributed substantial amounts of N to the system, a source that is usually underestimated. N immobilisation after incorporation of non-LBCCs may hamper the growth of following main crops especially after removing tops. Springer International Publishing Switzerland, 2015 Legume-based catch crop nationallicence Biological N fixation nationallicence Soil N uptake nationallicence Residual N effect nationallicence 15N isotope dilution nationallicence Spring barley nationallicence N : Nitrogen nationallicence DM : Dry matter nationallicence CC : Catch crop nationallicence (Non-)LBCC : (Non-)legume-based catch crop nationallicence BNF : Biological N fixation nationallicence CL : Red clover nationallicence GC : Perennial ryegrass-red clover mixture nationallicence WV : Winter vetch nationallicence FR : Fodder radish nationallicence GR : Perennial ryegrass nationallicence CO : Control without catch crops in large plots nationallicence N0 : Control without residue or fertiliser addition during barley season nationallicence N1 : Control without residue but fertiliser addition during barley season nationallicence EAF : Excess atom fraction 15N nationallicence Ndfa : Percentage of CC-N derived from atmosphere nationallicence Nds : Amount of CC-N derived from soil plus applied 15N-labelled fertiliser nationallicence Ndfr : Barley N derived from CC residues nationallicence NRes_BG : Pool size of 15N-labelled below-ground N in the CC root treatment nationallicence NRes_Top : Amount of N in CC tops incorporated nationallicence ANR : Apparent N recovery nationallicence MFE : Mineral fertiliser equivalent (15N-based) nationallicence NFRV : N fertiliser replacement value (non-15N-based) nationallicence Li Xiaoxi Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut Sørensen Peter Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut Li Fucui College of Natural Resources and Environment, Northwest Agricultural and Forestry University, 712100, Yangling, Shaanxi, China aut Petersen Søren Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut Olesen Jørgen Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 273-287 0032-079X 395:1-2<273 2015 395 11104 https://doi.org/10.1007/s11104-015-2548-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-015-2548-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Li Xiaoxi Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut NATIONALLICENCE 700 1- Sørensen Peter Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut NATIONALLICENCE 700 1- Li Fucui College of Natural Resources and Environment, Northwest Agricultural and Forestry University, 712100, Yangling, Shaanxi, China aut NATIONALLICENCE 700 1- Petersen Søren Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut NATIONALLICENCE 700 1- Olesen Jørgen Department of Agroecology, Aarhus University, Blichers Allé 20, DK 8830, Tjele, Denmark aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 273-287 0032-079X 395:1-2<273 2015 395 11104