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Carbon and Nitrogen Release from Legume Crop Residues for Three Subsequent Crops
Author(s) -
Lupwayi Newton Z.,
Soon Yoong K.
Publication year - 2015
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2015.05.0198
Subject(s) - vicia faba , sativum , lathyrus , legume , crop residue , green manure , forage , agronomy , field pea , pisum , crop , vicia villosa , residue (chemistry) , fabaceae , biology , chemistry , horticulture , botany , cover crop , agriculture , ecology , biochemistry
Pulse crops are grown on the Canadian prairies because of their agronomic, economic, and environmental benefits. They are recommended to be grown once every 4 yr, but N release from their residues is usually quantified over one crop season following their harvest. We estimated biologically fixed N and monitored patterns of C and N release from residues of green and forage pea ( Pisum sativum L.), faba bean ( Vicia faba L.), faba green manure (GM), and chickling vetch ( Lathyrus sativus L.) GM in three subsequent crop years. Pulses fixed more N, particularly faba bean (184 kg N ha −1 ) and forage pea (165 kg N ha −1 ), than GM legumes (77 and 95 kg N ha −1 ), and they contained more C (1839–2577 kg C ha −1 ) than GM residues (1072 and 1240 kg C ha −1 ). Vetch GM, faba bean, and forage pea residues contained the most N (129–153 kg N ha −1 ), and green pea the least (65 kg N ha −1 ). Green manure residues released > 80% of their C and N contents, and pea residues released 46 and 62% of their C and about 50% of their N in the first year, but pea residues released more C and N than GM residues in the second and third years. Faba bean residues released 70% and 63% of their C and N, respectively, in the first year. After 3 yr, 3–5% of GM residue organic C and N remained in the soil, compared with 9–18% and 13–16% of pulse crop C and N, respectively. Therefore, pulse and GM residues had different patterns of C and N release.