Role of Belowground Parts of Green Manure Legumes, Crotalaria spectabilis and Sesbania rostrata, in N Uptake by the Succeeding Tendergreen Mustard Plant
Autor: | Bongsu Choi, Masamichi Ohe, Jiro Harada, Hiroyuki Daimon |
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Jazyk: | angličtina |
Rok vydání: | 2008 |
Předmět: | |
Zdroj: | Plant Production Science, Vol 11, Iss 1, Pp 116-123 (2008) |
Druh dokumentu: | article |
ISSN: | 1343-943X 1349-1008 |
DOI: | 10.1626/pps.11.116 |
Popis: | Using symbiotically N2-fixing legumes as green manures is a way to supply N from the atmosphere to cropping ecosystems. Usually whole plants of the green manure are incorporated into soil; hence, the belowground parts as well as the aboveground parts would contribute to N transfer to succeeding crops. However, little is known about the contribution of the belowground parts alone. We assessed N transfer from belowground parts compared to whole plants of two legumes, Crotalaria spectabilis and Sesbania rostrata. Each of the legumes was grown approximately for 3 months in a 1/2000a Wagner pot filled with soil media, and then the roots alone (R) or shoot and root (S + R) were harvested and incorporated in the pots. Tendergreen mustard (Brassica rapa) as the succeeding crop was grown for 66 days in these pots without additional fertilizer. Although the amount of N in green manure in S + R pots was approximately 4-fold higher than that in R pots, differences in N uptake by tendergreen mustard between the S + R and R pots were smaller (1.7-fold for C. spectabilis and 2.3-fold for S. rostrata). This means that N recovery rate by tendergreen mustard was significantly higher in R than in S + R pots with either green manures. Differences in C/N ratio of the green manures could not likely explain the higher N recovery rate in R pots. Bioassay of the aqueous extracts from the green manure with lettuce seedlings suggested that growth inhibitory effects might be responsible for the lower recovery rate in S + R treatment. |
Databáze: | Directory of Open Access Journals |
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