Natural abundance of 15N in tropical plants with emphasis on tree legumes |
| |
Authors: | T Yoneyama T Muraoka T Murakami N Boonkerd |
| |
Institution: | (1) Department of Soils and Fertilizers, National Agriculture Research Center, 305 Tsukuba, Ibaraki, Japan;(2) Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba, SP, Brasil;(3) Soil Science Division, Department of Agriculture, Bangkhen, 10900 Bangkok, Thailand |
| |
Abstract: | Natural abundance of 15N ( 15N) of leaves harvested from tropical plants in Brazil and Thailand was analyzed. The 15N values of non-N2-fixing trees in Brazil were +4.5±1.9, which is lower than those of soil nitrogen (+8.0±2.2). In contrast, mimosa and kudzu had very low 15N values (–1.4+0.5). The 15N values of Panicum maximum and leguminous trees, except Leucaena leucocephala, were similar to those of non-N2-fixing trees, suggesting that the contribution of fixed N in these plants is negligible. The 15N values of non-N2-fixing trees in Thailand were +4.9±2.0. Leucaena leucocephala, Sesbania grandiflora, Casuarina spp. and Cycas spp. had low 15N values, close to the value of atmospheric N2 (0), pointing to a major contribution of N2 fixation in these plants. Cassia spp. and Tamarindus indica had high 15N values, which confirms that these species are non-nodulating legumes. The 15N values of Acacia spp. and Gliricidia sepium and other potentially nodulating tree legumes were, on average, slightly lower than those of non-N2-fixing trees, indicating a small contribution of N2 fixation in these legumes. |
| |
Keywords: | natural 15N abundance N2 fixation Panicum maximum tree legumes tropical ecosystem |
本文献已被 SpringerLink 等数据库收录! |
|