Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics
Dry‐season (DS) grain legume‐weedy fallow‐wet‐season (WS) flooded rice is a common cropping sequence in the rainfed lowlands of tropical Asia. To better manage N in this cropping system, we need to understand N dynamics and balances as influenced by the aerobic‐anaerobic soil aeration sequence, legu...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Language: | Inglés |
| Published: |
Wiley
1995
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/167381 |
| _version_ | 1855537441357692928 |
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| author | George, Thomas Ladha, Jagdish K. Garrity, Dennis P. Torres, Rolando O. |
| author_browse | Garrity, Dennis P. George, Thomas Ladha, Jagdish K. Torres, Rolando O. |
| author_facet | George, Thomas Ladha, Jagdish K. Garrity, Dennis P. Torres, Rolando O. |
| author_sort | George, Thomas |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Dry‐season (DS) grain legume‐weedy fallow‐wet‐season (WS) flooded rice is a common cropping sequence in the rainfed lowlands of tropical Asia. To better manage N in this cropping system, we need to understand N dynamics and balances as influenced by the aerobic‐anaerobic soil aeration sequence, legume cropping, biological N2 fixation (BNF), and recycling of legume residues. To understand N dynamics under a range of N derived from BNF (15N‐estimated), harvested in pods and left in residues, we conducted a 2‐yr experiment on a Philippine Alfisol using cowpea [Vigna unguiculata (L.) Walp.], mungbean [V. radiata (L.) Wilcz.], nodulating and nonnodulating soybean [Glycine max (L.) Merr.], and weeds. The main portion of soil mineral N (0 to 60 cm) was NO3 in the dry season and NH4 in the wet season. The sum of soil NO3 and soil N uptake at legume harvest exceeded the decrease in soil NO3 from legume seeding to harvest by 81 kg ha−1, indicating the continued production and legume uptake of soil NO3. The large differences in total N of legumes (46 to 238 kg N ha−1), however, were associated with differences in N derived from BNF (0 to 176 kg N ha−1). When pod N was excluded, legume N balance was, in most cases, negative. The average soil N depletion was 40 kg ha−1 from nonnodulating soybean, compared with 8 kg ha−1 from N2‐fixing legumes. In terms of WS rice grain and N yields, legume cropping did not differ from weedy fallowing, despite greater (by up to 46 kg N ha−1) quantities of legume residue N in some instances. Large amounts of legume residues, however, were associated with reduced legume grain yields, thus decreasing the harvestable grain N output. Fertilizer N, compared with residue N, had a greater effect on WS rice grain and N yields. The use of legumes in lowland rice‐based cropping systems must maximize harvestable N while effectively using soil, BNF, and applied N sources. |
| format | Journal Article |
| id | CGSpace167381 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 1995 |
| publishDateRange | 1995 |
| publishDateSort | 1995 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | CGSpace1673812024-12-22T05:45:01Z Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics George, Thomas Ladha, Jagdish K. Garrity, Dennis P. Torres, Rolando O. nitrogen nitrogen balance nitrogen fixation cropping systems legumes weeds flooded rice tropics Dry‐season (DS) grain legume‐weedy fallow‐wet‐season (WS) flooded rice is a common cropping sequence in the rainfed lowlands of tropical Asia. To better manage N in this cropping system, we need to understand N dynamics and balances as influenced by the aerobic‐anaerobic soil aeration sequence, legume cropping, biological N2 fixation (BNF), and recycling of legume residues. To understand N dynamics under a range of N derived from BNF (15N‐estimated), harvested in pods and left in residues, we conducted a 2‐yr experiment on a Philippine Alfisol using cowpea [Vigna unguiculata (L.) Walp.], mungbean [V. radiata (L.) Wilcz.], nodulating and nonnodulating soybean [Glycine max (L.) Merr.], and weeds. The main portion of soil mineral N (0 to 60 cm) was NO3 in the dry season and NH4 in the wet season. The sum of soil NO3 and soil N uptake at legume harvest exceeded the decrease in soil NO3 from legume seeding to harvest by 81 kg ha−1, indicating the continued production and legume uptake of soil NO3. The large differences in total N of legumes (46 to 238 kg N ha−1), however, were associated with differences in N derived from BNF (0 to 176 kg N ha−1). When pod N was excluded, legume N balance was, in most cases, negative. The average soil N depletion was 40 kg ha−1 from nonnodulating soybean, compared with 8 kg ha−1 from N2‐fixing legumes. In terms of WS rice grain and N yields, legume cropping did not differ from weedy fallowing, despite greater (by up to 46 kg N ha−1) quantities of legume residue N in some instances. Large amounts of legume residues, however, were associated with reduced legume grain yields, thus decreasing the harvestable grain N output. Fertilizer N, compared with residue N, had a greater effect on WS rice grain and N yields. The use of legumes in lowland rice‐based cropping systems must maximize harvestable N while effectively using soil, BNF, and applied N sources. 1995-01 2024-12-19T12:57:20Z 2024-12-19T12:57:20Z Journal Article https://hdl.handle.net/10568/167381 en Wiley George, Thomas; Ladha, Jagdish K.; Garrity, Dennis P. and Torres, Rolando O. 1995. Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics. Agronomy Journal, Volume 87 no. 1 p. 1-6 |
| spellingShingle | nitrogen nitrogen balance nitrogen fixation cropping systems legumes weeds flooded rice tropics George, Thomas Ladha, Jagdish K. Garrity, Dennis P. Torres, Rolando O. Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title | Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title_full | Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title_fullStr | Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title_full_unstemmed | Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title_short | Nitrogen Dynamics of Grain Legume-Weedy Fallow-Flooded Rice Sequences in the Tropics |
| title_sort | nitrogen dynamics of grain legume weedy fallow flooded rice sequences in the tropics |
| topic | nitrogen nitrogen balance nitrogen fixation cropping systems legumes weeds flooded rice tropics |
| url | https://hdl.handle.net/10568/167381 |
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