Long-term effects of urea and green manure on rice yields and nitrogen balance
Data from a 14‐yr double‐crop rice (Oryza sativa L.) experiment allowed comparison of the long‐term effects of N fertilizer from different sources (urea and in situ grown azolla [Azolla microphylla Kaulf.] and sesbania [Sesbania rostrata Bremek. and Oberm.]) on N balances, soil N pools (both total a...
| Main Authors: | , , , , , |
|---|---|
| Format: | Journal Article |
| Language: | Inglés |
| Published: |
Wiley
2000
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/167073 |
| _version_ | 1855537481044197376 |
|---|---|
| author | Ladha, J.K. Dawe, D. Ventura, T.S. Singh, U. Ventura, W. Watanabe, I. |
| author_browse | Dawe, D. Ladha, J.K. Singh, U. Ventura, T.S. Ventura, W. Watanabe, I. |
| author_facet | Ladha, J.K. Dawe, D. Ventura, T.S. Singh, U. Ventura, W. Watanabe, I. |
| author_sort | Ladha, J.K. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Data from a 14‐yr double‐crop rice (Oryza sativa L.) experiment allowed comparison of the long‐term effects of N fertilizer from different sources (urea and in situ grown azolla [Azolla microphylla Kaulf.] and sesbania [Sesbania rostrata Bremek. and Oberm.]) on N balances, soil N pools (both total and available), and yields. Although data show that plant‐available N was maintained over time in both wet (WS) and dry seasons (DS), yields declined significantly, indicating a decline in physiological N use efficiency. The yield declines were generally similar regardless of N source in both seasons. The WS decline averaged 150 kg ha−1 yr−1 in the three added‐N treatments, while the DS decline averaged 185 kg ha−1 yr−1. After 27 crops, the cumulative positive N balance was estimated at 1244, 348, 646, and 1039 kg N ha−1 in control, urea, sesbania, and azolla treatments, respectively. There was no significant change in soil total N content in the control and urea treatments, whereas it increased to 344 to 541 kg after 27 crops in the sesbania and azolla treatments. Conservation of the soil N status and positive N balance, in spite of the high amounts of N removed through grain and straw, reflect the N contribution (13–46 kg ha−1 crop−1) from nonsymbiotic N2 fixation. In addition, sesbania and azolla were estimated to add ≈57 to 64 kg ha−1 crop−1 through symbiotic N2 fixation. These results demonstrate that in rice–rice cropping systems biological N fixation plays a vital role in replenishing the soil N pool. However, continuous application of green manure N (GM‐N) did not increase crop N availability, perhaps because of the presence of a recalcitrant soil organic matter fraction. Residual effects on rice grain yield and N uptake were observed only with GM‐N sources. |
| format | Journal Article |
| id | CGSpace167073 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2000 |
| publishDateRange | 2000 |
| publishDateSort | 2000 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | CGSpace1670732025-12-08T09:54:28Z Long-term effects of urea and green manure on rice yields and nitrogen balance Ladha, J.K. Dawe, D. Ventura, T.S. Singh, U. Ventura, W. Watanabe, I. nitrogen fertilizers nitrogen balance urea green manures yields Data from a 14‐yr double‐crop rice (Oryza sativa L.) experiment allowed comparison of the long‐term effects of N fertilizer from different sources (urea and in situ grown azolla [Azolla microphylla Kaulf.] and sesbania [Sesbania rostrata Bremek. and Oberm.]) on N balances, soil N pools (both total and available), and yields. Although data show that plant‐available N was maintained over time in both wet (WS) and dry seasons (DS), yields declined significantly, indicating a decline in physiological N use efficiency. The yield declines were generally similar regardless of N source in both seasons. The WS decline averaged 150 kg ha−1 yr−1 in the three added‐N treatments, while the DS decline averaged 185 kg ha−1 yr−1. After 27 crops, the cumulative positive N balance was estimated at 1244, 348, 646, and 1039 kg N ha−1 in control, urea, sesbania, and azolla treatments, respectively. There was no significant change in soil total N content in the control and urea treatments, whereas it increased to 344 to 541 kg after 27 crops in the sesbania and azolla treatments. Conservation of the soil N status and positive N balance, in spite of the high amounts of N removed through grain and straw, reflect the N contribution (13–46 kg ha−1 crop−1) from nonsymbiotic N2 fixation. In addition, sesbania and azolla were estimated to add ≈57 to 64 kg ha−1 crop−1 through symbiotic N2 fixation. These results demonstrate that in rice–rice cropping systems biological N fixation plays a vital role in replenishing the soil N pool. However, continuous application of green manure N (GM‐N) did not increase crop N availability, perhaps because of the presence of a recalcitrant soil organic matter fraction. Residual effects on rice grain yield and N uptake were observed only with GM‐N sources. 2000-11 2024-12-19T12:56:58Z 2024-12-19T12:56:58Z Journal Article https://hdl.handle.net/10568/167073 en Open Access Wiley Ladha, J.K.; Dawe, D.; Ventura, T.S.; Singh, U.; Ventura, W. and Watanabe, I. 2000. Long-term effects of urea and green manure on rice yields and nitrogen balance. Soil Science Soc of Amer J, Volume 64 no. 6 p. 1993-2001 |
| spellingShingle | nitrogen fertilizers nitrogen balance urea green manures yields Ladha, J.K. Dawe, D. Ventura, T.S. Singh, U. Ventura, W. Watanabe, I. Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title | Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title_full | Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title_fullStr | Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title_full_unstemmed | Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title_short | Long-term effects of urea and green manure on rice yields and nitrogen balance |
| title_sort | long term effects of urea and green manure on rice yields and nitrogen balance |
| topic | nitrogen fertilizers nitrogen balance urea green manures yields |
| url | https://hdl.handle.net/10568/167073 |
| work_keys_str_mv | AT ladhajk longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance AT dawed longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance AT venturats longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance AT singhu longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance AT venturaw longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance AT watanabei longtermeffectsofureaandgreenmanureonriceyieldsandnitrogenbalance |