Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania
Organic amendments can reportedly sustain and increase lowland rice productivity in smallholder systems. Few studies have assessed locally-available substrates in hydrologically variable floodplain environments. We investigated the effects of green and farmyard manures on rice yields, and total soil...
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MDPI AG
2020-08-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/10/9/1280 |
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| author | Julius Kwesiga Kristina Grotelüschen Kalimuthu Senthilkumar Daniel Neuhoff Thomas F. Döring Mathias Becker |
| author_facet | Julius Kwesiga Kristina Grotelüschen Kalimuthu Senthilkumar Daniel Neuhoff Thomas F. Döring Mathias Becker |
| author_sort | Julius Kwesiga |
| collection | DOAJ |
| description | Organic amendments can reportedly sustain and increase lowland rice productivity in smallholder systems. Few studies have assessed locally-available substrates in hydrologically variable floodplain environments. We investigated the effects of green and farmyard manures on rice yields, and total soil C and N in the Kilombero floodplain, Tanzania. At both the fringe and the middle positions, five treatments were applied in 2016 and 2017, comprising (1) non-amended control, (2) farmyard manure, (3) pre-rice legumes, (4) post-rice legumes and (5) a combination of green and farmyard manures. Residual treatment effects were assessed in 2018 when rice plots were uniformly non-amended. Depending on the year and the position, organic amendments increased rice grain yields by 0.7–3.1 Mg ha<sup>–1</sup> above the non-amended control. Sole green and farmyard manure applications had similar effects on grain yield, while a combination of green and farmyard manure led to a significant increase in grain yield above both the control and sole applications of organic amendments in both years. The contribution from biological N<sub>2</sub> fixation by legumes ranged from 4 to 61 kg N ha<sup>–1</sup>. Despite partial N balances being mostly negative, we observed positive residual effects on the yield of the non-amended rice in the third year. Such effects reached up to 4 Mg ha<sup>−1</sup> and were largest with post-rice legumes, sole or combined with farmyard manure. Irrespective of the position in the floodplain, manures significantly increased soil C and N contents after two years, hence enhancing soil fertility and resulting in increased rice grain yields. Comparable benefits may be obtained along the hydrological gradients of other large river floodplains of the region and beyond. |
| first_indexed | 2024-03-10T16:43:56Z |
| format | Article |
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| issn | 2073-4395 |
| language | English |
| last_indexed | 2024-03-10T16:43:56Z |
| publishDate | 2020-08-01 |
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| series | Agronomy |
| spelling | doaj.art-8132972d049142488e91858298754d392023-11-20T11:49:29ZengMDPI AGAgronomy2073-43952020-08-01109128010.3390/agronomy10091280Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of TanzaniaJulius Kwesiga0Kristina Grotelüschen1Kalimuthu Senthilkumar2Daniel Neuhoff3Thomas F. Döring4Mathias Becker5Institute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, GermanyInstitute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, GermanyAfrica Rice Center (AfricaRice), P.O. Box 1690, Antananarivo 101, MadagascarInstitute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, GermanyInstitute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, GermanyInstitute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, GermanyOrganic amendments can reportedly sustain and increase lowland rice productivity in smallholder systems. Few studies have assessed locally-available substrates in hydrologically variable floodplain environments. We investigated the effects of green and farmyard manures on rice yields, and total soil C and N in the Kilombero floodplain, Tanzania. At both the fringe and the middle positions, five treatments were applied in 2016 and 2017, comprising (1) non-amended control, (2) farmyard manure, (3) pre-rice legumes, (4) post-rice legumes and (5) a combination of green and farmyard manures. Residual treatment effects were assessed in 2018 when rice plots were uniformly non-amended. Depending on the year and the position, organic amendments increased rice grain yields by 0.7–3.1 Mg ha<sup>–1</sup> above the non-amended control. Sole green and farmyard manure applications had similar effects on grain yield, while a combination of green and farmyard manure led to a significant increase in grain yield above both the control and sole applications of organic amendments in both years. The contribution from biological N<sub>2</sub> fixation by legumes ranged from 4 to 61 kg N ha<sup>–1</sup>. Despite partial N balances being mostly negative, we observed positive residual effects on the yield of the non-amended rice in the third year. Such effects reached up to 4 Mg ha<sup>−1</sup> and were largest with post-rice legumes, sole or combined with farmyard manure. Irrespective of the position in the floodplain, manures significantly increased soil C and N contents after two years, hence enhancing soil fertility and resulting in increased rice grain yields. Comparable benefits may be obtained along the hydrological gradients of other large river floodplains of the region and beyond.https://www.mdpi.com/2073-4395/10/9/1280<i>Lablab purpureus</i>N<sub>2</sub>-fixationδ<sup>15</sup>N natural abundance<i>Oryza sativa</i><i>Stylosanthes guianensis</i><i>Vigna unguiculata</i> |
| spellingShingle | Julius Kwesiga Kristina Grotelüschen Kalimuthu Senthilkumar Daniel Neuhoff Thomas F. Döring Mathias Becker Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania Agronomy <i>Lablab purpureus</i> N<sub>2</sub>-fixation δ<sup>15</sup>N natural abundance <i>Oryza sativa</i> <i>Stylosanthes guianensis</i> <i>Vigna unguiculata</i> |
| title | Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania |
| title_full | Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania |
| title_fullStr | Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania |
| title_full_unstemmed | Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania |
| title_short | Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania |
| title_sort | effect of organic amendments on the productivity of rainfed lowland rice in the kilombero floodplain of tanzania |
| topic | <i>Lablab purpureus</i> N<sub>2</sub>-fixation δ<sup>15</sup>N natural abundance <i>Oryza sativa</i> <i>Stylosanthes guianensis</i> <i>Vigna unguiculata</i> |
| url | https://www.mdpi.com/2073-4395/10/9/1280 |
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