Effects of drainage intensity on water and nitrogen use efficiency and rice grain yield in a semi-arid marshland in Rwanda |
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| Authors: | Olive Tuyishime Abraham Joel Ingmar Messing Francois Naramabuye Muthiah Sankaranarayanan |
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| Institution: | 1. University of Rwanda, College of Agriculture, Animal Sciences and Veterinary Medicine, Musanze, Rwanda;2. Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden;3. Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden  https://orcid.org/0000-0003-0184-9455;4. Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden https://orcid.org/0000-0002-8548-0933;5. University of Rwanda, College of Agriculture, Animal Sciences and Veterinary Medicine, Musanze, Rwanda;6. University of Rwanda, College of Agriculture, Animal Sciences and Veterinary Medicine, Nyagatare, Rwanda |
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| Abstract: | ABSTRACT Drainage management is important in intensification of irrigated paddy rice production. This study assessed the effects of drainage intensity on water and nitrogen use efficiency and rice grain yield in a field experiment conducted during three seasons in Rwanda. The experiment comprised 12 plots with four blocks and three treatments: DS0.6 (0.6 m deep drain), DD11.2 (1.2 m deep drain, control structure open four times per week), and DD21.2 (1.2 m deep drain, control structure open two times per week). Outflow was calculated from water balance. Nitrogen (N) content in drainage water was determined weekly. Crop yield and N uptake were determined in grain and straw. In all seasons, grain yield was 61–131% higher, crop N uptake was 24–90% higher, harvest index (HI) was 24–65% higher and water use efficiency (WUE) was 50–150% higher in treatments DD11.2 and DD21.2 than in DS0.6. There was a decrease in soil carbon/nitrogen ratio at the end of Seasons 2 and 3. Recirculating straw to fields is thus necessary to replenish SOC for long-term soil fertility. A practical implication of the study is that managed deep drainage systems could enhance water use efficiency and rice grain yield in poorly drained paddy fields. |
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| Keywords: | Surface drainage paddy rice nutrient losses rice yield harvest index |
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![ORCID Icon]({"type":"image","src":"/templates/jsp/images/orcid.png"} "ORCID Icon")
https://orcid.org/0000-0003-0184-9455;4. Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden