Aligning Sowing Dates with the Onset of Rains to Improve Rice Yields and Water Productivity: Modelling Rice (Oryza sativa L.) Yield of the Maha Season in the Dry Zone of Sri Lanka

Simulation of crop and water productivity for rice (Oryza sativa L.) using APSIM under diverse agro-climatic conditions and water management techniques in Sri Lanka

“…Greater runoff and seepage which occurred with onset establishment further reduced the WP at onset establishment. Higher variability in the WP of rice for a late onset season than an early onset season was also reported (Amarasingha et al, 2014). Overall, in years with early rainfall onset; (i) rice crop establishment with the onset assured a reduced quantity of irrigation water requirement, and (ii) early crop establishment under rainfed condition ensured greater yield than a fixed, late date of crop establishment.…”

“…Therefore, sowing rice with the onset of rains may not only increase the efficient use of rainfall, but also reduce irrigation water requirement during the initial or latter phase of the cultivation period thus saving reservoir water (Weerakoon et al, 2005;Amarasingha et al, 2014). This practice may also enhance rice yield while reducing the risk of crop failure, only up to the time when an optimal crop establishment date is reached (Amarasingha et al, 2014). Moreover, unused and saved water from the 'major rainy season(s)' (e.g.…”

“…Cultivation decisions of Sri Lankan farmers are dependent on the onset of rainfall and/or the availability of water in reservoirs/tanks for irrigation (Amarasingha et al, 2014). Hence, timing of crop establishment and the type of variety to be used (i.e.…”

Impact of climate change on rice yield in Sri Lanka: a crop modelling approach using Agriculture Production System Simulator (APSIM)

“…In the literature, APSIM-Oryza has been used to evaluate the impacts of management practices on rice yield and soil resources (Boling et al, 2010;Gaydon et al, 2012a,b;Lijun et al, 2013;Liu et al, 2013a), irrigation management (Feng et al,2007;Malone et al, 2007;Paydar et al, 2009;Soundharajan and Sudheer, 2009;Yadav et al, 2011a,b;Katerji et al, 2013;Liu et al, 2013b;Phung et al, 2013), and fertilizer management (Bouman and van Laar, 2006;Zhang et al, 2007;Micheni et al, 2008). In Sri Lanka, it has been used to evaluate the nitrogen response in lowland rice (Suriyagoda and Peiris, 2013), find optimum planting date for rainfed rice (Rathnayake and Malaviarachchi, 2013) and assess the yield advantage and water productivity when aligning planting date with the onset of rainfall (Amarasingha et al, 2014).…”

“…In a previous study, APSIM-Oryza was parameterized and evaluated for short (Bg300) and medium (Bg359) duration rice varieties grown under standard management conditions in Sri Lanka. The validated model performed well in different agro-climatic zones in Sri Lanka under water-limited farmer-field conditions, predicting the grain yield with a strong model skill (R 2 >0.97, RMSE=484 kg ha -1 ; Amarasingha et al, 2014). Hence, we assumed that the parameterized model is robust enough to be used in testing the performance of rice under possible hypothetical climatic scenarios.…”