Investigating the growth parameters and yield attributes in different water regimes under the System of Rice Intensification (SRI)

• Main Authors: Zoundou S. Jean Paul, 金保羅
• Other Authors: Wang Yu-Min
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/k496ep

碩士 === 國立屏東科技大學 === 土壤與水工程國際碩士學位學程 === 106 === Abstract The system of rice intensification (SRI) is a friendly-environment rice production system that has been proved to reduce the water consumption and production inputs when at the same time increase yield and water productivity. With the increasing water scarcity due to climate change, water reduction in production is a permanent research issue. The present investigation was carried out to evaluate the effects of different water regimes on the growth parameters and yield attributes of rice under SRI in dry season as well as their related water productivity in irrigated rice, using alternate wetting and drying water management by observation. The study aimed at finding out the optimum irrigated water depth applied to SRI in Taiwan tropical dry season. The experiment was conducted at irrigated rice field in National Pingtung University of Science and Technology (NPUST). SRI management principles such as plant spacing, seedling densities, duration of planting and weeding method have been thoroughly conducted. Five (5) different water depths including the control plots were tested. The control irrigated at 3cm water depth at soil hairline cracks (SRI3) was compared to 2cm (SRI2), 4cm (SRI4) and 5cm (SRI5) water depth under alternate wetting and drying (AWD) irrigation based on visual observations, and also to 3cm water depth per week (SRI3/w), previously identified as optimum water depth. Growth parameters like plant height, leaf area index (LAI), chlorophyll content, and yield attributes such as tillers number, productive tillers number, tillering efficiency, panicles number, panicles length and weight, spikelets number, filled spikelets ratio, 1,000 grains weight, total grain yields and water productivity were assessed. The results showed that the application of 3cm at soil hairline cracks (SRI3) recorded the highest values in most of the growth parameters as well as in the yield attributes. The investigation revealed also that significant differences were observed during some development stages between the different water treatments in the growth parameters assessment as well as in the yield attributes analyses. Yield attributes like spikelets numbers per meter square and filled spikelets percentage were determinant for the grain yield. SRI3 yielded better with 4072kg/ha compared to SRI2 (3448kg/ha), SRI3/w (3340kg/ha), SRI4 (3081kg/ha and SRI5 (2604kg/ha). The highest water productivity was recorded in SRI3 at soil hairline cracks (0.19kg/m 3 ) whereas SRI2 at soil hairline cracks and SRI3/w obtained both 0.18kg/m 3 . Even though they received much water, SRI4 and SRI5 at soil hairline cracks recorded the lowest water productivity with respectively 0.15kg/m 3 and 0.12kg/m 3 of water. The effects of weather conditions on the growing cycle, added to the water stress imposed to rice, resulted in grain yield decline and low water productivity. The findings suggested the application of 3cm water depth after reduced soil hairline cracks as an optimum water treatment for SRI in dry season. Rice cropping period should also be adjusted to avoid the critical temperatures. Key words: System of Rice Intensification (SRI), soil hairlines cracks, growth parameters, yield attributes, optimum water depth.