Effect of various water regimes on rice production in lowland irrigation

• Main Authors: Md. Sarwar, Jahan, Mohd Khairi, Che Lah, Mohd Nozulaidi, Nordin
• Format: Article
• Language: English
• Published: Southern Cross Publishing and Printing Pty Ltd 2015
• Subjects: QD Chemistry
• Online Access: http://eprints.unisza.edu.my/5889/1/FH02-FBIM-15-02670.jpg; http://eprints.unisza.edu.my/5889/
• Institution: Universiti Sultan Zainal Abidin

Water-wise rice production is the current concern. To justify whether less water affects rice production, rice plants were cultivated under different water regimes. Four treatments, T1: flooding at 5 cm depth, T2: flooding at 1 – 3 cm depth, T3: saturated to 1 cm flooding, and T4: alternative wet and dry (AWD), were arranged as completely randomized design with five replicates. Yield and yield parameter, plants physiological, and soil chemical properties were evaluated. Treatment of AWD significantly decreased plant height (9%), tillers number (p ≤ 0.04), panicles number (p ≤ 0.024), filled grains (p ≤ 0.037), yield (p ≤ 0.001) and harvest index (≤ 0.005) but increased unfilled grains (p ≤ 0.011) compared to the control. Chlorophyll (Chl) content (p ≤ 0.003) and Chl fluorescence (p ≤ 0.012), net photosynthesis rate (Pn; p ≤ 0.0001), stomatal conductance (SC; p ≤ 0.0001), transpiration rate (TR; p ≤ 0.0001), and photosynthetically active radiation (PAR; p ≤ 0.001) decreased in plants under T4 treatment than control treatment. Soil pH decreased (p ≤ 0.0001) but soil electric conductivity (EC) increased (p ≤ 0.041) in soil of T4 treatment than that of in soil of control treatments. Nitrogen (N; p ≤ 0.012), phosphorus (P; p ≤ 0.038), potassium (K; p ≤ 0.024) and relative water content (RWC; p ≤ 0.003) decreased under T4 treatment. Treatment T3 saved 45% of water use in T1 treatment and showed higher water use efficiency (WUE) but produced rice yield similar to T1 and T2 treatments. These results suggested that saturated to 1 cm flooding water could easily be implemented in rice cultivation by the farmers which might not affect rice production, plant and soil characters.