Effect of Nutrient Application on Growth, Metabolic and Enzymatic Activities of Rice Seedlings During Flooding Stress and Subsequent Re‐Aeration

Abstract

The impact of submergence on the allometry, changes in metabolic activities and antioxidant enzymes during oxidative stress in four Indica rice varieties namely IR-20, IR-64 Sub1, Swarna Sub1 and Savitri Sub1 was studied. The differential response of flooding under clear and turbid water with different nutrient application schedules was also examined during and after 12 days of complete submergence. Submergence substantially reduced allometric parameters and the activities of antioxidant enzymes but increased the % change in chlorophyll, soluble sugars and malondialdehyde (MDA) across cultivars with drastic effects on IR-20. Turbid water resulted in higher leaf senescence, lodging, higher depletion of chlorophyll and soluble sugars because of poor light transmission. Pre-submergence N application resulted in higher lodging, leaf senescence and higher MDA level but depletion of chlorophyll and NSC leading to higher % change over prior to submergence. Basal P application reduced the senescence and lodging, whereas increased the antioxidant enzyme activities. Foliar spray of postsubmergence N with basal P improved the retention and regain of chlorophyll, soluble sugar and increased the dry matter, leaf area and root shoot ratio. Crop establishment could therefore be enhanced in areas where untimely flooding is anticipated by applying basal P and foliar spray of urea after desubmergence.

Effect of simulated flash flooding on rice and its recovery after flooding with nutrient management strategies

“…However, semi-dwarf rice cultivars having submergence tolerance developed in the recent years have been found to respond to N application and thus withstand excess water stress better (Reddy et al, 1986). Basal fertilization of nitrogen (Reddy et al, 1985) and nitrogen and phosphorus (Gautam et al, 2014b;Lal et al, 2014) improves initial vigor of rice plants for better tolerance to submergence at later growth stages. Post-submergence nutrient application can also contribute substantially towards increasing productivity in flood-prone areas (Gautam et al, 2014a;Lal et al, 2014).…”

“…Basal fertilization of nitrogen (Reddy et al, 1985) and nitrogen and phosphorus (Gautam et al, 2014b;Lal et al, 2014) improves initial vigor of rice plants for better tolerance to submergence at later growth stages. Post-submergence nutrient application can also contribute substantially towards increasing productivity in flood-prone areas (Gautam et al, 2014a;Lal et al, 2014). In this context, the study is conducted with submergence tolerant rice varieties for harnessing the productivity potentials and minimizing flood damages in rice production through alteration in method of post-flood N application with basal P.…”

Combined application of silica and nitrogen alleviates the damage of flooding stress in rice

“…In deep-water floods, most of rice varieties show the capacity of elongation of leaves and some part of stem (internode) that is entrapped under water. This elongated, tall plant easily lodges when the floodwater moves away, and underwater elongation could cause death of the plant within a few days by exhausting energy reserves of the plant (Lal et al 2014).…”

“…It is also suggested to play a crucial role in preventing or minimising lodging in cereal crops (Munir et al 2003), providing culm sturdiness and increased leaf erectness, a matter of great importance in terms of agricultural productivity. Basal fertilisation of N (Reddy et al 1985), and of N + P (Gautam et al 2014a;Lal et al 2014), improves initial vigour of rice plants for better tolerance to submergence at later growth stages. Post-submergence N application can also contribute substantially to increasing productivity in flood-prone areas (Gautam et al 2014b;Lal et al 2014).…”

“…Basal fertilisation of N (Reddy et al 1985), and of N + P (Gautam et al 2014a;Lal et al 2014), improves initial vigour of rice plants for better tolerance to submergence at later growth stages. Post-submergence N application can also contribute substantially to increasing productivity in flood-prone areas (Gautam et al 2014b;Lal et al 2014). However, the role of Si in the growth and survival of rice under submergence is unknown and information on the combined effect of Si, N and P on completely submerged rice is negligible.…”