Department of Botany, Jagannath University, Dhaka-1100, Bangladesh
Soil Science Division, Bangladesh Rice Research Institute, Gazipur-1701, Bangladesh
Nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) are the most important plant nutrients in terms of the extent of their deficiencies in the soils, and their potential for crop yield increases or losses. Present experiment was conducted in wet season of 2014 at the Bangladesh Rice Research Institute (BRRI) farm, Gazipur in a permanent layout first designed in dry season of 1985. Objectives of the research were to (i) study the effects of NPKS on growth and yield of wet season rice (ii) determine the yield limiting nutrient (s) in BRRI farm soil and NPKS doses for wet season rice (iii) examine the relationship between grain yield and some agronomic parameters of wet season rice. A popular modern rice variety BRRI dhan49 was tested with five fertilizer treatments: NPKS (complete), PKS (-N), NKS (-P), NPS (-K) and NPK (-S). The NPKS were applied @ 100-7-80-3 kg/ha. Considerable reduced plant height, tiller/m2, panicle/m2, grain and straw yield of BRRI dhan49 was recorded due to omission of N, K, P and S nutrients from the complete treatments. The highest yield reduction was recorded due to N omission and was found the most limiting nutrient in BRRI farm soil followed by K, P and S. Phosphorus omission delayed the flower initiation by 5 days and extended the life cycle of wet season rice by 4 days. Estimated doses of major plant nutrients for BRRI dhan49 rice cultivation were 116, 19, 54 and 3 kg/ha N, P, K and S, respectively.