*Corresponding author: Sahjahan Ali, Department of Soil Science, Faculty of Agriculture, Sylhet Agricultural University, Sylhet-3100, Bangladesh, Email: sahjahanali37@gmail.com J. Sylhet Agril. Univ. 4(1):75-78, 2017 ISSN: 2308-1597 EFFECTS OF K, S AND Zn ON GROWTH AND YIELD OF BRRI dhan56 IN ACID SOIL OF SYLHET REGION M M Kamal, M A Kashem, M A Aziz and S Ali* Department of Soil Science, Faculty of Agriculture, Sylhet Agricultural University, Sylhet-3100, Bangladesh (Available online at: www.jsau.com.bd) Abstract An experiment was conducted at the farm of the Bangladesh Agricultural Development Corporation (BADC), Khadimpara, Sylhet 3100 during the period from August to November 2014 to see the effect of K, S and Zn application on the performance of growth, yield and yield contributing characters of BRRI dhan56 under the acidic soil in Sylhet region. The experiment consisted of eight treatments viz, Control, K80, S12, Zn1.8, K80S12, K80Zn1.8, S12Zn1.8 and K80S12Zn1.8. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Data were taken on plant height, number of tillers hill -1 , panicle length, grains panicle -1 , 1000-grain weight, grain and straw yields. Pre and post-harvest soil status was also analyzed to know the status due to K,S and Zn application. Result revealed that all the characters except 1000-grain weight were affected significantly due to application of K, S and Zn. The treatment K80S12Zn1.8 produced the highest plant height (100.40 cm), effective tillers hill -1 (8.13), longest panicle (27.87 cm) and grains panicle -1 (146.60). The highest grain and straw yield of 4.38 and 6.03 t ha -1 , respectively was produced from the treatment K80S12Zn1.8. The lowest performance was observed in the control treatment for all parameters. The soil analyses showed that the nutrient content in post-harvest soils under fertilizer applied soils were slightly higher in comparison to initial soil. Keywords: Acid soil, BRRI dhan56, fertilizer, growth, T. aman season, yield Introduction Bangladesh is a small country with a large population and each year nearly 1.42 million people are being added to its current population of about 162.2 million and growth rate is 1.34% (BBS, 2012). Agriculture is the single largest producing sector of economy since it comprises about 17% of the country’s GDP and employs about 45% of labour forces (BBS, 2015).In Bangladesh rice accounts for 85% annual food grain production and it dominates over all other crops with 77% coverage of the total cropped area (BBS, 2016). The yield of rice is low in Bangladesh in comparison to other rice growing countries. Different chemical fertilizers are used in soil but nutrient stresses are increasing day by day. Major reasons are use of imbalance fertilizers and intensification of crop caused degradation of soil, increase soil acidity, depletion of surface and underground water, pollution of farm and non-farm environment, nutrient mining, arsenic and other heavy metal pollution. Among the improved cultural practices, to ensure proper growth, large amount of chemical fertilizers are applied in different crops field (Shakouri et al., 2012). Judicious and proper use of fertilizers can markedly increase the yield and improve the quality of rice (Alam et al., 2009). So the appropriate fertilizer input that is not only for getting high grain yield but also for attaining maximum profit (Khuang et al., 2008). Unfortunately in our country while considering different aspects of K nutrition to crops emphasis has been laid on inherent supply of K from soil to plant for a long time. On the other hand, there exists a huge gap between annual potassium removal by the crops from the soil and potassium addition through external sources. It would be very optimistic from our part to expect that this deficit of K will be balanced from the native soil. Sulphur (S) is essential macronutrient and it plays a vital role in the plant system. The S deficiency in Bangladesh soil was first detected in rice at BRRI farm at Joydebpur in 1976. In recent years, S deficiency has been receiving much attention as a major limiting factor for wetland rice. Now a days S is commonly included fertilizer for crop production (Islam et al., 2009). Zinc is also one of the most important micronutrient essential for plant growth especially for rice grown under submerged condition. Zinc deficiency is usually corrected by application of zinc sulfate. Zinc deficiency and response of rice to zinc have been reported by many workers (Mollah et al., 2009; Fageria et al., 2011). So, it is needed to identify the suitable combination of chemical fertilizers by maintaining the