Int.J.Curr.Microbiol.App.Sci (2017) 6(11): 570-576 570 Original Research Article https://doi.org/10.20546/ijcmas.2017.611.069 Growth and Yield of Soybean as Influenced by Different Ratios and Levels of Nitrogen and Phosphorus under Rainfed Situations Satyabrata Mangaraj 1* , L.H. Malligawad 2 and R.K. Paikaray 1 1 College of Agriculture, OUAT, Bhubaneswar, Odisha, India 2 College of Agriculture, UAS, Dharwad, Karnataka, India *Corresponding author ABSTRACT Introduction Soybean (Glycine max L. Merrill), a species of grain legume called as the “GOLDEN BEAN” of the 20 th century is widely grown for its edible bean having numerous uses. Soybean is considered as a wonder crop due to its dual qualities viz., high protein (40- 43%) and oil content (20%). In addition, soybean protein has 5% lysine which is deficient in most cereals. In India, area under soybean crop is about 10.33 M ha with annual production of 8.91 Mt with an average productivity of 983 kg ha -1 (Anon., 2015) which is much less than world average despite it is introduced in India during 1880. In Karnataka, soybean crop is cultivated in an area of 0.2 lakh ha with an annual production of 0.22 Mt and productivity of 1103 kg ha -1 . Among the factors responsible for low productivity, inadequate fertilizer use and emergence of multiple-nutrient deficiencies due to poor recycling of organic sources and unbalanced use of fertilizers are the most important. The crop is often subjected to both water logging and soil moisture deficit in the growing season. Many a times even with normal distribution of rainfall, crop suffers from excess soil moisture during peak International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 11 (2017) pp. 570-576 Journal homepage: http://www.ijcmas.com A field experiment was carried out during kharif 2015 with thirteen ratios of nitrogen (N) and phosphorus (P 2 O 5 ) fertilizers with constant potassium level (25 kg K 2 O ha -1 ) on soybean cultivar DSb 21 at MARS, UAS, Dharwad. The seed yield increased due to increasing N/P ratios up to 0.78. The treatment receiving N/P fertilizer ratio of 0.70 (basal application of 18 kg N, 46 kg P 2 O 5 , 25 kg K 2 O ha -1 + foliar application of nitrogen @ 7 kg N ha -1 at initiation of flowering and foliar application of nitrogen @ 7 kg N ha -1 at 15 days after first foliar spray) recorded significantly higher seed yield (3217 kg ha -1 ), number of filled pods plant -1 (44.73), total number of pods plant -1 (47.57), 100 seed weight (15.40 g) and seed weight plant -1 (18.31 g). This treatment also recorded significantly higher leaf area plant -1 (12.62 dm 2 ), leaf area index (4.21) and total dry matter production (34.15 g). The treatment receiving N/P fertilizer ratio of 0.78 (basal application of 40 kg N, 69 kg P 2 O 5 , 25 kg K 2 O ha -1 + foliar application of nitrogen @ 7 kg N ha -1 through urea at initiation of flowering and foliar application of nitrogen @ 7 kg N ha -1 at 15 days after first spray) was on par with the N/P fertilizer ratio of 0.70. Keywords Rainfed, Foliar application, Seed yield, Fertilizer ratio. Accepted: 07 September 2017 Available Online: 10 November 2017 Article Info