Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 1678-1684 1678 Original Research Article https://doi.org/10.20546/ijcmas.2021.1002.198 Phosphatase Activity and Phosphorus Use Efficiency of Cowpea as Influenced by Genotypes, Phosphorus Levels and Liquid based PSB M.S.R. Kalyani and Ganajaxi Math* Department of Agronomy, College of Agriculture, UAS, Dharwad-580005, Karnataka, India *Corresponding author ABSTRACT Introduction Legumes are a vital component in Indian cropping systems owing to their ability to provide significant quantities of proteins to the vegetarian diet. Cowpea (Vigna unguiculata (L.) Walp) is a multipurpose grain legume grown commercially for its long green pods, seeds and fodder in arid and humid tropics. It is called ‘‘Vegetable meat’’ due to its high protein content with better biological value, bears green tender pods containing protein (4.3 g), carbohydrate (8.0 g), fats (0.6 g) and fiber (2 g) per 100g of edible portion. Amino acids particularly leucine, lysine and phenylalanine contents are comparatively high in cowpea. Tender fruits contain calcium (80 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 10 Number 02 (2021) Journal homepage: http://www.ijcmas.com A field experiment was conducted to evaluate the phosphatase activity and phosphorus use efficiency of cowpea genotypes to phosphorus levels and liquid based PSB during kharif 2019 under rainfed condition at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad. Among the genotypes, the genotype DC-15 recorded significantly higher phosphatase activity, agronomic and recovery efficiency ( 45.22 μg paranitrophenol g -1 soil hr -1 , 8.53 and 0.040 kg kg -1 , respectively) than the genotype GC- 3. It was on par with the genotype KBC-9. Among the phosphorus levels, the application of 75 kg P 2 O 5 ha -1 + liquid PSB @ 4ml kg -1 seeds recorded significantly higher phosphatase activity (53.96 μg paranitrophenol g -1 soil hr -1 ) over other phosphorus levels. Whereas, higher recovery efficiency (0.041 kg kg -1 ) was recorded with the application of 25 kg P 2 O 5 ha -1 + liquid PSB @ 4ml kg -1 over significantly higher over other phosphorus levels. Among the interactions, DC-15 with the application of 75 kg P 2 O 5 ha -1 + liquid PSB @ 4ml kg -1 seeds recorded significantly higher phosphatase activity (59.67 μg paranitrophenol g -1 soil hr -1 ) over the control and other treatments. However, the genotype DC-15 with the application of 25 kg P 2 O 5 ha -1 + liquid PSB @ 4ml kg -1 seeds recorded significantly higher recovery efficiency (0.057 kg kg -1 ) over the control and other treatments. Keywords Cowpea genotypes, Phosphorus levels, Liquid based PSB, Seed yield Accepted: 15 January 2021 Available Online: 10 February 2021 Article Info