IMPACT OF BIOFERTILIZERS AND CHEMICAL FERTILIZERS ON NODULATION, N UPTAKE AND GROWTH OF SOYBEAN (Glycine max L.)

Soybean is one of the important food crops as a source of protein. Nowadays, soybean production should be increased due to higher demand in certain region in Indonesia. Biofertilizer inoculation combine with chemical fertilizer is suggested to increase the soil fertility to support soybean cultivation and decrease the use of chemical fertilizer. The pot experiment was conducted to get the information concerning nodulation, nitrogen uptake and growth of soybeans ( Glycine max L.) after biofertilizer and Nitrogen (N), Phosphorous (P) as well as potassium (K) single fertilizer application. The experiment was set up in a randomized block design with seven treatment and four replications. The treatments consisted of two doses of biofertilizer (3 L ha -1 and 5 L ha -1 ) combined with three doses of N, P, K fertilizer (50%, 75% and 100% recommended dosage). The pot control received no biofertilizer. biofertilizers contained N-fixing bacteria ( Azotobacter chroococcum, A. vinelandii, Azospirillum sp. and endophytic Acinetobacter sp.) and phosphate solubilizing microbes (Pseudomonas cepaceae and Penicillium sp.). The results of experiment showed that the application of biofertilizer 5 L ha -1 combined with 75% chemical fertilizer increased the nodules number, nitrogen uptake and dry weight of plant at the end of vegetative stage. This study suggested that biofertilizer might be used to increase growth of soybean and chemical fertilizer efficiency. The pot experiment was conducted in field station, Faculty of Universitas The experimental site was located in the tropics at 756 m above the sea lavel. The soybean cv Anjasmoro were sown in soil of Inceptisols order collected from Jatinangor District, West Java, Indonesia (clay texture; pH 5,58; C-org 1,89%; N 0,24%; P 2 O 5 Bray 30,25 ppm; CEC 20,76 cmol.kg -1 Consortium biofertilizer which contained N-fixing bacteria Azotobacter chroococcum, A. vinelandii,Azospirillum sp and Acinetobacter sp ., as well as Phosphate solubilizing microbes Pseudomonas cepaceae and Penicillium sp. has been developed by Laboratory of Soil Biology in said Institution. The density of bacteria and fungi in liquid biofertilizers were 10 7 CFU mL -1 and 10 5 CFU mL -1 respectively. Urea, TSP and KCl single Chemical fertilizers were produced by national fertilizer industry. The recommended dosage of said fertilizer for soybean cultivation in Indonesia were Urea (46% N) 50 kg ha -1 , triple super phosphate (36% P 2 O 5 ) 100 kg ha -1 , KCl (60% K 2 O)100 kg ha -1 and cow manure 2 t ha -1 . The compost of cow manure was prepared by Faculty of Husbandry Universitas manure was neutral in acidity 7.50 , N 0.94%, P 2 O 5 0,37% and K 2 O 0.29% and 25.38%