INFLUENCE OF SOME BIO-, ORGANIC AND MINERAL FERTILIZERS ON MORPHOLOGICAL, PRODUCTIVE AND CHEMICAL CHARACTERS OF SOYBEAN [Glycine max (L.) Merr.] PLANTS

Abstract

ABSTRACT The present investigation was carried out at the Agricultural Experimental Station, Faculty of Agriculture, Cairo University, Giza, Egypt during the two growing seasons of 2019 and 2020. This work was designed to investigate the effect of Bradyrhizobium japonicum as biofertilizer, algae extract, organic fertilizer (compost) and mineral nitrogen fertilizer (ammonium sulphate 20.5%N) as different sources of nitrogen fertilization treatments, on morphology, seed yield components and chemical constituents of soybean [Glycine max (L.) Merr.] plants grown under sandy soil condition. Seeds were sown on May 12th of the two seasons in plastic pots (30 cm diameter). Each pot received calcium super phosphate (15.5% P2O5) and potassium sulphate (48% K2O) as a basal dressing factor. The present study included single or combined treatments of the adopted fertilizers as well as untreated plants (with no added N source). The obtained results showed that biofertilizer Bradyrhizobium japonicum was efficient for increasing most of the studied morphological characters, seed yield components and chemical constituents of soybean plants than those of untreated ones. Application of either algae extract or compost or mineral nitrogen as a single treatment or combined with biofertilizer (half dose of each fertilizer + biofertilizer ) mostly had considerable effects on the studied characters than those of bio-inoculum as a single treatment. The combined treatment of bio-inoculum with half dose of any fertilizer caused positive effects on morphology, productivity and chemical constituents of soybean plant than those of each fertilizer used as a single treatment (full dose). The combination of ½ mineral nitrogen + bio-inoculum was the reliable treatment than the others for increasing most of the studied morphological traits as main stem length, number of secondary branches/plant, number of leaves /plant, leaf area/plant, shoot fresh weight/plant, shoot dry weight /plant, also yield components as number of pods/plant, number of seeds/plant, seed yield /plant. The highest increase induced in stem diameter achieved with the treatment of ½ mineral nitrogen + bio-inoculum due to the prominent increases in thickness of all included tissues as well as increasing diameter of pith. Also, the same treatment caused more positive effects on the studied anatomical traits of leaflet blade. The combination treatment between mineral nitrogen fertilizer as half dose and Bradyrhizobium japonicum was reliable treatment for increasing values of chlorophyll a, chlorophyll b and carotenoids in the fresh leaves as well as increasing percentages of N, P, K, total carbohydrates, oil and protein in air dried seeds. Key words: Soybean, Bradyrhizobium japonicum, Algae extract, Compost, Nitrogen.