INFLUENCE OF SOME POTASSIUM HUMATE APPLICATION METHODS AND MINERAL FERTILIZATION OF NITROGEN AND PHOSPHORUS ON SOYBEAN YIELD AND QUALITY

Abstract

Two field experiments were conducted on Gadila village, Mansoura city, Dakahlia Governorate during the two successive summer seasons of 2017 and 2018 as sake of studying the impact of some methods of potassium humate (KH) application along with nine mixtures of NP fertilizers on soybean plants . split plot design was used where KH application methods and NP mixtures were put in the main and sub plots, respectively. Addition of KH generally had enhancing impacts on soybean growth , seed and stalk yields as well as improved seed nutritive and biochemical contents. Foliar spraying of KH achieved the maximum values followed by seed coating and control in a descending order. Soil application of (100 % N + 100 % P) mixture attained the best results for all aforementioned characteristics with no significant difference between it and (75 % N + 100 % P) mixture. Foliar spraying of soybean plants with 2% KH solution (10% K2O) in a volume of 200 L fed -1 at 30 and 45 days after sowing and soil application of (75 % N + 100 % P) of the recommended doses, in a dual treatment achieved the superior impacts and recorded the highest values of plant growth criteria, productivity as well as improved seed quality characteristics and saved 25 % of N requirement for soybean plants.