International Journal of Plant & Soil Science

Two field experiments were conducted at the village of Khaled Ibn El-waleed, Sahl El-Hossinia Agricultural Research Station, El-Sharkia Governorate, Egypt, during the two summer seasons 2019 and 2020 to estimate the effect of NPK nano-fertilizers, bio-fertilizers and humic acid (in addition to different doses of mineral fertilizers) on soil chemical properties and productivity of soybean in saline soil. The treatments were NPK-chitosan, NPK-Ca, humic acid, biofertilzer and control (mineral NPK only). In the two seasons, the experiment design was a split plot in three replicates.

The results indicated a slight decrease in soil pH, while there was a significant decrease in EC values in all the studied treatments as compared to control. Also, the soil available macronutrients (nitrogen, phosphorous and potassium) and micronutrients (iron, manganese and zinc) were significantly increased after application of the studied treatments as compared to control. Also, there was a significant increase in the content of macro and micronutrients in soybean grains as affected by the studied treatments. This may be attributed to that addition of the used amendments like nano chitosan, humic acid and biofertilizers companied by decomposition of organic materials released acids that reduced soil pH which caused nutrients to be more soluble hence more available for plant uptake. The results indicated also a significant increase in the soybean yield parameters as plant height, weight of seeds and weight of pods in all treatments as compared to control. There was also a significant increase in the soybean content of protein, oil and chlorophyll in all of the investigated treatments as compared to control.