RESPONSE OF SOYBEAN GROWTH TO NANO-MINERAL FERTILIZERS UNDER TWO IRRIGATION INTERVALS

During summer seasons of 2015 and 2017, a field experiment was conducted at the Research and Experimental Station (30°19′ N, 31°16′ E), Faculty of Agriculture, Ain Shams University at Shalakan, Kalubia Governorate, Egypt, to investi-gate the effects of combinations between hydroxyl apatite nanoparticles (0, 3, and 6 kg/fad) and cal-cium carbonate nanoparticles (0, 500g/fad) as nano-fertilizers under irrigaton intervals, (irrigation every 2 or 3 weeks whereas irrigation every 2 weeks as a recommended practice) on growth of soybean plants. Irrigation intervals had statistically significant effect on plant height (cm), number of branches per plant, number of leaves per plant, leaf area index, number of pods per plant, number of root nodules per plant, root dry weight per plant, stem dry weight per plant, leaves dry weight per plant and pods dry weight per plant. These results were fairly true in the two studied seasons 2015, 2017 and combined result. plant height, numbers of branches per plant, numbers of leaves per plant, leaf area index, number of nodules per plant and number of pods per plant of soybean plants which treated with 500 g/fed surpassed untreated plants in the two studied seasons 2015, 2017 and com-bined. Soybean plants treated with 6 kg hydroxyl apatite nanoparticles per feddan out-numbered other plants in its numbers of leaves per plant, leaf area index, number of root nodules per plant and number of pods per plant in the two growing sea-sons 2015, 2017 and combined data. Results showed that normal irrigation x 500g/fed calcium carbonate nanoparticles x 6kg/fed hydroxyl apatite nanoparticles was the effective combination for producing the highest values of plant height (cm), number of branches per plant, number of leaves per plant, leaf area index, number of pods per plant, number of root nodules per plant, root dry weight per plant (g), stem dry weight per plant (g), leaves dry weight per plant (g) and pods dry weight per plant (g). There weren’t significant results be-tween plants treated with nano-mineral fertilizers under irrigation every 3 week and plants untreated but irrigated every 2 week in all growth traits, which reflect appositive result of this chemical substance in mitigation harmful effect of water shortage in season 2015, 2017 and combined data.