Khafagy, E. E. E.( 2014). Effect of nitrogen fertilization and some foliar applied micronutrients on potato yield and nitrogen use efficiency.J. Soil Sci. and Agric. Eng., Mansoura Univ., Vol. 5 (8): 1125 - 1139, 2014
Abstract: Two field experiments were carried out at Batra village, Talkha district, in Dakahlia Governorate, Egypt, during the winter growing seasons of 2012/2013 and 2013/2014. The experimental design was split plot with three replications. The aim of this research was to evaluate the effect of nitrogen fertilization level, foliar spraying of mixed (Fe, Zn & Mn) and their interactions on potato crop, quality; NPK uptake and N use efficiency. The main plots were assigned for nitrogen levels (0, 150, 175, 200 and 225 kg N fed.-1), but the sub plots were devoid for foliar mixed Fe, Zn and Mn sulfates at the ratio 2:1:1 (at the rate: 0, 1.25 & 2.5 g L-1). Application of N-levels significantly increased average weight of tuber, total tuber yield and shoot dry yield while foliar application of Fe, Zn and Mn mixture treatments induced significant increases in both tuber and shoot yield only. The interaction effect of N level and macronutrients on the above mentioned parameters was not significant except the average weight of tuber which showed significant effect in the first season only and application of 200 kg N fed.-1 combined with T3 recorded the heaviest tubers (219.0 and 229.2g) for the first and the second seasons, respectively. Dry matter, protein and starch % in tubers were significantly affected by N levels and foliar applied icronutrients, while the interaction showed no significant effect. The uptake of N, P and K was significantly increased with increasing N-levels and micronutrient concentration while the interaction effect was not significant. The values of N utilization efficiency and N uptake efficiency were decreased with increasing of N-levels. whereas N-level of 200 kg N fed.-1 recorded the highest percentage of N apparent recovery fraction in both seasons. The interactions between N-levels and foliar Fe, Zn and Mn treatments affected N utilization efficiency, N uptake efficiency and N apparent recovery fraction% and the highest percentage of N apparent recovery fraction were 37.13 and 40.55 % in 1st and 2nd season, respectively with the interaction of N level (175 and 200 kg N fed.-1, respectively) and foliar Fe, Zn and Mn treatment at 1.25g L-1.
Keywords: (iron, zinc, manganese, nitrogen, potato, yield, NPK, uptake, efficiency.)
