Effect of Urea and Potassium Sulfate Fertilizers Combined with Boron on Soil Fertility and Sugar Beet Productivity in Salt Affected Soil

 
 
        A FIELD experiment was conducted an saline sodic soil at El-Quntra  …….Shark, Ismailia governorate, Egypt, during two successive winter seasons of 2012/2013 and 2013/ 2014. It amid to evaluate the effect of urea and potassium sulfate fertilizers at different rates alone or combined with boron on some soil properties and its content of available nutrients and sugar beet productivity as well as the roots content of macronutrients and yield quality in salt affected soil. The soil has a sandy loam texture and is saline sodic (EC_e = 12.18 dS/m, SAR= 22.78 and pH = 8.13). The experimental design was randomized complete block with three replicates. Urea and potassium sulfate fertilizers at three different rates, were arranged in the main treatment and applied in three equal doses after 30, 50 and 75 days from planting. The boron rates at 0.0 and 0.5 kg boric acid fed^-1 in three doses at the same periods of N, K application then randomly distributed in sub treatments.
 
Results showed that increasing N+K₂O fertilizers rates up to 150 kg N and 100 kg K₂O.fed^-1 combined with B significantly decreased soil salinity, and significantly increased the available N and K, while P was not significantly affected. Sugar beet yield and yield quality as well as the nutrients content in root of sugar beet increased with increasing the rates of N+K₂O combined with B. The maximum sugar beet yield of root (15.96 ton/fed), sugar yield (2.26 ton/fed), sucrose (16.07 %) and protein percentage (13.13%) were achieved with 150 kg N + 100 kg K₂O / fed combined with 0.5 kg B. fed^-1. Also, application of N+K₂Orates had a significant positive effect on root fresh weight/plant, root diameter, and juice purity percentage in both seasons.  Raising the N+K₂O fertilizers rates combined with B significantly augmented the content of N, P and K in roots during the two growing seasons. The observation which ought to be mentioned herein that, the combination of 150 kg N + 100 kg K₂O.fed^-1 with B at rate of 0.5 kg B. fed^-1 as foliar spray could be recommend to obtain economical yield with satisfactory quality and to improve the soil fertility under the conditions of the studied area.