الفهرس 
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Abstract
Intensive application of mineral fertilizers to sandy soils for wheat crop subjected to stresses under semi-arid conditions is affordable to notable losses which cause economic and environmental negative impacts. We hypothesized that wheat growth and productivity could be optimized by combining NPK fertilizers with biochar which can reduce nutrients losses and fulvic acid which enhances plant resistance against environmental stresses. Therefore, pot experiment was conducted during 2017/2018 season using Wheat (Triticum aestivum cv., Misr 1) wherein, wheat seeds were planted in sandy soil collected from the experimental site in El-khattara, Sharkia Governorate, Egypt. Different rates of mineral fertilizers, biochar and fulvic acid were investigated under pot experiment during 2017/2018 season using wheat plants. Before filling the pots, soil was thoroughly mixed with super phosphate (65.4 g kg-1 P) at rates 160, 310, 475 and 635 kg ha-1, potassium sulphate ( 415 g kg-1 K) at rates 143, 190, 240 and 285 kg ha-1 and Ammonium sulphate (205 g kg-1 N) at rates 120, 180, 240, 300 kg ha-1 at four equal doses, after planting by fifteen days and the second, the third and the fourth were added foliar every 21 days. Fulvic acid was sprayed on wheat plants twice, after planting by 30 and 60 days. The results indicated general increment trend in almost investigated parameters except pH and harvest index with increasing fertilizers level especially that combined with biochar at any rate and fulvic acid. The maximum soil N and P contents (63.59 and 38.35 mg kg-1) were reported under the application of maximum fertilizer and biochar level combined with fulvic acid while the lowest value were recorded under the lowest fertilization level without application of biochar or fulvic acid. Unlike, maximum K contents (216.79 and 214.88 mg kg-1) were reported under applying the highest fertilizers level without any amendments or with 30 Mg ha-1 of biochar without fulvic acid. Maximum values of N, P and K content by straw and grain (2.37, 0.59, 2.36, 2.88, 0.97 and 2.31%, respectively) were recorded by applying level 4 combined with 30 Mg ha-1 biochar with fulvic acid whilst, the lowest values (0.91, 0.16, 1.20, 1.49, 0.2 and 1.04 %, respectively) were recorded under the application of lowest fertilization level without biochar or fulvic acid for all parameters. Plant height (cm), grain yield (Mg ha-1) and biological yield (Mg ha-1) recorded maximum values (73.03, 5.13 and 10.00, respectively) under combined application of maximum NPK fertilizer level, 30 Mg ha-1 of biochar and fulvic acid while applying the minimum NPK fertilization level (level 1) without any applications of biochar or fulvic acid resulted in the lowest values (52.56, 2.95 and 4.87, respectively).