EFFECT OF METHOD APPLICATION OF HUMIC ACID COMBINED WITH MINERAL N FERTILIZER ON SOIL FERTILITY AND FABA BEAN PRODUCTIVITY IN SANDY SOIL.

     A filed experiment was conducted at winter successive two seasons of  2012/2013 and 2013/2014 in the Farm of Ismalia Agriculture Research Station, (ARC), Ismalia Governorate, Egypt, to study the effect of different methods addition of humic acid on soil fertility and faba bean (Sakha 3) productivity. Theexperiment includes two methods of application (soil application at rates of 5 and 10 kg humic /fed) and foliar application at rates of  (1 g and 2g humic /L water) alone or combined with mineral nitrogen fertilizer at rates of (0, 10, 20 and 30 kg N/fed)  as ammonium nitrate (33.5 %N). The obtained results indicated that the effect of addition humic acid methods (soil application or foliar application) significantly increased growth character i.e. plant height (cm), No. of branch /plant, No. of pods/plant, weight of pods /plant (g) and weight of seed/plant (g) in both seasons. As well as, the methods used of humic acid (soil application or foliar application) at different rates had a significant effect on of seed yield (ton/fed), pods yield (ton/fed) and weight of 100 seeds (g) and chlorophyll, respectively, while the protein content was no significant in both seasons. Concerning the effect of humic acid application on N, P and K concentration in seeds were increased with increasing rates of humic 10 kg /fed and mineral N fertilizer 30 kg N/fed. The interaction between humic acid methods system application and different rates of mineral N were significantly increase for Fe in both seasons but no significant for Mn and Zn concentration in seeds faba bean plants. Also, the soil application of humic acid with 10 kg/fed and foliar application at a rate of 2g humic acid /L with 30 kg N led to highest available N, P and K content in soil after faba bean harvest compared with other treatments. On the other hand, the interaction between methods of humic acid application and different rates of mineral N fertilizer on Fe was significant in the first season and Mn in both seasons, while Zn was no significant in both seasons. It can be concluded that soil application of humic acid at rate 10 kg humic /fed and foliar application at rate 2g/L water had a favorable effect on yield and yield component and improve chemical constituents of faba bean and sandy soil.