Field experiment was carried out in Toshka region 300 km south Aswan city during two successive years of 2003 and 2004 to study the efficiency of bio and mineral nitrogen fertilization on growth performance improvement of Acacia saligna and Prosopis juliflora trees cultivated as shelterbelt for sand encroachment control in the area.
Obtained results showed that the growth characters of Acacia saligna and Prosopis juliflora tress were significantly higher in biofertilized and nitrogen fertilization compared to control treatment.
Regarding the nutrients content in leaves, results indicated that the highest values of N, P and K were observed in the treatment of biofertilization combined with nitrogen application at a rate of 150 kg N/fed. Also, obtained results revealed that the biofertilization treatments gave higher values of organic matter content of soil rather than nitrogen fertilization one .Nutrients content of soil (N,P,K.Fe,Cu,Mn and Zn)was significantly higher in the treatment of biofertilization combined with nitrogen application at a rate of 100kg N/fed .
Moreover, biofertilization treatments in presence of nitrogen application (100 kg N/fed) gave lower records of sand accumulation compared with non biofertilization ones.
Shelterbelt efficiency was higher in the treatment of biofertilization combined with nitrogen application at a rate of 100 or 150 kg N /fed being 36.4 and 35.0% for Acacia saligna and Prosopis juliflora, respectively. But, there is no significant difference of shelterbelt efficiency between 100 or 150 kg N/fed
application.
Generally, it can be recommended that the biofertilization process could be applied with Acacia saligna and Prosopis juliflora cultivated as shelterbelt combined with mineral nitrogen application at a rate of 100kg N/fed under similar conditions.