Abstract :
Tow field trials were carried out in 2010 and 2011 summer seasons to study the effect of mineral, organic, natural rocks and biofertilizers on yield and yield components of Sahka 53 and Giza 102 sunflower varieties in newly reclaimed soils. The field experiments were layout at the Agricultural Experimental Desert station, Faculty of Agriculture, Cairo University at Wadi El-Natroon, El-Beheira Governorate, Egypt. The results showed that the applying of organic fertilizers, natural mineral rocks and biofertilizers had positive effect on yield and yield components of two sunflower varieties under sandy soil condition as compared to NPK mineral fertilizers. Fertilizing with various rates of compost, natural mineral rocks and biofertilizers increased head diameter, seed yield /plant, seed yield /faddan and 100-seed weight by 4%, 5%,13% and 5% as compared to plants received recommend NPK mineral fertilizer dose,respectively at the first season and the corresponding values at the second one were 4%,8%,19% and 3% in the same order. The obtained results showed that, there were no significant effect of the interaction between the varieties and various form of fertilization (organic, bio and mineral) application in most of the studied traits except in seed oil content and seed protein content in both seasons. On the other hand, applying of compost, bio fertilizers and natural mineral rocks had support Rhizosphere microorganism (RMO) and gave higher values of total bacteria counts, nitrogenase and dehydrogenase activity as compared to untreated treatments.
