USING NATURAL ALTERNATIVE FERTILIZERS FOR POTATO PRODUCTION UNDER SANDY SOIL CONDITIONS IN EGYPT

Abstract

Two field experiments were carried out during the two successive seasons of 2010/2011 and 2011/2012 in the Farm of Agric. Res. Station, Wady El-Natrown Area, Fac. Agric. Cairo University, Egypt under saline water and sandy soil conditions. This investigation aimed to study the effect of compost, natural alternative fertilizers (rock phosphate and feldspar) combined with bacterial inoculation (Azotobacter spp and Azospirillum perna + B. megaterium + B. circulans) on yield, tubers quality and its component of (dry matter, NPK, carbohydrate and nitrate) of potato tubers Diamant cultivar. Azotobacter spp and Azospirillum perna were used as nitrogen fixing bacteria from compost, B. megaterium was used as phosphate dissolving bacteria from rock phosphate and B. circulans was used as potassium dissolving bacteria from feldspar. The experiment included 13 treatments as follows three compost levels source of (N) (5.9, 8.8, 11.8 ton/fed.), three rock phosphate levels source of (P) (204.4, 140.7, 77.04 kg/fed.) and five feldspar levels source of (K) (888.8, 592.6, 580.7, 333.3, 251.9 kg/fed.) compared with control (mineral NPK at rate of 120 N -75 P2O5 - 96 K2O kg/fed.) were applied in a (RCBD) randomized complete blocks design with three replicates. Results at harvest showed that significant increases in yield characteristics as (yield/plant, total yield, number of tubers and weight of tubers/plant) and tubers quality (dry matter, carbohydrate, nitrate) were treated with high rate of compost (11.8 ton/fed.) combined with potassium at the highest rate in the presence of bacterial inoculation mixture and showed significantly increasing compared with control. Therefore, compost, rock phosphate, feldspar and biofertilizers could be an alternative to mineral fertilizer for potato production.