No abstract

A field experiment was conducted on sandy soil at El-Ismailia Agric. Res. Station, ARC, during the winter season of 2010/2011 to investigate the influence of different strategies of fertilization, namely compost, biofertilizer and graded levels of mineral N-fertilizer on the vegetative growth, tuber yield and its components of potato plants using drip irrigation system. The used compost was tested for physico-chemical, microbiological characteristics and degree of maturity/stability indices. Obtained results revealed that used compost has acceptable values of main physico-chemical properties such as pH, EC and fertilizer value (macro-and micronutrients). Also, this compost has a valuable biotic strength. In addition, all tested maturity/stability indices indicated that used compost has reasonable degree of maturity and it can applied to cultivated soil without any problem. Data of field experiment showed that growth aspects, potato yield and its components exhibited marked response for compost manuring, N-fertilization or biofertilization, independently and their combination. Soil fertilization with 90, 135 and 180 kg N/fed led to increase potato tuber yield by 17.27, 39.37 and 66.03%, respectively over the lowest level of N (45 kg N/fed). On the other hand, compost manuring the potato plants with 10 and 15 ton/fed resulted in increased tuber yield by 12.23 and 25.02%, respectively over the lowest rate of compost (5 ton/fed). Concerning the nutritional status in shoots and tubers of potato plants, results exerted that increasing the applied level of compost or N-fertilizer resulted in significantly increased concentration of NPK in potato shoot. Moreover, rhizobacterial inoculation led to significant increase protein and potassium concentration in potato tubers. At a given interaction between the fertilization strategies, results clearly exerted that highest values of vegetative growth, tuber yield and nutrient status were attained in case of compost manuring with 15 ton/fed with N-fertilization at rate of 180 kg/fed in presence or absence of rhizobacteria.