Effect of sewage sludge and ammonium sulphate fertilization on productivity of olive trees (cv. Chemlali) planted in calcareous soil

摘要

Olive trees (cv. Cbemlali) grown in calcareous soil were supplied with combined rates of sewage sludge (0, 30 and 40 kg/tree) and ammonium sulphate (0, 200, 400, 600 and 800 g N/tree) for two consecutive years. Yield and fruit quality of fertilized trees were studied for three years and compared with that of control. Both yield and fruit quality were generally improved in response to additional fertilizer treatments (sewage sludge and ammonium sulphate). In this respect, rate of 40 kg/tree of sewagesludge proved to be the most effective than the lower rate. Progressive improvement of fruit yield and quality parallel to nitrogen rate applied up to 600 g N/tree were recorded. Results obtained revealed that ammonium sulphate incorporated with sewagesludge produced a synergistic improvements on fruit yield and quality of chemlali olive trees planted in calcareous soil.