Investigation on the fertilization characteristics of apple orchard in Yimeng mountainous area

The fertilization characteristics and the nutrient profit and loss in apple orchards of Yimeng Mountain area were investigated from 2009 to 2010 to provide the scientific basis for the nutrient input.The results showed that:high quality organic fertilizer was used in 87.1% orchards;compound fertilizer was used in all orchards;and compound fertilizer with high content of nitrogen,phosphorus and potassium was used in 7.1% orchards.Both organic and chemical fertilizers were excessively used,especially the chemical fertilizer.The nitrogen,phosphorus and potassium in organic fertilizer accounted for 101.1%,143.4% and 67.6% of theoretical requirement respectively,and in chemical fertilizer for 160.3%,184.8% and 132.0% respectively.The orchards with nutrient surplus for nitrogen,phosphorus and potassium accounted for 96.2%,100.0% and 84.9% of the total survey orchards respectively,and 0.067 hm2 mean surplus of nitrogen,phosphorus and potassium were 73.9 kg,57.6 kg and 45.1 kg respectively.The result of pH analysis indicated that the slightly acidic and neutral soil of some orchards had been acidized significantly.It was suggested that grass-growing and mulching could be used as a major approach to increase the organic matter in the soil;that soil regime,tree vigour and the performance of nitrogen,phosphorus and potassium in the soil should be considered before fertilization;and that the nutrient content of organic fertilizer should be taken into account when the nutrient input was calculated.Meanwhile,the reference fertilizing scheme for apple orchards in Yimeng Mountain area and fertilizing principle for retarding soil acidizing progress were proposed.