Study On The Mineral Nutrient Ratio Of Improving The Size Of Chongming Narcissus Bulbs

This paper focused on the key situation that low soil fertility on Chongming island and unscientific fertilization ratio that used by local farmers which lead to serious degradation of Chongming Narcissus. Using "3414" field fertilization experiment, field survey sampling, with laboratory analyzing and the regression equation to study on the impaction of nitrogen, phosphorus and potassium fertilizer on the growth of narcissus bulbs in order to provide the basis for improving cultivation techniques for Chongming Narcissus.The results are as follows:The study on the impaction by individual element showed that with the amount of fertilizer increasing, Narcissus circumference increased significantly. The best increasing caused by nitrogen fertilizer, the maximum circumference increased by 59.3%, followed by potash, the maximum increased by 36.0%, phosphorus only 30.7%. Combined application of nitrogen, phosphorus and potassium fertilizer can promote each other, in a certain range of fertilizer. In the range of 0-76.75kg/hm2, increasing the amount of nitrogenous fertilizer application can improve the nitrogen content of the Narcissus bulbs. When the amount of phosphate reached 61.5kg/hm2, the phosphorus content of Narcissus bulbs improved significantly. The same to potassium fertilizer, when reached to 43.75kg/hm2, the growth rate of potassium of Narcissus bulbs was the highest.For the first time this paper used the fertilizer equation to calculate the accurate dosage of nitrogen, phosphorus and potassium. Theoretically calculated by equation application of nitrogen fertilizer 320.06kg/hm2, phosphorus 172.62kg/hm2, potassium 228.73kg/hm2, the Narcissus bulb circumference can increase the maximum 47.76mm. According to the equation and the price of the fertilizers, the recommended dosage is:nitrogen fertilization 81.13 kg/hm2,46.63 kg/hm2 phosphate, potassium 38.81 kg/hm.