(1) pumpkin root system fertilizer absorption characteristics: pumpkin root system is well-developed, the main root into the soil can be about 2 meters deep, more than 20 first-class lateral roots, about 50 cm long, the longest up to 140 cm, and can be divided into three or four levels of lateral roots, forming a strong root group, the main root group densely distributed in the 10 ~ 40 cm tillage layer. Because the pumpkin roots into the soil deep, wide distribution, so the ability to absorb fertilizer is also very strong, has a strong drought resistance and infertile resistance. The soil requirements are not strict, even if planted in the more infertile plots can also grow. Cultivation of pumpkin in the sticky and fertile soil, often due to the stem and leaves of the appendage and caused by the fall of flowers and fruits, but the yield is not high. Therefore, early cultivation should be selected for deep, well-drained, fast warming sandy loam; late cultivation of varieties should be selected for water and fertility of loamy soil planting, suitable soil pH 6.5 ~ 7.5. In the soil fertility is sufficient, should be reasonably dense planting, timely branching, picking, can make full use of fertility to obtain high yields.
(2) pumpkin fertilizer dynamics: pumpkin different stages of growth and development of nutrient uptake and absorption ratio varies. Seedlings require less fertilizer, into the fruit expansion period is the period of maximum fertilizer requirements, especially the absorption of nitrogen increased sharply, potassium also has a similar trend, phosphorus absorption increased less. According to Miyazaki, Japan, the pumpkin from planting to the 137 days of seedling pulling, the first 1/3 of the time to the five elements (nitrogen, phosphorus, potassium, calcium, magnesium) absorption increased slowly, the middle 1/3 of the time to grow rapidly, and the last 1/3 of the time to grow most significantly. The uptake of the five elements was highest for potassium and nitrogen, intermediate for calcium, and lowest for magnesium and phosphorus during the whole period. The increase in yield was in complete agreement with the general trend of five-factor uptake, which also increased rapidly in the last 1/3 of the time. The production of 1000 kg of pumpkin requires the uptake of nitrogen (N) 3.5-5.5 kg, phosphorus (P2O5) 1.5-2.2 kg and potassium (K2O) 5.3-7.29 kg. Pumpkin responds well to organic fertilizers such as stable manure and compost.
(3) pumpkin in the early growth of too much nitrogen fertilizer, easy to cause stem and leaf growth, the head of the melon easy to fall off; too late application of nitrogen fertilizer will affect the fruit expansion
