The Study Of Plug Seedling Substrate And Coupling Effect Of Water And Fertilizer On Onion

Onion (Allium cepa L.) is one of the most vegetable since it possesses a unique flavor and odor that makes it an excellent food source in the world. In recent years, the consumption of onion has increased rapidly, therefore, onion is of broad of prospects. But the current seedling method and the extensive cultivation have lead to the wastes of each kind of resources and caused serious consequences of vegetable's export development. So the paper was carried out to select the localization plug seedling and to study the coupling effect of fertilizer and water on onion and the theories basis for offering the practice technology for the factory of onion seedlings and establishing security, high quality are provided. The results were as follow:1 Under the condition of this experiment, soil,ashes, organic fertilizer were used to form the suitable plug seedling for onion. The optimum combination was treatment A. The ratio was thatsoil: ashes: pig manure: corn straw was 2:1:1:1. The properties of treatment A during the seedling period is that bulk density 0.74⁰..77g/cm³, water retaining capacity 40⁵0%, aeration porosity 14. 93¹5.42, EC 0.7⁰.9ms/cm pH 6.16⁶.37. The seedling index and growth rate of seedling were 0.209g and 3.48 mg/d, respectively. The yield was 7325.10kg/1000m², obviously higher than others.2 By means of quadratic general rotational combination design under the condition of plastic greenhouse, the comprehensive effects of nitrogenous fertilizer, phosphor fertilizer, potassium fertiliz er and water on onion yield was studied, the regression models between yield and application amo unt of nitrogen, phosphor, potassium, and water was establishing. The model was as follow:Y=7643.83965+258.74951Z₁+386.73447Z₂+381.94090Z₃+495.26814Z4-711.6986Z₁²-403.71471Z₂²-2 87.43453Z₃²-264.64978Z₄²+13.88815Z₁Z₂+119.44457Z₁Z₃+120.00082Z₁Z₄+120.00082Z₂Z₃+119.44457Z₂Z₄+13.88815Z₃Z₄Analysis result showed that the effects of four factors on onion yield were closed; effect of t he amount of water was a little great than others.According to the model the optimal combination of these factors were proposed according to different levels of yield of onion. The highest yield of treatment was that Z₁=0(application N 18.2 7kg/1000m²), Z₂= 1.000(application P₂O₅ 14.4kg/1000m²), Z₃=1.000(application K₂O 10.56kg/1000m²) Z₄=1.000(water application 559.45m³/1000m²)There was significant interaction between the two of these facts. When the codes of N and P, N and K, N and water, P and K, K and water were lower than 0.1865 and 0.4816,0.2418 and 0.7149,0.2658 and 0.9960,0.5962 and 0.7889,0.63871 and 1.07984,0.6874 and 0.9537,respecti vely, they had positive correlation. When the codes were higher than those, they had negative corr elation.By simulation with computer, the plan of irrigation and fertilizers of onion yield exceeding 6653.72...