Study On Water And Nitrogen Coupling Using Response Of Young Camellia Oleifera Abel’ S Growth And It’s Soil

Camellia(Camellia oleifera Abel) is one of the most important woody oil crops in south China. It has important economic value. There are many problems in the cultivation and fertilization of Camellia. To solve those problems a two-factor split-plot experimental design was used in this paper. The two factors are water and nitrogen fertilizer. Water is the main area factor. There are three levels of irrigation water: 0, 30, 60 kg·plant-1. Nitrogen application was the deputy district factor. There are three levels of nitrogen application: 0, 60, 120, 240 g·plant-1. The amount of Phosphate fertilizer and potash was the same in each treatment. Design 12 treatments to research the effects of water and nitrogen coupling using on the growth of young camellia and the soil physical and chemical properties in different seasons. The main results are as follows:(1) Water and nitrogen coupling using is helpful to improve the plant height, ground diameter and leaf SPAD value of camellia compared with the control group. Under the condition of same amount of nitrogen fertilizer, the plant height, ground diameter of camellia increased with the increasing amount of irrigation water; This trend is also applicable for the growth of the plant height, ground diameter of camellia; Under the condition of same amount of irrigation water, the growth of the plant height of camellia increased with the increasing amount of nitrogen fertilizer firstly. Then the growth of the plant height of camellia decreased with the increasing amount of nitrogen fertilizer; the growth of the plant height of camellia is the biggest under the treatment of 120 g·plant-1; the ground diameterand leaf SPAD value of camellia increased with the increasing amount of nitrogen fertilizer.(2)The seasonal variation trend of the content of soil alkali-hydrolysable nitrogen, total nitrogen, organic matter was the same under different water and nitrogen conditions. At the end of June, the content of soil alkali-hydrolysable nitrogen, total nitrogen, organic matter was the highest and at the end of December, the content of soil alkali-hydrolysable nitrogen, total nitrogen, organic matter was the lowest. Under the condition of same amount of irrigation water, the content of soil alkali-hydrolysable nitrogen, total nitrogen increased with the increasing amount of nitrogen fertilizer in four seasons; the content of soil organic matter increased with the increasing amount of nitrogen fertilizer(from the amount of N application 0 to 120 g·plant-1), then the content of soil organic matter decreased in the treatment of N4(240 g·plant-1). Under the condition of same amount of nitrogen fertilizer, the content of soil alkali-hydrolysable nitrogen, total nitrogen, organic matter didn’t change regularly with the increasing amount of irrigation water in four seasons.(3) Under the condition of same amount of irrigation water, the activity of soil urease, soil phosphatase increased with the increasing amount of nitrogen fertilizer(from the amount of N application 0 to 120 g·plant-1), then the activity of soil urease, soil catalase and soil phosphatase decreased in the treatment of N4(240 g·plant-1). In the treatment of W1(0 kg·plant-1) and W2(30 kg·plant-1), the activity of soil sucrase increased with the increasing amount of nitrogen fertilizer(from the amount of N application 0 g to 120 g·plant-1), then the activity of soil sucrase decreased in the treatment of N4(240 g·plant-1). In the treatment of W3(60 kg·plant-1), the activity of soil sucrase increased with the increasing amount of nitrogen fertilization in four seasons. Under the condition of same amount of nitrogen fertilizer, the activity of soil urease and catalase decreased with the increasing amount of irrigation water in four seasons. The activity of soil sucrase decreased with the increasing amount of irrigation water in treatments of N1(0 g·plant-1), N2(60 g·plant-1) and N3(120 g·plant-1). In the treatment of N4(240 g·plant-1), the activity of soil sucrase increased with the increasing amount of irrigation water. In the treatment of N1(0 g·plant-1), the activity of soil phosphatase decreased with the increasing amount of irrigation water. In the treatment of N2(60 g·plant-1), N3(120 g·plant-1) and N4(240 g·plant-1), the activity of soil phosphatase increased with the increasing amount of irrigation water then decreased.(4) The best water and nitrogen applying using as the object, the growth index, soil nutrient content, soil enzyme activity as the contestant indexes, after comprehensive evaluated the different treatments, the result is when water 30 kg·plant-1, nitrogen application rate at 0-120 g·plant-1 can not only improve the soil nutrient content and enzyme activity, but also promote the growth of camellia.