Effects Of Pipeline Infusion & Drip Irrigation With Fertilization On The Soil And Tree-growth Of Longan Orchards

In the face of various problems such as short water resource and soil pollution induced by increasingly low utilization rate of fertilizer, it is the most important issue for the orchards to deal with that how to improve the utilization rate of water and fertilizer. During March,2013 to August,2014, this study was did in the sample orchard of agricultural college of Guangxi University that "Shi Xia" were used as experimental materials. The major research contents were the impact of soil in longan orchard, leaves of longan, character of shoots, growth and development of fruit, fruit quality and output induced by the fertigation mode of infusion drip. The results received in this study were as follows:1 Infusion drip fertigation improved the soil physical and chemical properties. The soil water content in 0-60cm soil layer of pipeline infusion & drip irrigation were all higher than pipeline infusion and all the treatments were similar under 80cm soil layer, overall fluctuations from 15% to 35%. The pH of pipeline infusion & drip irrigation were all lower than pipeline infusion in 0-100cm layer, but pipeline infusion & porous drip fertigation was relatively high compared with the others in 0-80cm soil layer. The content of total nitrogen, total phosphorus, total potassium in 0-20cm and 20-40cm were all improved compared with pipeline infusion. The content of soil organic matter available nitrogen, available phosphorus and available potassium in 0-100cm soil layer were all showed a trend of decline of all the treatment, mainly distributed in 0-60cm soil layer, and they were similar in 60-100cm soil layer, the soil organic matter content of pipeline infusion & drip fertigation and pipeline infusion & porous drip fertigation were relatively high in 0-20cm soil layer, pipeline infusion &-10cm drip fertigation and pipeline infusion & -20cm drip fertigation are higher in 20-40cm soil layer.2 Infusion drip fertigation improved the nutrient conditions of Longan trees. Infusion drip fertigation improved transmission characteristics of longan leaf, and the effect of pipeline infusion & -20cm drip fertigation and pipeline infusion & porous drip fertigation is most obvious. The increment of length and diameter of new branch about pipeline infusion & porous drip fertigation were both the hightest. The increment of SPAD were increased respectively. The original light energy conversion efficiency is higher and habitat adaptability is stronger of pipeline infusion & porous drip fertigation, the fluorescence yield is the hightest of pipeline infusion & porous drip fertigation when the PS11 reaction in a fully closed, also, potential reaction activity is strongest, and the part of energy used for photosynthetic electron transport from the absorption of light energy is the most. The distribution of fresh root weight the total number of roots in 0-40cm soil layer was more and in 40-60cm soil layer was less.3 Porous drip fertigation promoted the growth and development of Longan fruit. Surface porous drip fertigation is the best way of fruit transverse and longitudinal diameter growing. Surface porous drip fertigation was more conducive to more starch accumulated in longan fruit being translated into soluble sugar.In the process of upgrowth of fruit treated by conventional soil fertigation, pipeline infusion fertigation and surface porous drip fertigation, the content of Vc tend to constantly increasing and increased quickly after fruit sets 80 days. The content of titratable acid tend to increasing firstly and decreasing later and the titratable acid content of pipeline infusion fertigation and surface porous drip fertigation is lower than that of conventional soil fertigation when the fruit ripe. The accumulation of soluble solids are mainly concentrated in the late stage and increased rapidly after 70 days of fruit set, pipeline infusion fertigation and surface porous drip fertigation were beneficial to the improvement of the longan soluble solids content.4 Infusion drip fertigation increased the yield and quality of Longan fruit. Infusion drip fertigation improved the vertical and horizontal diameter of the fruit, edible rate, content of soluble solids, soluble sugar and vitamin C, single panicle weight, the number of panicles per plant, and the physical production per plant, pipeline infusion & -20cm drip fertigation and pipeline infusion & porous drip fertigation were better choices.