Water And Fertilizer Coupling Effects On Camellia Oleifera Growth Traits And Soil Properties

In this experiment, production and research base in Fengcheng, Jiangxi province was usedas a experimental plot, with7-year-old Camellia as test material, the coupling effects of waterand chemical N and K fertilizers on latex yield were studied by general orthogonal rotationdesign of quadratic regression with three factors and five levels under field condition. StudiedCamellia oleifera each growth index changes, Camellia fruit yield and economic characters inone growing season, nutrients traits of different soil layers and their dynamic changes, at last setup a regressive mathematical model of the latex yield by quadratic regression analysis, to find themost optimal combination of design and guide the high-yielding and efficient production ofCamellia oleifera. The results as follows:（1） After different combination treatments of irrigation and fertilization, the plant height,crown and fruits of economic traits had significant differences. The tree high and crown growthrate of treatment13were the highest, they respectively were20.2%and19.2%; the tree high andcrown growth rates of the treatment CK were the lowest, they respectively were12.9%and7.7%.（2） The N、P、K nutrient contents of Camellia leaves had no significant difference betweendifferent treatments. The Camellia leaf nitrogen percentage of different water and fertilizertreatment were more than the CK treatment in the time of May and September, the leaf nitrogenpercentage of treatment4in December was the lowest （1.92%）; the leaf nitrogen percentage oftreatment3in December was the highest （2.57%）. With the change of time from May toDecember Camellia leaf nitrogen percentage decreased first, then increased as a whole, while thephosphorus percentage had an opposite trend.（3） The average fruit diameter of treatment10was the maximum （3.65cm）; while averagefruit diameter of the CK was the minimum （2.79cm）. Camellia fresh fruit oil content of eachtreatment was between6.99%to11.01%, the fresh fruit oil rate of treatment3was the highest（11.01%）; the fresh fruit oil rate of treatment11was the lowest （6.99%）.（4） Different soil layer pH values of each treatment had no significant difference, but overallshowed that surface soil （0-10cm） pH values were low, the pH values of middle layer soil（10-20cm） and subsoil （20-40cm） had high trend. Each treatment pH value of upper soil inSeptember was the minimum. Under the conditions of high soil nutrient content and highfertilizer application amount, the order of water, nitrogen, potassium that affects Soil pH valuewas: W> N>K.（5） Different soil layers organic matter percentage and available nutrients were significantlydifferent of each treatment, the order of different soil layers Camellia woodland soil organicmatter percentage and available nutrients was: upper> middle> lower. The difference of eachtreatment upper soil organic matter percentage was decreased, while the middle and lower soilorganic matter percentage tended to increase in September. The hydrolysis nitrogen contents ofeach treatment upper soil changed over time generally decreasing trend after the first increase, phosphorus content was relatively stable, K content changed over time generally reduced andthen slightly positive trend.（6） Regression model was established on the basis of the optimal solution, the best ratio offertilization and irrigation can be obtained by the following regression equation:Y=2.5695+0.2377X₁+0.2035X₃+0.115X₁X₃-0.2694X₁²-0.2983X₂²-0.1654X₃²The regression relationships reached a significant level. Within the scope of experimentaldesign, nitrogen, potassium and moisture factors had a significant positive-effect on Camelliayield, the order of affects of three factors was: N （X₁）> K （X₃）> W（X₂）. The single-factor yieldeffects model found that they were the highest Camellia production when the nitrogen fertilizer,potash fertilizer and irrigation application levels reached0.441,0.615and0. The two-factorcoupling effect analysis found that the interaction between nitrogen and potash fertilizer wasgreater, followed by nitrogen and water, water and potash fertilizer interaction was the smallest.The best Camellia yield treatment options of nitrogen, water and potassium levels were: N（X₁）=0.618, W（X₂）=0and K（X₃）=0.830. That was, Nitrogen fertilizer （urea）0.424kg per plant,irrigation125L per plant, potassium fertilizer （potassium chloride）0.830kg per plant, and thehighest yield of Camellia was2.727kg per plant.