The Nutrient Diagnosis Of Toona Sinensis Plantation In Xingwen County

Toona sinensis rapid growth, high yield, root system, lush foliage,Not only can be used as timber, its buds are also excellent forest vegetables, but also has ecological functions such as soil and water conservation, is the primary election species of Grain for Green Project, is also a major forest tree species rich farmers.According to the survey, Sichuan Xingwen County introduced since 2003 in the Grain for Green Project in timber Toona sinensis, currently growing larger, but the prevalence of extensive management, forest clear differentiation, stand phenomena such as low productivity, therefore, to carry out Xingwen County Toona sinensis plantation nutrient diagnosis, improve plantation management level, to further consolidate the results is the Toona sinensis plantation Grain production process need to be resolved a major issue In this study, artificial Toona sinensis forest in Xingwen County as the research object, according to stand age, stand growth conditions to establish 20m×20m standard 29, combined with the analysis of field investigation and laboratory test, the analysis of soil and plant analysis, get the Toona sinensis plantation nutrient supply situation and the mutual relationship between nutrients, thus the establishment of effective Toona sinensis plantation nutrient diagnosis standard. The results are as follows:1,Correlation analysis to obtain:(1)Soil available K, exchangeable Ca, available Fe, effective Mn are the main limiting factor for Xingwen County Toona sinensis plantation production volume, total N and hydrolysis N are secondary limiting factor, organic matter, total P, effective P, full-K, effective Mg, effective Cu, effective Zn are non-limiting factor. (2)ln Toona sinensis leaf nutrient elements affecting production stands indicator is N, P, K, Cu, Zn, Mn, these elements can be regarded as Toona sinensis leaf Nutrients in sign. (3)In the balance relationship of theToona sinensis leaf nutrient elements,the balance between K, Ca, Cu, Fe, Zn, Mn with other elements of a large amount of influence on the stand of the production, showed high concentrations of Cu and low concentrations of Fe, Zn, Ca, Mn, K conducive Toona sinensis tree height, diameter and stand volume growth. (4)There is a synergistic effect between N and Cu, K and Mn, Cu and Mn, Fe and Zn, an antagonistic effects between P and Ca, K and Mg, Cu and Zn in leaf nutrient elements.2,In the diagnosis method by the critical concentration, respectively based on height, diameter, volume index, effective diagnosis get optimal value and optimum nutrient concentrations of N, P, K, Cu, Zn, the results have practical value; Additionally, Mg and Fe because the correlation was not significant, the optimum value and the optimal nutrient concentrations low confidence, not a reference value; Ca and Mn due to the corresponding regression equation is invalid, therefore can not be diagnosed.3,DRIS method to get:(1)Selected N,N/Cu, N/Mn, P/Ca, P/Cu, K/Mg, K/Cu, Ca/Mg, Ca/Cu, Ca/Zn, Mg/Cu, Cu/Fe, Zn/Cu, Zn/Mn, Mn/P 15 indicator of leaf nutrient concentration or concentration ratio.(2)Xingwen County Toona sinensis plantations overall performance of nutrient imbalance, where P, Cu, Fe showed insufficient, Mn manifested as excessive or even causing excessive toxicity, N, K, Ca, Mg, Zn is mainly for relatively plentiful. Therefore Toona sinensis plantation fertilization management measures should be applied P, Cu, Fe fertilizer, less fertilizer applied or not applied Mn. (3)The appropriate concentration range of Toona sinensis plantation leaf nutrient elements are N: 13.860-21.812g/kg; P:1.914-3.412g/kg; K:9.172-18.170g/kg; Ca:20.457-49.483g/kg; Mg: 4.143-6.893g/kg; Cu:5.601-11.107mg/kg; Fe:84.584-493.016mg/kg; Zn:16.897-34.939 mg/kg; Mn:74.319-123.753mg/kg.