| Investivation of the soil physicochemical properties is the important basis for guiding orchard fertilization, the analysis of the leaf nutrient elements is the direct means of fruit tree nutrient diagnosis,Standard value method achieve the fruit tree nutrient diagnosis by means of the analysis of leaf nutrient element content. In this experiment, we make an investivation and evaluation to the physicochemical properties of soil that collecting from litchi orchard in the Midwest of Hainan.Main results are as follows:1. The soil PH of litchi orchard in the Midwest of Hainan is in the range of4.74to6.41,83.87%of the soil pH is between4.5to5.5for the strongly acidic.2. The organic matter content of litchi orchard in the Midwest of Hainan is between3.08to23.50g/kg, which is mainly concentrated in the fourth grade, and the ratio is67.74%. The content of total N ranges from0.09to0.86g/kg, and the average value is0.60g/kg, It is the content of total N that is mainly distributed in the fourth, fifth, and sixth grades, respectively, the ratios are32.26%\38.71%and29.03%. Alkaline hydrolysis N content is generally low, ranged from17.08-137.66mg/kg, the average concentration of78.60mg/kg, mainly distributed in the third, fourth, fifth grade, three levels accounted for77.42%of the analyzed sample,available P ranged from0.98to62.20mg/kg, the coefficient of variation was84.05%, mainly distributed in two, four and six level, the sample size of the survey,25.81%,22.58%and22.58%. The available K ranged from19.25-296.97mg/kg, the average concentration of108.77mg/kg, and the coefficient of variation was71.29%, one, five and six are16.13%proportion, two, three and fourlevel of12.90%,9.68%and29.03%, respectively.3. Observation plantation soil, the content of trace elements:soil exchangeable Ca ranged from11.78to1326mg/kg, the coefficient of variation of115.37%,74.19%of the plantation is in the fifth grade. Exchangeable Mg content ranged from1.00to87.40mg/kg, the average concentration of61.45mg/kg, the coefficient of variation of118.22%, mainly concentrated in four, five and six levels, namely the number of survey sample32.26%,32.56%and25.81%. Active Fe content is more abundant, the average content of40.65mg/kg, and the content for the first level,the level of the proportion of96.6%. The available Mn average content of34.04mg/kg, the coefficient of variation was65.81%, only distributed in one, two, three level, the proportion was40.7%,37.2%and22.1%. The effective average Cu content of1.69mg/kg and ranged from0.31to3.00mg/kg, the coefficient of variation was68.06%, soil Cu content of72.3%, higher than the secondary standard. The mean effective Zn content of23.65mg/kg, and its content in the range of13.80to38.55mg/kg, more than90%of soil available Zn content of a standard.4. Observation plantationl litchi garden soil total N, alkaline hydrolysis N, available P and available K content is low, Fe, valid the Zn and effective Mn content is rich, which could be able to meet the needs of normal growth of litchi plants. Exchangeable Mg content is low, all orchards that we have surveyed can not meet the need for the growth of litchi without fertilization. There are35.48%samples’ exchangeable Ca content can not meet the need of normal growth. It is necessary for strengthening the application of nitrogen, potassium, phosphorus, calcium and magnesium in the process of litchi cultivation.5. The change law of leaf nutrient elements in litchi growth cycle:the centent of N has little change from the bud differentiation period to fruit maturation period, and it reachs the highest level in the aging time. The content of P and K have the similar variation trends,which decline in the bud differentiation period, drop to the first low value in florescence period. and rise to the maximum value in fruit maturation period, and the aging time has the minimum value. Lai Ca and Mg trend similar to the slow rise in the flower bud stage to the flowering stage, fruits mature late highest content, in autumn a little aging to a minimum value. Zn and Fe similar trend, the highest content of flower bud differentiation stage, flowering small decline, rebounded content of fruit ripening and fall slightly aging of the lowest content. B and Cu content similar trend, the content of flower bud differentiation stage, autumn slightly aging of the lowest content.6. Soil elements and plants elements significantly negative related to the as: alkali solution of NP, Fe-B effective; the elements in the soil and plants elements extremely significant with a positive correlation of as:full nn; elements with plants in the soil inelements are:effective Zn-n, exchangeable Mg-Zn; A significant positive correlation effective Zn-P effective PK, a fast-acting K-Fe, N-Ca, N-Mg, N-Fe, soil and plants element content was not significantly related, determination of soil nutrient content alone can not accurately plant nutrition elements to judge the gains and losses of soil nutrients, chemical analysis values should be used as adjunct leaf analysis, a comprehensive analysis to a comprehensive description of the nutritional status of the plant.7. Initially identified Fei zi xiao flowering and fruit ripening late as the nutrition diagnosis period. Nutrition Diagnosis of flowering suitable range of N:16.019.0g/kg, P:0.9to1.2g/kg, K:7.0to11.0g/kg, Ca:5.0to11.0g/kg, Mg:1.5to3.0g/kg, Fe:60.0-140.0mg/kg, Cu:4.0～9.00mg/kg, Zn:15.0～64.00mg/kg, B:3.00～18.00mg/kg. Fruit ripening late nutrition diagnosis suitable range of N:12.022.0g/kg P:0.8to1.2g/kg, K:10.015.0g/kg, Ca:6.0to21.0g/kg, Mg:1.56.0g/kg, Fe:60.0～170.0mg/kg, Cu:3.5～10.0mg/kg, Zn:25.0～75.0mg/kg, B:5.0-15.0mg/kg.8. Llitchi garden yield blade suitable content ratio for the N:P:K:Ca:Mg=1.00:0.06:0.51:0.46:0.13; Fe:Cu:Zn:B=1.00:0.07:0.40:0.11. Suitable content of the leaves of fruit ripening late than for the N:P:K:Ca:Mg=1.00:0.06:0.73:0.79:0.22; Fe:Cu:Zn:B=1.00:0.06:0.43:0.09. |
