Suitability Evaluation Of Agro-geological Environment For Chinese Chestnut In East Area Of Beijing

Jing Dong Chestnut, which is often described as "pearl" and "purple jade", enjoys avery high reputation in international market. Jing Dong Chestnut also has very higheconomic value and it's the main agricultural produce which is exported to gain foreignexchange. But recent years, in the process of Chestnut planting, the fruit growers alwaysconcern about the yield and ignore the quality of chestnut, therefore the quality ofchestnut had dropped. In view of this problem, we carried out the investigation about theplanting condition, growth situation, fruit quality and agro-geology environment of JingDong Chestnut. We adopted the method of combination of the AHP method and thefuzzy synthetic evaluation method to discuss the agro-geology environment suitabilityevaluation of Chinese chestnut, and regression analysis to discuss the relationshipbetween geochemistry element and fruit quality. The result shows:(1)According to the investigation and analysis about the chestnut in Qian Xi, ZunHua, Kuan Cheng and Xing Long, we knew the planting area in these counties are: 3.67×10~4hm~2, 2.13×10~4 hm~2, 2×10~4 hm~2, 2.73×10~4 hm~2 and the yield are: 1.6×10~4t/a,1.23×10~4t/a, 0.8×10~4t/a, 3.3×10~4t/a; and the main problem are absence of reasonableprogramming when expanding chestnut planting and the appearance of empty nuts andyellow leaves.(2) Establish the agro-geology environment evaluation system of chestnuts in theeast of Beijing. Determine the pH value, the parent material litho logical character, thevariety, the organic matter, the slope, the character of surface soil, the soil type, theelevation,＞10℃accumulate temperature the irrigation, the organic fertilizer investment,the thickness of soil layer, the tree condition, the slope orientation, the soil bodyconfiguration and the terrain as the evaluation parameters, established the subjectiondegree for each index, and evaluated every investigation spot and mark them. Accordingto the synthetical scores, gathered the similar kinds and did compositor, we classified theinvestigation area as: the suitable area, the sub-suitable area and the unsuitable area.(3) According to the simple correlation analysis and regression analysis betweenchestnuts nutrition quality and soil element, we got the linear regression equationbetween Jing Dong Chestnut's single seed weight, gelatinization temperature, starch,Vitamin C, reducing sugar, yield and the content of available form of each element, andused iterative methods work out the optimum element contents which affect the JingDong Chestnut's quality are: available potassium 80 mg/kg, available iron 23 mg/kg,available manganese 30 mg/kg, available cupper 1 mg/kg, available zinc 4.3 mg/kg, available lead 0.8 mg/kg, available calcium 85mg/kg, available magnesium 12 mg/kg,available boron 0.34 mg/kg.(4) In the methods of evaluation and statistics mentioned above, we found that, factoranalysis method can be used to screen index, cut down analytical workload; the methodof combination of the AHP method and the fuzzy synthetic evaluation method will beappreciated when more qualitative indexes should be used in the suitability evaluation ofagro-geology environment; in correlative research, the regression analysis has itsadvantage when we use it to eliminate variables and pursuing variable index which hasmaximal effect on dependent variable.