Study On Garlic Planting Regionalization Based On The Geochemistry Survey Results

The content of chemical elements in soil have important influence upon the crop’sproduction and quality. Land ecologic suitability evaluation based on soil chemical elements canguide agricultural production and help to develop characteristic agriculture. It has a practicalguiding significance using multi-target geochemical survey to carry out a thorough investigationon garlic planting regionalization.Taking the Kaifeng city for example, it has carried out the garlic planting regionalizationbased on the geochemical survey. First of all, the research used statistical analysis andgeostatistical analysis to find out background characteristics, abnormal value, spatial distributioncharacteristics and abundance or deficiency condition of the soil geochemical elements in thestudy area. After that the atmosphere,water and soil environment quality condition the analysis inthe study area were analyzed, these regions would be classified into temporary unsuitable zonewhich not be in line with the requirement of air and water environment quality in greenagricultural products (garlic) as polluted soil. Based on this, according to the main influencingfactors affect the garlic’s quality and growth, the soil site conditions, irrigation management leveland soil geochemical elements, a total of11indexes were finally selected. And then takingadvantage of analytic hierarchy process (AHP) to determine index weight and constructedmembership function to calculate the membership degree, afterwards through the weighted indexand model to calculate the garlic planting suitability composite index and according to it’shistogram natural cracks, the study area was be divided into4suitability grades. Finally in thelight of the garlic planting suitability grades grades results, the evaluation results were partiallyvalidated in a small experimental field, and then suggestions for the garlic planting layoutadjustment, fertilizing, farmland management, planting industrialization and marketization wereput forward.The main conclusions are as follows:(1) According to the1:250000multi-purpose geochemical survey data, the surface soilelement contents of I, Cl, S, P, C, K2O, Na2O, CaO and Sr in Kaifeng city are higher than otherareas’ in Henan province, the deep soil element contents of Cl, S, P, Na2O, C, CaO and Sr are alsohigher than other areas’, while the content of I in deep soil significantly lower than other areas. Some of these elements in Kaifeng city are relatively concentrated distribution, such as S elementin the surface soil, it’s higher in the northeast, central and southeast areas while lower in the northand west areas of Kaifeng city, which laid a solid foundation for building the garlic plantingsuitability evaluation system based on the geochemical elements.(2) The air, irrigation water and soil environmental quality in Kaifeng city were analyzed andevaluated, the results shows that the average annual air quality in recent years in Kaifeng city isalmost conform to the air environmental quality requirements of the green agricultural products,agricultural production is mainly to prevent accidental sand disasters; In most regions of Kaifeng,the pH, heavy metals and F element indexes of the farmland irrigation water generally conform tothe requirements of green agricultural products environmental quality, while the groundwatermineralization degree is higher in local area of Lankao, Kaifeng, Weishi; The soil environmentalquality were polluted in Dongjiao village and Nanjiao village of urban areas, which are notsuitable for agricultural production.(3) After considering all factors, soil texture configuration, irrigation guarantee rate, drainagecapability, pH, Corg, P, K2O, S, Cu, Zn and Mn11indexes were selected and garlic plantingsuitability evaluation index system was constructed. The evaluation results showed that garlicplanting high suitable areas are117829.83hm2, moderately suitable areas are355912.93hm2,barely suitable areas are113373.22hm2, temporarily unsuitable areas are9640.07hm2in Kaifengcity. Among them, high suitable areas are mainly distributed in QiXian, about44943.85hm2. Inthe present garlic planting areas, temporarily unsuitable areas which need to be abandon are2282.50hm2; Barely suitable areas are3560.38hm2, moderately suitable areas are77712.18hm2,highly suitable areas are30881.74hm2, which will keep continuing to plant garlic.(4) Some soil element content in the study area are lower. In the surface soil, the averagecontent of B, Ni, Zn, Mn, Cu, Fe, I are lower than the Henan province and the nationalbackground values. Only the average content of Mo slightly higher than the Henan provincebackground value but still below the national background values. On the basis of this condition,the micronutrient fertilizer with N, P and K was put forward for the garlic cultivation.