景洪市茶园土壤养分状况分析OA

This study was based on 90 soil samples from tea gardens in Dadugang Township,Puwen Town,Mengwang Township and Jino Township of Jinghong City.The Mehlich-3 extraction method combined with ICP-AES analysis was adopted,and a hierarchical evaluation system was used to systematically reveal the distribution characteristics of soil nutrients and the main limiting factors.The results indicated that soil acidification was relatively severe in the region.The lowest average soil pH value was recorded in Mengwang Township(4.20),with 37.50%of the samples being strongly acidic(pH<4.00).In contrast,the soil pH in Jino Township was optimal(average of 4.90),with all samples meeting the standards for high-quality tea gardens(4.50-5.50).Soil organic matter showed a two-pole differentiation.The highest content of organic matter was observed in Dadugang Township(average of 34.10 g/kg),where 88.37%of the sample met the Grade I.The lowest content of organic matter was found in Jino Township(average of 13.75 g/kg),with 50.00%of the samples classified as Grade III),mainly due to slope erosion and uneven fertilization.Total nitrogen was generally sufficient across the region(1.19-2.76 g/kg),with 87.50%of the samples reaching Grade I.However,structural imbalances were observed in available phosphorus and potassium.75.00%of the samples in Mengwang Township were deficient in available phosphorus(average of 14.13 mg/kg),while 50.00%of the samples in Jino Township had available phosphorus below 5 mg/kg.Potassium deficiency was identified in 41.86%and 50.00%of the samples from Dadugang Township and Jino Township,respectively,requiring urgent attention.Synergistic deficiencies in calcium and magnesium were obvious.Over 83.00%of the samples in Dadugang Township and Puwen Town were simultaneously deficient in both calcium and magnesium,with imbalanced calcium/magnesium ratios(e.g.,6.47 in Dadugang Township).Regarding micronutrients,iron and manganese were enriched,while copper and zinc were deficient.Available iron was highly enriched throughout the region(165.05-512.65 mg/kg),far exceeding the critical requirement.Available copper was seriously insufficient(average of 0.67-0.81 mg/kg in three townships),with more than 62.50%of the samples classified as"highly deficient".Available zinc was critically short(0.85-1.42 mg/kg),with Mengwang Township being the most typical.It is suggested to implement a zonal regulation strategy:soil acidification improvement and organic matter enhancement should be prioritized in Mengwang Township;phosphorus and potassium supplementation should be strengthened in Jino Township;synergistic regulation of calcium and magnesium should be promoted throughout the region,with magnesium supplementation in low-magnesium areas and magnesium reduction coupled with calcium increase in high-magnesium areas;and chelated microfertilizers should be applied in copper and zinc deficient areas to improve nutrient efficiency.The results provide a theoretical basis and technical support for the scientific management and sustainable development of tea garden soil nutrients in tropical regions.