勐海县甘蔗土壤养分空间分布特征及肥力评价

对勐海县10个甘蔗生产乡镇进行土壤调研取样,共采集0～20 cm土层样品200份,测定了土壤pH、有机质、碱解氮、有效磷、速效钾、交换性钙和交换性镁含量,运用ArcGIS的Kriging插值法分析了蔗区土壤肥力现状与空间分布特征,并采用改进后的Nemerow综合指数法评价了土壤的肥力等级.结果表明:勐海县蔗区土壤主要为...

Nutrient Spatial Distribution and Fertility Evaluation of Sugarcane Soils in Menghai County

Sugar industry is the main pillar industry in Menghai County, Yunnan Province. A soil survey in the sugarcane area of Menghai County will help to understand soil nutrient status, and thus provide data support for soil improvement and precise fertilization in sugarcane production. This study conducted field survey in 10 sugarcane producing towns in Menghai County, and a total of 200 soil samples from the 0-20 cm soil layer were collected to determine the soil pH, organic matter, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, exchangeable calcium and exchangeable magnesium levels. Then ArcGIS Kriging interpolation method was used to study the nutrient spatial distribution characteristics, and improved Nemerow comprehensive index method was applied to evaluate soil fertility status. The results showed that the sugarcane area of ??Menghai County predominated with acid soil, with soils having pH of 4.5-5.5 accounting for 73.5%, and soils with pH<4.5 accounting for 9.5%. Soil organic matter, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, exchangeable calcium and exchangeable magnesium were generally high, and the proportion of soils in the medium and high grades were 88.5%, 83.5%, 71%, 91.5%, 73.5%, and 85%, respectively. The results of spatial distribution analysis displayed that the soils in the south of Menghai County had higher pH levels, while low levels of organic matter, alkali-hydrolyzable nitrogen, available phosphorus, available potassium mainly occurred in the west and south towns, and low levels of exchangeable calcium and exchangeable magnesium were mostly in the northwest and middle-east towns. The comprehensive soil fertility index was 1.52, and thus the fertility of soils in sugarcane area in Menghai County was evaluated as grade II, indicating a middle to high fertility level. In conclusion, soils in sugarcane area of Menghai County are mainly acidic and the fertility levels in most towns are generally high, with only a few towns having relatively low levels, which suggests a generally suitable soil nutrient condition for sugarcane production.