刺激割胶制度对广东植胶区胶园土壤养分的影响

对实施刺激割胶制度后广东植胶区胶园的土壤养分状况进行分析,并与实施刺激割胶制度前胶园的土壤养分的状况进行比较。结果表明:在实施刺激割制14a后,胶园的土壤养分总体水平比较低,其中花岗岩赤红壤和砂页岩赤红壤中的有机质、全氮、有效磷和有效钾的含量均低于正常值的下限;玄武岩砖红壤中的有机质、全氮和有效磷的含量在正常值范围内,而有效钾的含量低于正常值下限。说明现行胶园培肥等管理措施已不能满足刺激割胶制度下的橡胶树正常生长、生产的需求。在刺激割胶制度下,胶园土壤中的有机质、全氮、有效磷、有效钾、速效氮和pH等6种指标是影响橡胶树产量的主要因素。胶园土壤pH在下降,胶园土壤有呈酸化的趋势。

Effect of Stimulated Tapping Systems on the Soil Nutrient Status of Rubber Plantations in Guangdong State Farms

In Guangdong state farms, 142 soil samples were collected and analyzed for the rubber(Hevea brasiliensis) plantations under stimulated tapping systems, s/2 d/(3~5) ET. The soil nutrients were compared with those in the past. The results showed that the level of soil nutrients in the rubber plantations was low after 14 years of adopting stimulated tapping systems. The contents of OM, total N, available P and available K in the rubber plantations on latored soil derived from sand-shale and granite were lower than the lower limit of the normal value. The contents of OM, total N and available P in the rubber plantations on basalt laterite fell within the normal value, but the content of available K was lower than the lower limit of the normal value. Most of the soil nutrient contents were also lower than those of the rubber plantations under traditional tapping systems, s/2 d/2, in 1975. This implied that the current management measures for the rubber plantations could not satisfy the requirement rubber trees for their normal growth and production under stimulated tapping systems. Meanwhile, six soil nutrients, i.e. OM, total N, available P, available K and pH, were found major factors to affect the rubber yield. The soil pH was declining in the rubber plantations under stimulated tapping systems, indicating soil acidification.