海南琼中橡胶林土壤磷储量研究

磷是植物生长不可缺少的大量营养元素,研究琼中橡胶林土壤磷储量及分布规律有利于指导施肥,并对热带地区主要橡胶林土壤磷循环研究具有特殊意义。对海南琼中6个龄级(5、10、15、20、25、30年)的橡胶林土壤(土壤分级:0～20、20～40、40～60、60～80、80～100 cm)进行调查采样,室内测试分析其磷含量,计算土壤各个层次的磷储量。研究结果表明:(1)琼中橡胶林土壤全磷含量为57.68 mg/kg,有效磷含量为2.25 mg/kg,全P含量在土壤剖面中无明显的分布规律,有效P含量大致随剖面深度的增加而减少;(2)琼中橡胶林土壤全磷总储量为843.25 kg/hm2,有效磷储量为32.12 kg/hm2。20～40 cm的全磷储量和有效磷储量均最大,分别占31.18%和28.18%。琼中橡胶林土壤总体处于缺磷状态,有必要增施磷肥或复合肥。

Phosphor Reserves of Rubber Plantations in Qiongzhong,Hainan Island

Phosphorus(P) is indispensability nutrient for vegetation growth.Research on the soil′s P reserves and distribution rule is good for guiding fertilization,and makes special sense to the soil’s P cycle of main rubber plantations of tropical region.The rubber plantations are divided into six age levels which are 5 year-old,10 year-old,15 year-old,20 year-old,25 year-old and 30 year-old,and the soil is divided into 0～20 cm,20～40 cm,40～60 cm,60～80 cm,80～100 cm.The six age-level rubber plantations in Qiongzhong were investigated and sampled,testing and analyzing phosphor content indoor and then phosphor reserves of each layer can be gained.The results list as follows:(1) The soil’s total P content of rubber plantation in Qiongzhong was 57.68 mg/kg,and the efficiency P content was 2.25 mg/kg.The total P content had not obvious distribution rule in the section plane,but the efficiency P content decreased with the increase of soil depth;(2) The soil’s total P reserves of rubber plantation in Qiongzhong was 843.25 kg/hm2,and the efficiency P content was 32.12 kg/hm2.The total and efficiency phosphor reserves of 20～40 cm were all the biggest,accounted for 31.18 and 28.18% respectively.The soil of rubber plantations in Qiongzhong was under the condition of lacking P collectively,it was necessary to fertilize with P or compound fertility.