Spectral reflectance characteristics of laterite for rubber plantation in Hainan Island

【Objective】 In order to supply classification indicators of soil spectrum for the classification of soil in rubber plantation, the spectral reflection characteristics of latosol in rubber plantation were analyzed. 【Method 】By the methods of collecting soil spectral reflectance using ACD and analyzing indoor,the spectral reflection characteristics were analyzed based on soil nutrition content and soil spectral reflection. 【Result】The reflectivity spectrum curves of laterite developed from different parent materials in Hainan rubber plantation presented to be similar. There was obvious absorption valley at 1400, 1900 and 2200 nm, except the curve of Jialai farm in which the moisture absorption valley only appeared at 1900 nm. The intensity of spectral reflectance and the position of some characteristic absorption bands were different among different soil types. The spectral characteristics of different soil types developed from the same parent material were affected by the content of soil organic matter and the content of iron ion. Generally speaking, soil in Hainan is rich in iron but poor in organic matter. Iron contributed more to spectrum than organic matter. There were significant differences in spectral characteristics among laterite developed from different parent material. The spectral features of laterite developed from basalt was the most special,which had the minimum reflectivity and the faint moisture absorption valley only appeared near 1900 nm, therefore it was the soil type which was most easily to identify.Based on spectral clustering analysis for plantations laterite simple classification,the analysis of variance showed that there were extremely significant differences among different soil classifications P0.05. 【 Conclusion 】 Some certain regularities exist in the spectral reflectance curves of different soil types,and the spectral reflection characteristics change according to the soil parent material,the content of soil organic matter and the content of soil iron ions. So the soil spectral reflectance can be used as an indirect indicator of soil classification.