基于FMT-AHP的海南农垦花岗岩类多雨区橡胶园地力评价

海南农垦是中国最大的天然橡胶生产基地,自第二次全国土壤普查以来橡胶园养分状况已发生了很大变化,但具体情况如何尚不清楚。运用耕地地力评价方法对海南农垦主要橡胶园的地力进行了系统评价,以期为橡胶园地力提升和天然橡胶的可持续发展提供理论支持。以土壤母质类型和降雨量为依据,首次将海南农垦橡胶园划分为8个类型区,并选取占海南农垦橡胶园总面积56.97%的花岗岩类多雨区作为评价区域,采集7204个0—20 cm层的土壤样品,运用特尔菲法、模糊数学理论和层次分析法确定11个评价指标及其权重,将评价区橡胶园地力划分为5等。研究结果发现:评价区以中间地力水平的二等、三等、四等橡胶园为主,占评价区橡胶园总面积的85.85%,它们广泛分布于琼中、屯昌、澄迈、儋州、万宁、保亭、乐东、三亚、陵水、定安、琼海、五指山、昌江、文昌和东方15个县市;一等地面积很小且分散,五等地相对集中面积也很小。相关分析表明土壤pH、有机质、有效磷和速效钾含量是影响评价区橡胶园地力水平的重要因素。评价区橡胶园土壤pH适宜橡胶树正常生长,但该区域土壤有机质和有效磷含量不能满足橡胶树正常生长的需要,而该区域一、二等地土壤速效钾含量能满足橡胶树正常生长,其三、四等地土壤速效钾含量仅达到橡胶树正常生长所需水平,随着地力下降到五等其土壤速效钾含量已不适宜橡胶树正常生长。根据上述研究结果,笔者建议橡胶园应大力间作绿肥,在增施有机质的基础上补氮、补钾、施用钙镁磷肥,同时加强养分管理,提高肥料利用率。

Soil productivity assessment of rubber plantations based on fuzzy mathematics theory and analytical hierarchy process in granite rainy areas of Hainan state farms, China

Hainan state farms are the largest production base of natural rubber in China. The nutrient status of rubber plantations has changed greatly since the second national soil survey that was published in 1982, but its specific conditions are not clear at present. Therefore, the soil productivity of the main rubber plantations in Hainan state farms was systematically evaluated by applying the evaluation methods of cultivated land productivity. The objective of this study was to provide theoretical support for the improvement of soil productivity of rubber plantations and sustainable development of natural rubber. For this study, the rubber plantations of Hainan state farms were split into eight different types on the basis of soil parent material and rainfall. The granite rainy area, which refers to the soil parent material for the granite and the average monthly rainfall for more than 100mm, accounted for 56.97% of the total area of rubber plantations in Hainan state farms and was therefore selected as a representative assessment area. A total of 7204 soil samples of the 0-20 cm tillage layer were collected from this area to evaluate soil productivity grades. We applied the Delphi method, the fuzzy mathematics theory and the analytical hierarchy process method. This would enable the determination of 11 assessment indexes and their weights based on the six principles of necessity, importance, diversity, stability, ease of access and simplicity. The soil productivity of the rubber plantations in the assessment area was then split into five grades. The results showed that the soil productivity of the assessment area was mainly in the second, third and fourth grades. This accounted for 85.85% of the total rubber plantation area in the granite rainy area, and was widely distributed in 15 cities or counties: Qiongzhong, Tunchang, Chengmai, Danzhou, Wanning, Baoting, Ledong, Sanya, Lingshui, Dingan, Qionghai, Wuzhishan, Changjiang, Wenchang and Dongfang. Soil that was assigned to the first productivity grade was found in a few, scattered places, whereas soil in the fifth productivity grade was not common but was found in a relatively concentrated area. Soil organic matter contents, soil pH and the concentrations of available phosphorus (P) and potassium (K) were found to be important impact factors affecting the soil fertility level of the rubber plantations. The soil pH was determined to be suitable for growing rubber trees in the assessment area. However, the content of soil organic matter and the concentration of available P were below the value suitable for growing rubber trees. The concentration of available K was suitable for growing rubber trees in the first and second productivity grade soils, only just reached the required level for rubber tree growth in the third and fourth productivity grade soils and was not suitable for normal growth of rubber trees in the fifth productivity grade soils of the assessment area. According to these results, it is suggested that green manure should be vigorously intercropped, and that fertilizing with N, K, Ca and Mg simultaneously with increasing organic fertilizer will strengthen the nutrition management and improve the utilization rate of fertilizer in rubber plantations.