The Model of Relationship Eucalyptus pellita Production with Land Characteristics as Formulation Basic Land Suitability Criteria

Abstract

Eucalyptus pellita is a fast growing plant that has great potential in the development of industrial timber estates. There persists notion, that the spesies is capable growth in degraded land and minimum silviculture input, as a result forestry plantation in some areas obtain the low productivity. On the other hand, some research suggested that E. pellita responses on soil characteristics and nutrient input. The objective of this study was to create the relationship model of the land characteristics with plant production of E. pellita, determine the contribution of land characteristics to plant production classes of E. pellita, and establish the criteria of land suitability for E. pellita associated with the plant production. The method in this research was exploration survey. This study used secondary and primary data. Collection of secondary data derived from the 5 districts namely Rasau Kuning, Sorek, Malako, Nilo, and Duri I, while the primary data collection was done at the Gelombang, Rasau Kuning, Tapung, and Duri II district at PT. Arara Abadi, Riau. Types of secondary and primary data were collected such as land characteristics and plant productivity. Secondary data were used for the formulation of the relationship model between land characteristics and plant production, and the formulation of land suitability criteria for E. pellita, while the primary data were used for the validation test. The data were analyzed with stepwise regression, discriminant analysis, and boundary line method. SPSS software version 17.0 was used for statistical analysis. Then, validation test for assessing of land suitability criteria based production classes. The results of multiple linear regression analysis with stepwise method showed that land characteristics were significantly to the E. pellita productivity with negative correlation namely exchangeable K, Mg, Al, total P, and slope, while base saturation, total N, and clay content were significantly with positive correlation. Based on discriminant analysis, land characteristics that high contributed to plant production classes were exchangeable K, Al, and Mg, and cation exchange capacity (CEC). The optimum land characteristics to support maximum productivity of E. pellita were sandy clay loam, sandy clay, or loamy sand soil texture, pH 4.0 - 4.7, base saturation > 7.51%, organic C > 1.10%, Al saturation < 37%, total N > 0.08%, available P > 4.7 ppm, exchangeable K > 0.03 cmol (+) kg-1, and a slope < 18%. Then, the criteria were validation on the field and suggested that the land suitability criteria about 70% valid correctly. This means that as many as 70% of all samples were tested based on the land suitability criteria of valid with the expected production levels.