**2. Principle of oil palm plantation sustainability (OPPS) evaluation**

There are at least three principles that can be used as guidelines for assessing OPP in Indonesia. First, the evaluation of the oil palm industry effect, especially OPP, on S-L-E should not be generalized, but evaluated objectively and proportionally, particularly based on the origin of the OPP. In reality, OPP in Indonesia is very diverse, both from the type of land, climate, topography, age and plantation management, as well as the origin of the OPP. OPP in Indonesia is scattered on mineral and peat soils with very varied characteristics, with very varied slopes and climates, etc. Not all OPP comes from forest clearing, many also come from the conversion of rubber, cocoa or other plantation crops, moor or grassland, mixed gardens and even rice fields, shrubs, *Imperata cylindrica* grass fields, idle or abandoned land, former illegal logging, critical land, etc. OPP management differences also have different effects on S-L-E conditions. Thus, data on the origin of an OPP is important and crucial to be traced and identified.

Second, OPP in Indonesia is mostly planted on suboptimal land. Suboptimal land has marginal land quality [6–9]. Facts in the field show that oil palm plants are able to adapt and be cultivated on suboptimal land. In fact, the OPP was deemed able to apply regional ecological principles based on the optimization and preservation of resources, especially on suboptimal land. In other words, OPP is not always associated with a decrease in soil quality, land quality and environmental quality. In fact, in some places, OPP planted on marginal lands is believed to be able to improve soil quality, land quality and environmental quality.

Third, to resolve disagreements and polemics about OPP in Indonesia, an objective evaluation system is needed as a platform or indicator that can assess OPP in an empirical, measurable, quantitative, accurate and standardized manner. The

*Necessity, Principle and Technique of Evaluation Model to Assess Sustainability of Oil Palm… DOI: http://dx.doi.org/10.5772/intechopen.98585*

reliable evaluation model system is also expected to be able to evaluate and provide information about the quality of S-L-E; palm oil productivity; constraining factors for the growth and production of oil palm; as well as directions for management recommendations to increase the productivity and quality of S-L-E and prevent land damage and degradation. The evaluation system needs to be supported by the Plant Potential Productivity Index (PPPI), Soil Quality Index (SQI), Land Quality Index (LQI) and Environmental Quality Index (EQI).
