At Solegna, oil palm production potential is good, with a suitable climate (abundant, well distributed rainfall), deep, very clayey soils and a very good phytosanitary context (absence of the main pests and diseases known in Sumatra). The topography is undulating, with sometimes steep slopes. The network of collection paths needs to be improved as a priority. The delimitation of blocks and calculation of the areas planted need to be redone. Oil palms should no longer be planted in sloping zones or at the bottom of talwegs, and those already planted there that are not profitable should even be abandoned. The Marihat planting material contains a very high proportion of Dura (69%) whose exploitation is less profitable than that of Felda planting material, and which could be replaced before the end of the cycle. For upkeep and fertilization, preference should be given to Felda material over Marihat material, to young palms over old palms, and to zones with a gently to moderately undulating relief over steeply sloping zones. At Menthobi, the main point to note is the great natural wealth of the landscape in terms of flora and fauna. It is therefore essential to draw up a land use map, with the distribution of areas between oil palm blocks and natural conservation areas. The support of environmental experts will be sought for that purpose. In the higher zones (slightly to greatly undulating), the very clayey soil with hardpan at varying depths is not suitable for oil palm cultivation: the palms are exposed to a risk of strong water stress during the next long dry period (recurrent phenomenon in Borneo). The soil is much more suitable in valley bottom lowlands: rich in organic matter, sandy loam, permeable, no coarse elements. These zones have a good production potential, provided a drainage network is established with controlled flow downstream to drain off excess water in the wet season and hold back water in the dry season. There are plans to analyse 931 leaf samples in