Potensi Sumberdaya Lahan Pulau Sulawesi Mendukung Peningkatan Produksi Padi, Jagung, Dan Kedele

. The reconnaissance soil survey and mapping programme at scale of 1: 250,000 in Indonesia has been successfully completed, marked by publication of the soil maps in 2012 for each province in Kalimantan, Sulawesi, Maluku, Nusa Tenggara, Java, and West Papua. From the soil map legends, it can be obtained the information of climate condition, landform, relief an slopes, type and properties of soils that affect land resource potential for agricultural development purpose. The island of Sulawesi (18.7 million ha) has variation of climate condition from wet to dry, which is reflected by udic, ustic and aquic soil moisture regimes. The main landform groups, from the most extensive respectively consists of Tectonic (37.63%), Volcanic (37.39%), Alluvial (11.82%), Karst (8.31%), Marine (2.65%), Fluvio-Marine (0.41%), and Peatland (0.13%). The relief varies from flat to mountainous, with composition of flat to nearly flat (15.85%), undulating (4.86%), rolling (6.50%), hillocks (11.96%), hilly (19.30%), and mountainous (39.85%). The soil parent materials are vary, which composed of organic and alluvium deposits, acid to basic sedimentary rocks, young and old volcanic rocks, acid to basic intrusive rocks, and metamorphic rocks. Nine soil orders were formed from these parent materials, namely from the most extensive respectively Inceptisols (58.15%), Alfisols (10.44%), Ultisols (10.25%), Mollisols (6.21%), Entisols (5.54%), Oxisols (4.87%), Andisols (2.18%), Histosols (0.41%) and Vertisols (0.28%). Based on the biophysical data, there are large potential lands in Sulawesi, consisting of wetland soils with slope of <3% covers about 2.30 million ha for ricefield (sawah), and dryland soils with slopes of 3-15% covers about 1.98 million ha for maize and soybean development. Actually, the most of land potential have been cultivated for various agricultural crops. Therefore, the increasing production of paddy rice, maize and soybean have more opportunity to optimalize or intensify the use of existing agricultural land rather than to land extensification. By assumption, if 50% of the potential wetland is cultivated with paddy twice a year with mean productivity of 4,71 t ha-1, then it would get about 10.82 Mt GKG (dry unhulled rice). And also, if 50% of the potential dryland soils is cultivated with maize and soybean at least one time a year with mean productivity of 4,05 t ha-1 and 1,34 t ha-1 respectively, then it would get about 4.02 Mt dry grain corn, and 1.33 Mt dry grain soybean. Compared to the existing production of the three food crops according to BPS in 2012 (paddy 7.82, maize 2.94, and soybean 0.05 Mt), there are very significant increasing production for paddy, maize and soybean as much as 38.4%, 36.7%, and 2461.5% respectively