39. Group of Soil Series No.39

This group of soils is well drained, deep, coarse textured that developed from transported material derived from coarse-grained parent rocks. They occupy on uplands of erosional surface and alluvial fans in high precipitation areas . Soil fertility is low whereas the soil reaction is strong acid. Soils in this group are Ko Hong (Kh), Na Tawi (Nat), Sa Dao (Sd) and Tung Wa (Tg) series.                Majority of the land uses are tree crops i.e. rambutan, durian, mangosteen, coconut, parabubber and oil palm.

Problems : Flood damage by over land flow, sandy soils, lack of water in dry season.

Management for upland crops or vegetables : This group of soils needs crop rotation and soil improvement with 2-3 ton/rai compose fertilizer or animal manure or mixed green manure (broadcast 8-10 kg/rai sword bean , 6-8 kg/rai cow pea or 4-6 kg/rai Crotalaria juncia) with soils before flowering. Chemical or liquid LDD fertilizer will also be applied according to recommendation . Plants should be grown on the contour or strip cropping with mulching. Soil should be conserved by vetiver around the areas. Farm ponds are recommended to preserve water to be used in dry season.

Management for orchard : Soil preparation in 50*50*50 pit is to mix 20-35 kg compose fertilizer or animal manure. Conserve the soils by cover crops, mulching, and contour or fencing the tree with vetiver. Application of compose fertilizer or animal manure with chemical or liquid LDD fertilizer at vegetative growth, before and after harvesting. Farm ponds are recommended to preserve water to be used in dry season.