4. Group of soil Series No.4

This group includes mostly somewhat - poorly drained, fine textured ( silty clay loam to silty clay ) soils which occur exclusively on flood plain or alluvial plain. They are moderate fertility and soil reaction is neutral to slightly alkaline. Soils in this group are Bang Mun Nak (Ban), Bang Pa -in (Bin), Chai Nat (Cn), Pimai (Pm), Ratchburi (Rb), Saraburi (Sb), Sing Buri (Sin), Sri Song Kram (Ss), Tha Pon (Tn) and Tha Rua (Tr) series.                Paddy rice have been cultivated in most of areas. Drainage is recommended if they are used to produce sugar cane, truck crops and fruit trees.

Problems : Soil texture is massive and cracking when dry which is difficult to be prepared. Water is logging in rainy season. In some places saline can be found in the sub-soils.

Management for rice : Prepare and mix crop residue into moist soils and leave for 3-4 weeks. If managing by green manure, it should be the mixture of 4-6 Kg/rai of 50-70 days Sesbania rostrata and 16-20-0 chemical fertilizer or LDD liquid organic fertilizer in the soils and leave for 1-2 weeks. Top dressing again with 16-20-2-0, 35-40 days after transplanting. Farm ponds are recommended to preserve water to be used in dry season or second rice crop or short season upland crops after first rice.

Management for vegetable or orchard : Raised bed to 6-8 meters wide with 1.0-1.5 meters drainage canal. Apply 2-3 ton/rai compose fertilizer or animal manure with chemical fertilizer or LDD liquid organic fertilizer. Apply 20-35 kg of compose or animal manure into 50*50*50 meters pit to grow orchard. Apply compose fertilizer or animal manure with chemical fertilizer or LDD liquid organic fertilizer at vegetative growth, before and after harvesting. Farm ponds and water management are recommended to preserve water to be used in dry season.