20. Group of Soil Series No.20

This group of soils consists of somewhat poorly drained, coarse-textured soils that are salt affected and occupy on low-lying terrain of the north-east plateau and coastal plain. Most of the areas are paddy rice but yield is relatively variable due to degree of salinity. Soils in this group are Kula Ronghai (Ki), Nong Kae (Nk), Tung Sumrit (Tsr) and Udorn (Ud) series.

Problems : Saline soils with hard pan in saline accumulated layer, low fertility, lack of fresh water in strong saline areas, especially in dry season, water logging in rainy season.

Management for rice : Logging water in the field to leach salt from the soils,. Before applying salt tolerated 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 Sesbinia rostrata or S. speciosa and 15-15-15 chemical fertilizer or LDD liquid organic fertilizer. Top dressing of 35-45 days after transplanting rice (using 30-35 days, 5-8 rice seedling per hole) of 20*20 cm. spacing. 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 : Salt tolerated vegetable or orchard would be planted in less salted affected areas and close to irrigated water. Raised bed to 6-8 meters wide with 1.0-1.5 meters drainage canal. Raised bed around the areas then apply 3-4 ton/rai compose fertilizer or animal manure with chemical fertilizer or LDD liquid organic fertilizer. Apply 25-50 kg of compose fertilizer or animal manure into 50*50*50 meters pit to grow orchard. Mixed gypsum with soils from the pit then leach with water and mulch the soils to prevent up rise salt. 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.