Reclamation of acid soil in the south
|
| Most soil in the south is acid sulfate soil. Such soil comes from loam or clay piled up with saline soil sediment which consist of sulfuric compound. After being dried, it becomes acid sulfate soil. |
| Hoe to observe acid soil area in the South |
|
(1)
|
Rice production is not more than 20 liters/rai. |
|
(2)
|
In acid soil plain area where rice is grown, there is no tillering. When uproot the rice, its root is black. In some area, rice is withered after transplanting and rice production decreases. |
|
(3)
|
Water in the area is clear like being swung by alum. Its taste is acid or sour. |
|
(4)
|
There are plants like grass, reed and Eugenia growing in acid soil area. |
|
(5)
|
Dig the soil about 50-100 cm. and find sulfuric dust or yellow substance spread in soil texture |
|
| Area where acid soil is found |
| In the South, acid soil is found in the lowland or the lowland among sandy bar.Now, such area is the paddy-field or the farm. Some area is left and covered with grass, reedand Eugenia. |
| Important problem |
| Acid sulfate soil causes iron, aluminum and manganese melt and do harm to plants. Phosphorus could not be applies by plants. As a result, an amount of crops yield decreases. |
| How to reclaim plantation |
| plantation could be reclaimed in order to plant crops and vegetables. plot preparation to prevent acidity of the soil is as the following: |
|
(1)
|
prepare a plot with 6-8 m. width depending on the kinds of plants. The furrow is wide 1.0-1.5 m. |
|
(2)
|
Dig soil surface of the furrow and pile it up at the center of the plot. |
|
(3)
|
Dig the bottom soil with 50 cm. depth and pile it up at the edge of the plot. |
|
(4)
|
Prepare the plot for planting. |
|
(5)
|
Build a dike around the plot in order to prevent the flood. Prepare water control and drainage by using pump or natural drainage. After preparing plantation, improve the soil with soil amendments like dolomitic limestone or slaked lime 1.5-2.0 ton/rai including irrigation and maintenance of water level in the furrow to prevent acidity of the soil. |
|
| Three ways to decrease acidity of the soil |
|
(1)
|
Leach acidity from the soil with water. A large amount of water is used to control water level in the furrow. When such water becomes acid sulfate, drain it. |
|
(2)
|
Scatter soil amendments like slaked lime and wallow the soil surface. |
|
(3)
|
Apply both of two ways above. |
|
| |
| Plant management |
| Consider problems and solution for the landuse. Avoid planting in case of having factors risky for failure of crops. For the area where the irrigation and the drainage is prepared and soil amendments are cheap and available, select plants suitable for acid soil and in demand. |
| |
| Soil management and chemical fertilizer application to plants |
|
Type
|
Management
|
|
Rice
|
Varieties of rice for growing are KDML , RD13, Morearun, Lookdang, Lookleung, Nanguaonoi, Tammahai, Chornangeung. Apply dolomitic limestone 1.5-2.0 ton/rai. In irrigated area, drain water 4-5 times. Add chemical fertilizer (16-20-0 or 16-16-16) 25-40 kg./rai befor transplanting and add Uria 5-10 kg./rai when its panicle appears. |
|
Sweet Corn
|
Drop corn seeds 3 seeds/hole. The plot is 25x25 cm. Apply Furada 4 kg./rai and add chemical fertilizer (10-10-10-10) 50-100 kg./rai by dividing it into 2 parts.Add the first part at the bottom of the hole and add the second part 25 days after planting. When sweet corn grows up, add Uria 10 kg./rai |
|
Mango
|
The plot is 8x9 m. Dig the hole 50x50x50 cm. and add chemical fertilizer (15-15-15) 1-2 kg./plant by dividing it to add 2 times when its age is less than 4 years. When its age is more than 4 years, add chemical fertilizer 2-4 kg./plant. |
|
Coconut
|
The plot is 8x9 m. Dig the hole 50x50x50 cm. and add chemical fertilizer (15-15-15) 1-2 kg./plant by dividing it to add 2 times when its age is less than 4 years. When its age is more than 4 years. add chemical fertilizer (13-13-21) 2-3 kg./plant |
|
Pomelo
|
The plot is 8x9 m. Dig the hole 50x50x50 cm. and add chemical fertilizer (15-15-15) 1-2, 2-4 and 5 kg./plant by dividing it to add 2 times when its age is 2, 2-4 and more than 4 years respectively |
|
Tangerine
|
The plot is 3x9 m. Dig the hole 50x50x50 cm. and add chemical fertilizer (15-15-15) 1-2 and 2-4 kg./plant by dividing it to add 2 times when its age is less than 5 years and more than 5 years. |
|
|
|
|
| Acid soil area could be dig as a pond to keep aquatic animals like a carp of the genus Puntius, a snakehead mullet. Drain the water in the pond and scatter dolomitic limestone at the rim and the bottom of the pond to prevent acidity of soil. |
| |
| |
