Land Use Changes Affecting Soil Organic Matter Accumulation in Topsoil and Subsoil in Northeast Thailand
Table 1
Characteristics and agronomic management of studied plots of different land use systems at various locations.
Study location
Land use type
Sampling area (ha)
Altitude (masl)/1
Agricultural practices
Muang
Forest
6
192
/2Secondary dry dipterocarp forest.
Cassava
3
193
/3Cassava (Kasetsart50 or KU50 variety) was cultivated yearly in the early rainy season (May to June). Nitrogen fertilizer, urea (46–0–0), was applied to the crop at the rate of 113 kg·ha−1 at planting and fertilizer formula 15–15–15 of N–P2O5–K2O at the rate of 313 kg·ha−1 was applied three months after planting (MAP). The crop was harvested from March to May of the following year.
Sugarcane
3
198
/4Sugarcane KK3 variety was cultivated yearly in the late rainy season from October to February. Fertilizer formula 15–15–15 of N–P2O5–K2O was added to the crop in two split applications at planting and 4 to 6 MAP. Cattle manure was also added in some years.
Paddy
5
174
/5Glutinous rice (RD6 variety) and nonglutinous rice (KDML 105 variety) were cultivated yearly by transplanting seedlings in June. Urea (46–0–0) was applied to the crop at the rate of 150–180 kg·ha−1 at planting and fertilizer formula 16–16–8 of N–P2O5–K2O was applied at the rate of 125–156 kg·ha−1 at the tillering stage. The crop was harvested during November to December.
Kantharawichai
Forest
6
157
/2
Cassava
3
159
/3
Sugarcane
3
154
/4Cattle manure was added in every single year before sugarcane plantation.
Paddy
5
156
/5
Kosum Phisai
Forest
6
190
/2
Cassava
3
190
/3
Sugarcane
3
189
/4
Paddy
5
182
/5
Kut Rang
Forest
6
203
/2
Cassava
3
198
/3
Sugarcane
3
195
/4
Paddy
5
198
/5
Borabue
Forest
6
185
/2
Cassava
3
181
/3
Sugarcane
3
186
/4Cattle manure was added in some years.
Paddy
5
174
/5
Wapi Pathum
Forest
6
185
/2
Cassava
3
186
/3Green and cattle manures were applied before cassava planting in some years.
