 |
| Management
of acid soils
by using rock phosphate and chemical fertilizer for cassava on Warin soil series |
| Methin
Siriwongse Nongkran Maneewan and Charoen Charoenchamratcheep |
| ABSTRACT |
| Research
of rock phosphate and chemical fertilizer on Warin soil series under
cassava cultivation was studied at Ban Non-Khaow, Suanmon sub-district,
Manja-Kiri district , Khon Khan province during 1995-1998. The objectives
of this study were to examine the effects of rock phosphate and chemical
fertilizers on change of chemical properties of soil and growth and
yield of cassava. It consisted of 7 treatments and the plots were
arranged according to a completely randomized block design with 4
replications. The results indicated that rock phosphate had the effect
on neutralizing soil acidity, especially at the rate of 400 kg/rai
and the soil pH could be raised over 5.5 through 3 years. Moreover,
rock phosphate could supply at the range of moderately high and high
available phosphorus in soil solution and supply exchangeable calcium
in soil but inadequate for plant. However, rock phosphate gave no
effect on yield of cassava significantly. It could be suggested that
in this soil, restriction were found not only available phosphorus
but also exchangeable calcium and magnesium had severe restricted too. |
| Keywords : acid soils, rock phosphate , Warin soil series , cassava |