 |
| Study
on rates of rock phosphate on acid sulfate soil for sweet corn-mungbean cropping system |
| Rosmalin
Na ranong Kamchai Kanchanatanaset Udom Arunakun Sutthipong Pradabvit and Charoen Charoenchamratcheep |
| ABSTRACT
|
| Rates of rock phosphate on acid sulfate soils (Rangsit soil series - very acid phase) for sweet corn-mungbean cropping system was studied by raise bedding. The objective were to find out the suitable rates and also the residue effect of rock phosphate on mungbean. This experiment was studied at Nakorn Nayok Land Development station during 1992 - 1994. The experiment was designed in RCBD with 5 treatments; rock phosphate - RP (4% avail. P2O5) at 0 100 200 300 and 400 kg/rai (applying every year before corn crops). For mungbean, only nitrogen was applied. |
| For three year, the results showed that rates of RP 100 kg/rai can increase corn yield every year, however rates of RP 300 kg/rai gave the highest yield. Comparing the net profit for 3 years, it was found that appling RP 100 kg/rai gave the net profit (2,077 bath/rai) and RP 300 kg/rai gave 2,581 bath/rai. |
| Considering the residue effect of RP, it was found that the yield of mungbean was very low and alsothe net profit was net suitable for the capital. |
| After improvement, some chemical properties of soil were spparently changed. It was found that soil acidity and aluminum were decreased; in the contrary, calcium increase. |
| Keyword : rock phosphate, acid sulfate soils, corn, mungbean, cropping system |