1. M. Afzal:
Soil Science Department, NWFP Agricultural University, Peshawar, Pakistan
2. Muqqadar Khan:
Soil Science Department, NWFP Agricultural University, Peshawar, Pakistan
3. A. U. Bhatti:
Soil Science Department, NWFP Agricultural University, Peshawar, Pakistan
4. J. K. Khattak:
Soil Science Department, NWFP Agricultural University, Peshawar, Pakistan