1. Department of Soil Science, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
2. African Plant Nutrition Institute, Benguérir, Morocco
3. International Plant Nutrition Institute, South Asia Program, Samastipur, Bihar, India
4. Department of Agronomy, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
5. Asia, Africa and Middle East Program, International Plant Nutrition Institute, Peachtree Corners, GA, USA