References
- Bingham, F. T. (1962). Chemical soil test for available phosphorus. Soil Sci., 94, 87–95.
- Chemistry Division, E.A.A.F.R.O., Muguga (1967). Methods for the analysis of soils.
- Friend, M. T., and Birch, H. F. (1960). Phosphate responses in relation to soil tests and organic phosphorus. J. Agric. Sci., 64, 341–347.
- Humpries, E. C. (1956). Mineral component and ash analysis. Modern methods of plant analysis. Springer-Verlag, Berlin. Vol. I, 468–509.
- Jackson, M. L. (1958). Soil Chemical Analysis. Prentice-Hall Inc., Englewood Cliffs, N.J. 326–338.
- Jenny, H., Vlamis, J., and Martin, W. E. (1950). Greenhouse assay of California soils. Hilgardia, 20, 1–8.
- McIntosh, J. L. (1964). Vermont soil test. Department of Agronomy, University of Vermont (Cycl. Rept.).
- Mehlich, A., Pinkerton, A., Robertson, W., and Kempton, R. (1962). Mass analysis method for soil fertility evaluation. Dept. Agric., Kenya. (Cycl. Rept.).
- Olsen, R. S., and Dean, L. A. (1965). Methods of soil analysis. Chemical and microbiological properties. Agronomy series No. 9, Pub. by Am. Soc. Agron. Madison, Wise., U.S.A., 2, 1035–1049.
- Robinson, J. B. D. (1968). Advisory soil or plant analysis and fertilizer use. II—Evaluation of soil analysis methods with maize yield data. E. Afr. agric, for. J., 34, 140–152.
- Robinson, J. B. D., and Semb, G. (1968). Advisory soil or plant analysis and fertilizer use. I—Comparison of soil analysis methods. E. Afr. agric, for. J., 34, 117–127.
- Smith, J. A. (1968). Personal communication. Ontario Agricultural College, Guelph, Canada.
- Williams, E. G. (1962). Chemical soil tests as an aid to increased productivity. Trans. Joint Comm. IV-V, I.S.S.S. (New Zealand) 820–834.
- Williams, R. J. B., and Cooke, G. W. (1965). Measuring soluble phosphorus in soils, comparison of methods and interpretation of results. Soil and Fertilizers, 29, 343.