4. Date, N. 1989. Soil amendment materials. In Handbook of Fertilizers. 4th ed., Pub. Assoc. of Agriculture and Fisheries Culture. Tokyo., Japan 295-314.*
5. Datloff, A. 1970. The effect of some fungicides on root nodule bacteria and subsequent nodulation. Aust. J. Exp. Agric. Anim. Husb. 10 : 562-567.