Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute, New Delhi, 110012.
* Present address: Indian Institute of Soil Science, Z-6, Zone-I, M.P. Nagar, Bhopal, Madhya Pradesh, 462011.
Possibility of rock phosphate-pyrites as a source of P to a fodder legume, berseem (Trifolium alexandrinum) was investigated in a pot culture experiment. Effect of rock phosphate treatments on dry matter yield was significant in the second and third cuttings of berseem. Jhabua and Mussoorie rock phosphates recorded, by and large, higher yield than the other two sources in the second cutting, whereas Maton and Mussoorie rock phosphates were superior to the other two in the third cuttings. Similar beneficial effect was observed for P uptake by the crop in the second and third cutting. These two sources of P also increased the residual available P (Olsen's P). The wider the ratio of P:S in the rock phosphate-pyrite mixtures, the higher was the residual P status of the soil. The 1:4 ratio of the mixtures also produced the lowest dry matter and P uptake by the crop. Water soluble phosphate treatmrnts proved far more superior to all rock phosphate treatments in all these respects.
Rock phosphate, pyrites, mixtures of rock phosphate and pyrites, berseem, dry matter, yield, P uptake
