Response of berseem (trifolium alexandrinum) shaftal (trifolium resupinatum) and lucerne (medicago sativa) to phosphorus application for yield, nodulation and nitrogen fixation

Abstract

In a pot culture experiment, increasing levels of phosphorus at 40, 60, 80, 100 Kg P/sub 2/O/sub 5/ ha/sup -1/ in the presence of uniform dressing of nitrogen and potash (K/sub 2/O) each applied at 10 and 40 kg ha-1 increased significantly the nodulation response number and weight of nodules plant/sup -1/, nitrogenase activity, n-uptake and dry mater yield of shoots and roots of berseem, shaflt and lucerne. The increase in shoots n-uptake was in the range of 117 to 233 percent for berseem, 52 to 224 percent for shaftal, 50 to 330 percent for lucerne: whereas the increase in the root n-uptake was in the range of 67 to 266 percent for berseem, 64 to 240 percent for shaftal and 23 to 114 percent for lucerne. The improvement in the n-uptake of shoots ad roots in obviously due to marked improvement in nodulation response number and weight of nodules plant-1) and nitrogen activity of the test crops as a result of all the applied doses of phosphorus. (author)