Some effects of clipping the tops upon the root development of lucerne (Medicago sativa L.)

Abstract

V. Summary and abstract1. Inoculated lucerne was grown in pots of sand and watered with nitrogen-free food solution. In some of the pots the lucerne was clipped once, in some twice and in some it was left unclipped. Pots were harvested on four dates at intervals of about three weeks. Counts and measurements of nodules were made and dry weights and nitrogen contents of tops and roots were obtained.2. Clipping did not significantly alter the nodule numbers, their mean size, or the total nitrogen contents of the plants, i.e. in tops, including clippings, plus roots.3. Clipping, however, resulted in a decrease in the nitrogen content of the roots of about 40 per cent, as compared with undipped plants. This nitrogen was transferred to the tops where it was removed in the clippings.