RESEARCH AT MASSEY

New Zealand Herald, Volume LXXV, Issue 23002, 1 April 1938, Page 15

RESEARCH AT MASSEY

PASTURE ESTABLISHMENT EARLY TREATMENT NEEDED BY H.B.T. From time to time the writer has stressed the importance when laying down new pastures of allowing the grass plants to make full growth to maturity before heavily grazing them. The reasons advanced in favour of this abstention from using "the early fresh bite from newiy-established pasture" were that root growth is roughly proportionate to leaf or foliage growth, a balance being generally maintained both in different species, and between plants of the same species. The leaves act both as the stomach and lungs of the plant, digesting the raw food sent up by the roots, and incorporating with it the carbon extracted from the sir by the stomata. Also they extract matter from sunlight which we see incorporated in the plant as chlorophyll, the green colouring matter of plants If the leaf growth of young, developing plants is continuously kept short, it must be obvious that they cannot deal efficiently with the food sent up by the roots, nor can they fully do their even more important work of extracting food from the air which, after incorporation with the other foods and moisture as sap, is pumped down to stimulate root growth. Permanency in pasture grasses therefore depends primarily upon the Unrestricted early leaf growth of the plants, which promotes deep rooting. From observation of the longevity, or permanence, of pastures allowed to mature before grazing, compared with those kept grazed closely as soon as there was a bite for stock, the writer came to the conclusion that early grazing seriously and permanently reduced root growth. This conclusion has now been graphically supported by research done by W. A. Jacques, of Massey Agricultural College. "It is very patent," says Mr. Jacques in his bulletin on this subject, "that root and shoot growth are so interrelated that interference with the functions of one will be correspondingly reflected in the activities of the other. "Although the trial extended over a period of only three months and a-balf, it is considered that the data obtained are applicable to swards that have been established for a considerable time. The most important result recorded here is the early inhibiting effect of defoliation on root development, and the failure of overgrazed plants to develop adequate 1 root systems," nays Mr. Jacques.