Various methods of root sampling are reviewed and discussed in relation to the type of information required. The root sampling techniques at the Grassland Research Institute are described and examples of sampling errors are given. Details of a root washing machine are given.
Swards based on a mixture of SI 70 tall fescue and S215 meadow fescue were very early in spring, gave high yields for conservation in mid-season and, rested from mid-August, gave good grazing in November-December. Under this treatment, the tall fescue assumed dominance, and the swards were persistent and remained productive. The digestibility of the tall fescue swards was always higher than that of swards based on cocksfoot with which they were compared. During spring and autumn the former sward was better grazed by stock, but the position was reversed in mid-summer. Cattle grazing tall-fescuedominant swards made better liveweight gains than those grazing cocksfoot swards during November-December.
The effects of management on the production of winter grass wen studied of 47 site England and Wales from 1954 to 1958.
Cocksfoot swards provided better grazing during December and January than perennial ryegrass. The best treatment for winter‐grass production from cockfoot swards was to rest from mid‐August, giving un application of 52 lb of nitrogen per acre at this time.
Perennial ryegrass produced relatively high yields if rested from early September, but the herbage should be grazed before the end of November because of the risk of it rotting.
Cocksfoot herbage in normal swards lost more weight from December to January than cocksfoot sown in wide drills.
Local Factors, such as aspect, altitude and sward vigour, were generally more important than latitude in determining level of yield in December. but there were greater lovsess of dry matter from December to January in the north than in the south.
Herbage, stuhble and root weights vv-ere recorded for thirteen months on various leys subjected to two treatments differing in frequency of cutting.The root-weight per unit area of a ryegrass/white-clover ley was not affected by the Frequency of cutting, but the less frequently cut plots had fewer tillers per unit area; the root-and stubble-weight per tiller was, therefore, higher on the less frequently cut plots, On a cocksfoot ley ihe root-weight was not affected by the cutting treatment, but in late summer and early autumn the stubble-weight was considerably higher on the less frequently cut plots.When cocksfoot was grown in rows 2 feet apart, the more frequent cutting decreased bolh the root-and stubble-weighl.On grass leys root-weights were heaviest in the summer and thereafter decreased until the following spring.The root-weight of lucerne decreased from May to July, increased to a maximum in December and then decreased in weight. The changes in root-weight under lucerne leys were mainly due to changes in the weight of the tap-roots.The vertical distribution of roots was recorded, and, in the case of the cocksfoot in rows, the lateral distribution of roots is also given.
The influence of defoliation on the root, stubble and herbage weights of perennial ryegrass during establishment was studied on spaced plants in the greenhouse and field.In the greenhouse trial the rate of root elongation was reduced by a single defoliation. In both the field and greenhouse, cutting reduced the number of roots and tillers per plant but increased the number of roots per tiller. A few weeks after defoliating plants in the field there was a lower root weight on the cut plants than on the uncut. Eventually the influence of a single cut disappeared, but if the cutting was in the laie summer or autumn the plants commenced the winter with a smaller amount of root and stubble, and this appeared to have a deleterious effect on the earliest spring growth.Herbage growth in March and April was positively correlated with both root and stubble weights in the previous November.As the number of cuts dtiring the establishment period (March-November) was increased from 0-4 the root and stubble weight per plant progressively decreased.The root and stubble weights decreased during the winter.
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