NITROGEN FOR GRASSLAND.

Southland Times, Issue 19223, 19 April 1924, Page 10

NITROGEN FOR GRASSLAND.

RESULTS OF EXPERIMENTS AND COMPARISONS. It has been frequently maintained that the addition of nitrogenous manures tc grassland, more particularly to pasture, if unnecessary. Phosphates, usually as basic slag, and in some instances with the addition of potash salts, have been considered sufficient to encourage clovers and other leguminous plants, thus enabling the latter to obtain nitrogen in sufficient quantitifes from the air to supply the needs of the grasses. Although as a general rule this method of manuring is perfectly satisfactory, instances frequently arise where the direct action of nitrogenous manures has produced remarkably good results. It frequently happens when land is laid down to grass, especially in unfavourable seasons, that the growth is at first extremely unsatisfactory. One field in particular has been under observation during the past two seasons, in which, either through poverty of the soil or through the use of a poor seeos mixture, the herbage has remained exceedingly poor. The soil was somewhat heavy, a strong silty loam, and lying in a hollow it was poorly drained. The field was chosen for a series of experiments to compare the action of various phosphates with and without potash and nitrogen on this type of soil, although the manures with the exception of nitrogen were applied in the winter of 1922, very little benefit could be observed from the application of either slag or superphosphate alone and in conjunction with sulphate of potash during the past summer. EFFECT OF NITROGEN. In spring, however, equivalent weights of nitrate of soda and sulphate of ammonia were applied on duplicate plots over the field at the rate of Jcwt sulphate of ammonia per acre. Within a few weeks of this application the plots receiving nitrogen were conspicuously better than any of the others. • Very little difference could be observed for some time between the action of nitrate of soda and sulphate of ammouia, but later observations have revealed a slightly superior effect on the plots receiving nitrate of soda. The effect of phosphates, even with the addition of sulphate of potash, has been only slightly to increase the amount of herbage. An e.-ceedingly small amount of clover was present on the field in the first instance, and the phosphates had only been able to encourage their growth to a slight extent On the plots receiving nitrate of soda, however, clovers were well developed; the grasses also were in a more flourishing condition, and the poor patches, so prominent on the plots, had almost disappeared. So far as one season's observations go, it would appear that although both sulphate of ammonia and nitrate of soda have encouraged the grass giving a better bottom growth to the field, nitrate of soda has at the same time encouraged the growth of clover to a remarkable extent, whilst, as might have been expected, sulphate of ammonia was not so beneficial to this plant. The field was grazed throughout the season, but whilst the remainder of the plots were only roughly grazed, those receiving nitrogen were always grazed exceedingly finely. REMARKABLE DEVELOPMENT. On another field, on light sandy soil—but in this instance where the pasture had been established for a great number of years—the effect of nitrogen was not so conspicuous except that the growth of clover was clearly encouraged by the addition of the same light dressing of nitrate of soda. Several observers of these plots have been impressed by the extraordinary results obtained with nitrogenous manures, agreei g that on the first field these plots certainly appear to be a full year in advance of the unmanured portion It would appear, therefore, that, in certain instances grassland can b*. so poor that phosphatic manures alone are not sufficient to insure a rapid growth of grass and clover under unfavourable conditions, and that, a light dressing cf a quick-acting nitrogenous manure, preferably nitrate, of soda, would provide sufficient stimulus to obtain full benefit from subsequent dressings of phosphates and potash. Examination of the root system of the several plots tends to explain the remarkable development, of herbage, the roots on the nitrogen plots being far more strongly developed and more numerous than on the plots receiving phosphates and potash alone. GREAT Output of butter. OVER 870 LBS IN 12 MONTHS.

The remarkable output of 871.391 b. of butter-fat in J2 months, is the achievement of a Jersey cow owned by Mr D. Watkin, of Takanini in the Auckland district. Mr Watkin has just received a cheque for £3l 10s from the New Zealand Jersey Association as a subsidy payment earned by this cow. He has also been awarded an Association medal on account of the phenomenal production of the Jersey. ROTTED MANURES.

Rotted manure is apt to be a substance of rather uncertain composition so far as fertility elements are concerned. Theoretically, rotted manure should be more valuable, pound for pound, for plant uses than fresh manure in that the plant food it contains is more available for assimilation. It should contain, as a rule, a larger percentage of fertility elements than waste which is newly produced. Both of these statements, however, are apt to be misleading in that neither of them takes any account of the losses involved in the manure in question. The gain, so far as fertility elements is concerned, is apt to be more apparent than real. The conditions prevailing during the rotting process have much to do with the real value of the resulting product. If the decomposition has gone on in the open where the waste has been freely exposed both to sun and rain, no man can say—short of actual analysis —how much plant food remains after leaching and bacterial fermentation have demanded their toll. It may be fairly considerable or it may be little enough! If, on * the other hand, the manure has been stored in a pit of tight construction and has remained there long enough for disintegration to take place the loss will be limited in all probability to the escape of a portion of the nitrogen in the form of ammonia, due to bacterial action or heating. However, manure rarely stays in a pit long enough to undergo decomposition as it does in a neglected pile or undergrounds The physical results which accrue from rotting are. likely to be more ' uniform than are those that are purely : chemical. The manure becomes of similar j character throughout. The coarse litter is ] disintegrated and more intimate jnixing 1 with the soil is possible when the waste is ; applied. And furthermore, there is less actual material to be handled because, in the process of rotting, manure naturally loses weight. However, the best place for manure to rot is underground. In this case nothing can be lost. Mother Earth takes care of all the products of decay and transforms them into plant food bit of all in her own matchless laboratory.