MANURES.

Lyttelton Times, Volume XCVII, Issue 11252, 26 April 1897, Page 2

MANURES.

("Field” Contributor .) The practice of using manures has, I suppose, been in existence ever since man first realised that by continual cropping of the land he was taking from it the essential elements of plant life. It is, however, open to doubt whether manures are used in as economical and profitable a manner as they should'be, when the enormous help which science has given us, both by its geological and chemical researches, is fully considered. /Take, for example, _ the most common, and I may say, when its general replenishing powers are thought ,of, the most valuable manure, viz., farmyard. How much waste is caused by carelessness, both in its making and application. Oftener than not it is made in large open yards, free to be washed by all the rain which falls, and, even then, the good which is thus taken from it is not collected andusedasitnxightbo,butallowed to run off and waste. How often we go into stables reeking with the fumes of ammonia causing intense irritation to our eyes and nostrils, and, therefore, much more so to those of the horses which aro in them for a longer period than we. In this case the loss is two-fold; first we lose the valuable nitrogen in the ammonia, which we afterwards replace by expensive dressings of nitrate of soda or sulphate of ammonia; and, secondly, the eyes and systems of our horses are injured by these fum.es.

Wo have then to consider how we may best prevent, or at least diminish, the losses caused by washing and in other ways. In the first case we can, of course, have covered yards, and thex-e can be doubt that the manure made in these is of a much more valuable nature than that made in the open. Even in these, however, it can be improved by good management, as, for instance, by adding earth to it, so as to form thin layers, which increase its powers of retention. With open yards the same may be done, while the addition of gypsum and kainit also prevent loss of ammonia, the latter also increasing the value by the addition of the potash contained in it. It is also a good plan to have a tank so arranged that the yard can drain into it, and the liquid which collects may be pumped over the litter at intervals or used in its present form. With regard to manure heaps also, a covering of earth will diminish loss, and the addition of the substances recommended above will also help. It is best though, to cax-t, if possible, direct to the field, thus saving the expense of twice moving and the loss always occurring in a heap. On the field it should be spread and ploughed in as soon as convenient, or we again lose the volatile ammonia; while, if left in heaps for any time, the subsequent crop is likely to be patchy.

To turn now to artificial manures ; these are mostly special manures, i. e„ used to supply some one important constituent in which the soil is deficient. In the use of these the end in view should he carefully considered. If we have a backward crop, or one in the throes of insect attack, we know that prompt measures must be taken to assist it, and quick-acting substances are used, such as nitrate of soda or sulphate of ammonia. These, however, leave little, if any, of their chief constituent in the ground for any length of time, and should' be looked on in the light of strong tonics. When, however, we come to more lasting substances, their application should receive much attention, and an endeavour should be made to find out what constituents are lacking in the soil. This can be done to some extent by a knowledge of its nature and the crops "it has previously carried. By its nature can be guessed the original constituents, and by the crops it has carried an idea can be formed as to what is likely to be most required. Having got at these points as thoroughly as possible, the next tiling is to consider how best to supply the substance lacking. A knowledge of the various artificials and the ways in which they act is hero essential. The chief in general use are the two before mentioned, together with the following; —Guano, which supplies nitrogen, and in some cases phosphates, as does also meat meal, or meat guano as it is sometimes called; soot, dried blood, wool refuse, &c., which supply nitrogen also. Then come bones of various sizes, superphosphate, phosphatic slag (known as Thomas or basic slag), and ground phosphates, to which, indeed, the basic slag belongs; these all supply phosphate, as their name implies, and, in conjunction with lime, superphosphate being the most rapid in action, there is also kainit, which • supplies potash; and common salt, supplying sodium and chlorine. The latter, however, is not much use, except perhaps in the case of the mangold crop. ' The next point to consider is the method of application. In this a thorough and even distribution is most necessary. Soluble manures are able, however, to spread themselves afterwards better than those less soluble, and these latter should be very carefully put on. The time of year for applying must also bo thought of, as the slower acting manures should be applied earlier than the quicker ones, so that the food contained in them is in a suitable state for absorption by the time it is required by the plant. Blood, wool refuse, meat, guano and ground phosphates belong to the former class, and as intermediate may be taken superphosphate and kaiuite, while all ammoniacal manures are quick in action.

A word as to mixtures. Basic slag must not be mixed with guano, nitrate of soda, or sulphate of ammonia, or loss will result neither must superphosphate and nitrate of soda for the same reason. All these should be used separately, at intervals between the applications. I hope the above few notes maybe of service to those who are not quite clear as to the methods of using and action of manures, and believe that it is in the consideration of the small details of agriculture as well as in that of the greater ones that success may be obtained. I have often thought that the institution of experiments in manuring on a simple scale on large estates would be of great use to the tenants on them, as, if the results were pointed out to them, how much more clear and convincing they would bo than any amount of writing. The owners would also benefit by the greater success of the tenants, and I cannot see that the expense would be great if the experiments were well managed.