MANURING FOR WHEAT.

New Zealand Herald, Volume LI, Issue 15613, 20 May 1914, Page 14

MANURING FOR WHEAT.

BY W.S. Ix a previous article it has already been pointed out that manuring for wheat, both when applied direct to the crop and indirectly is profitable practice. The term direct 'manuring means the adding of fertilisers direct to the crop, either at time of sowing the seed or applied to the- soil immediately before the crop is sown. Indirect manuring means manure applied to to a preceding crop, and is usually applied in excess of that which is required by that crop, and tho residue of manure applied is left in the soil, to be taken up 'the succeeding crop. In the firstmentioned the manure is usually put in with a drill having a manure, attachment, and the whole process of manuring and feeding is done at the one time; while with the second the manure is sown before the seed, and is drilled through a masnure drill, either on the surface or is run through the coulters and covered in ihe same way as if sown along with the seed; Manuring Before Seeding.

When the method of manuring the soil' before the seed is sown is practised it is preferable) to allow the manure to drop direct from tie drill instead of being run through the drill coulters, as in this way the manure is more evenly distributed over the whole of the surface soil, and when the seed is sown soon afterwards the plants find available plant, food near the surface, which by this time have becom.-, partly incorporated with the soil. This method, however, is not usually practised in the ordinary routine of cropping, but is generally confined to crops which need more liberal manuring than the <- tr-ii-nary cereal crops, such, for instance, as the mangold, rape, or a similar gross feeding crop, or on soils greatly deficient in such of the plant food constituents as are absolutely fundamental to the proper development of the crops that are to be grown thereon. In this case it. is sometimes advisable to add part or the whole of the manure to the soil before sowing, the seed. '■ • , -■ . A method now adopted by many promi- ■ nent farmers, and one which is well worth i giving a fair trial when heavy dressings of artificial are being applied, is to sow broadcast part (say, half) of the manure over the surface of the land after the seedbed has been carefully prepared,_ and then, when sowing the seed, the remainder is run through the coulters' in the ordinary . way. This method has many advantages over tho application of heavy dressings all at the one time, and sown at the same • time as the crop is being, sown. First, the manure is more evenly distributed; second, there is only just sufficient manure put directly under the seed to give the plants a good start and to give them a healthy growth; thirdly, by the manure being evenly distributed through'the- whole of " the soil a more even growth is encoiiraged oil through the growing season, ending in a well-developed crop, whereas when, heavy dressings of artificials are applied with the seed when sown through the ordinary grain and manure drill the plants usually set up ft vigorous growth at the commencement, but .are "unable to continue such rapid progress, and should a dry spell come the crop suffers severely. . . On the other hand, if half of the manure is applied beforehand and the other half) own "with the seed, the plants will not only get a good start in life, but will continue to grow steadily and strongly all through, as by. the time the manure imme- ' diately under the roots of the seedlings, or that part that was sown with the seed, is used •up or .practically so, the roots will havo developed sufficiently to enable them to utilise the manure that _ has by this time become well mixed with the surface soil and is in an available form for the crop to use. Again, by an even distribution of the artificials, a more even distribution of surface roots is encouraged. Moreover, this enables the plants not only to make use of the artificials added, but also enables the plants to search for and obtain more of the plant food constituents already in the soil.

Influencing Soil Properties. : Manure may act in at least three different ways on the soil. It."may: react chemically with some soil constituent. It may influence the physical properties of the soil and' modify the bacterial 'flora, and thus indirectly affect changes ! going on in the soil. Manure is a substance consisting of plant food which, increases the fertility of the soil and rouses it to grow larger crops. It is only since the beginning of the 19th century that any accurate knowledge has been obtained of the functions of manure and the principles of manuring. The true meaning of manure is plant food. Any substance, either in • liquid state or in the form of gas, or any | other form whatever, that is classed .as , plant food is 'a manure. The simple tilling , <if the soil is one means of manuring the , soil, and in past centuries this was the , only means tho ancients had of manuring < the noil for the various crops grown in those days. Hence to cultivate means to manure. ' But in these days this method is too primitive for the modern farmer, and 13 not found sufficient to satisfy even the most sceptical, for it lias been proved over and over again that by continued experiment our knowledge of the action of manures in improving the soil is in the right direction. First, by adding to it soluble material, which plants take up from it by their roots, and by improving its mechanical condition, so as to make it a more kindly and suitable medium for the growth of crops. In most New Zealand soils phosphatic manures are much more important in the production of wheat. There seems good reason for the hypothesis that if wheat be not grown too frequently, and a judicious rotation of forage crops, root's, potatoes, leguminous crops, and temporary pastures in which clovers are. prominent be adopted, it will be. found, that the requirements of the soil in the matter of phosphates will be met liberally. Nature will go far to maintain the nitrates, and will usually bo sufficient for most cereal crops, and on most soils, except where leaching takes ' place very freely. Dressings of phosphate, " however, will bo found almost invariably to produce a profitable response in. the .;■ '• ; . Crop when applied with the seed in the ; ; .\ autumn or in the spring, for their infiuenco u- is manifold, and is especially to bo recom--1; . intended in the case of land that lias been L - badly farmed or unduly exhausted without [V , any effort being made to maintain ferUp