THE DISABILITIES OF FARMYARD MANURE.

Otago Witness, Issue 3084, 23 April 1913, Page 14

THE DISABILITIES OF FARMYARD MANURE.

It is almost heresy in the eyes of any farmer to indicate that farmyard manure, properly made, has any imperfection of any kind, except the cost of getting it out long distances, and the difficulty of securing the necessary labour; but such, however, is the case, and the best of farmyard manure must plead guilty to being balanced badly in regard to its plant food. Everything that has just been said in the previous article must be conceded, but while it has such a. beneficial effect on the physical condition of the ground, and supplies a certain amount of humus, which loosens the soil, and makes it more retentive of water, and by means of its decomposition adds heat and increases the heat-absorbing powers of the land, as a carrier of plant food it is not specially valuable. A ton of it contains only 91b to 16!b of nitrogen. 41b to 91b of phosphate, and 91b to 151 b of potash. It does not contain a sufficiency of the mineral constituents to balance its organic nitrogenous contents. Most of it is saved in the open in this Dominion, the product of dairy cows fed on pasture, fodder crons, and roots, and the lowest quoted figures in regard to nitrogen wouVl he nearest the mark, if, indeed, most of it was not washed out altogether. Supposing it contained 91b of nitrogen and the same phosnhate and potash ns is ouoted ?0 tons per acre would result in an application of 180'h of nitrogen. 1101 h of phosphate, anrl of potash. A 45-ton cron of mangolds would remove from the ground 1801 h of nitrogen. 7?lh of phosphoric acid, and 4631 b of potash. The rcmiirements of such a crop in regard to nitrogen and nhoenhate would he met. hut there is not half enough potash to renlace what is extracted, or to supply the crop. Shallow-roofed crops, like barlev and turnips, would respond freelv to the addition of superphosphate, but deeper-rooted crops, like wheat and mangolds, respond very little to such a dressing. And when one wants a healthy plant, capable of growing a fair amount

of leaf and straw, and producing a. heavy yield of well-developed grain, a wellbalanced supply of plant food is necessary —the nitrogen to produce growth, the lime, phosphate, and potash, so essential for the production of stiff straw and plump heads. It has been shown that farmyard manure cannot be regarded as well balanced, as it is deficient in potash and lime. The addition of basic slag and kainit would make it so. These manures would act .and react on each other; 2jCwt of basic slag would supply 401 b to 451 b of phcephoric acid, and 1251 bof lime per acre. The latter would help to make the phosphate in the farmyard manure available, and the addition of kainit would supply the necessary potash and increase the soluble character of the slag by 6 per cent, to 10 per cent., and make it moi’e assimilable by plants. o would, therefore, suggest the addition of these artificial manures along with any farmyard manure which is being applied in the autumn or earlv winter.