POTASH IN LIQUID MANURE.

Otago Witness, Issue 3348, 15 May 1918, Page 8

POTASH IN LIQUID MANURE.

In a note on manures in the last publication of the journal of the English Board of Agriculture, attention is directed to the importance of saving all liquid manure if for no other reason than because of its richness in potash, and applying same to the land. In tire ordinary way very little potash is sold off from British farms. A 40-bushel crop of wheat contains only 121 b of pure potash (K2O) in the grain, while it contains 321 bin the straw; a 40-ton crop of mangels contains 4001 b of potash in the roots and 1501 b in the leaves; a 20ton crop of turnips contains 1101 b of potash. If the roots and straw are used on the farm most of the potash passes into the manure, as the animal retains very little. For every hundredweight of flesh laid on, a fattening animal only keeps back 2oz of the potash from its food; all the rest is excreted. Even milking stock do not take very much; 1000 gallons of milk contain only 161 b of potash. The remainder—and it is by far the greater proportion—passes into the manure. Very much of it occurs in the liquid, and is therefore liable to drain away. Hendrick has shown that 1000 gallons of liquid manure contain nearly 50lb of potash, equivalent to that present in 3c wt of kainit. In addition there is about 201 b of nitrogen, equivalent to that present in, say, 1001 b of sulphate of ammonia, and there is also a little phosphoric acid. Dairy farmers in particular should look to their liquid manure arrangements, as they feed so many roots, mangels, turnips, etc., and may easily enough have considerable wastage going on without realising the fact. Excellent results, we are told, have been obtained on dairy farms by conserving the liquid manure, and applying it to the grass land, or, if the soil is suitable, to the mangold land; it can be put on to arable land any time during the winter, and there is little danger that it will wash away, as the soil absorbs the most valuable constituents and holds them till the plant needs them. Dairy farmers possessing drains and a manure tank would do well to see that they are in order, and to make full use of the liquid collected.