"THOMAS PHOSPHATE," OR BASIC SLAG.

Bruce Herald, Volume XXXXIV, Issue 55, 15 June 1908, Page 7

"THOMAS PHOSPHATE," OR BASIC SLAG.

(By Practical.) As the season for applying this valuable grass manure is now on, a few words regarding its application and value may bo of use to farmers. As. a fertiliser for reviving worn out, and a stimulant for new. pastures it is probably without a rival. In the North Is. land the problem of how to prevent grass running out in a few years was a very perpelxing one. I say "was" for it is no longer so, the solution having been found in the application of basic slag, or "Thomas Phosphate." In that island the effects when appliod to paddocks from which apparently all clover had disappeared, were truly wonderful, the clovers and finer grasses spring into life as if by magic. There, when selecting ground for experiments, the writer used to choose such as from which no tangible results could apparently be expected, but in every case in which the clover roots were not dead, but only dormant, slag maintained its reputation as a restorative. There is no reason why it should not be Just as efficacious here in the South, but my observations lead me to believe that the grass roots die out in this soil more quickly than in the warmer soils of the North, hence it is better to apply it either with the seed or before the grass disappears, thus ensuring some degree of permanency of pasture. In the North this can be secured for indefinite periods as far as regards white clover and top dressing of not less than 4cwt per acre if used by itself, or if used in conjunction with potash, which is more advisable, 3cwt, and about one-third of a cwt of sulphate of potash, or half to three-quarters cwt or 30 per cent, potash manure. This may bo looked upon as a fairly heavy dressing, but it should last for four or five years without renewing, and all experience has shown conclusively that one heavy dressing is more profitable and more economical than several light annual applications; for not only is the extra cost of labor saved, but in the aggregate the several light dressings would amount to more than one heavy one in, say. four years. But to do its work properly it must be put on late in the autumn or early in winter, and the ground should then bo chained harrowed. I strongly recommend t the addition of potash, more especially in the case of clover and grain crops. Clover is especially a potash-loving plant, and the mixture of slag and potash furnishes a complete plant food for it, as it also requires lime, of which there is a high percentage in its free form in, basic slag. Slag being somewhat slowly soluble requires the winter rains to wash it into the ground, where by the weak acids in the soil it is rendered soluble for the plants to absorb when they begin their growth in spring. It may safely be counted on giving off its good effects increasingly for three years, and then to last at least a year or two longer. Having said this much about its good qualities, it will not be amiss to utter a word of caution to prospective buyers. There is no manure in which there is a greater variety of grades > than Basio Slag. The best grade is that which contains from 17 to 20 per cent, of phosphorio acid, or its equivalent of 37.101 and 43.66 of phosphate of lime respectively. The next lower grade runs from 14 to 16 per cent, of phosphoric acid, with their equivalent of 30.562 and 34,928 of phosphate of lime respectively. Anything lower than that it is inadvisable to buy, for the low grade costs as much in freight as the high, and more is required to give equal results. Furthermore, the Tow grade is too often so coarse that it is next to useless as manure, for fineness is & most important feature in the value of slag. The standard of fineness as laid down by Wagner is 75 per cent, through 100 holes in the lineal inch, or 10,000 to the square inch. j Some makes are much lower than 30 rr cent, phosphate of lime, and these, need scarcely say, it would be better not to have at any price however low. Owing to the stringency of the Manure Adulturation Act no merchant will guarantee the full analysis on his invoice certificate, but will guarantee a minimum of 16 per cent, of phosphoric acid in manure that runs 18 or 18.50. This is, of course, as a measure of self protection, for if a farmer had his purchase analysed, and it was ascertained to be 18.45—& reduction of only .05 the buyer Would, if he wished to

inflict injury on the vendor, have a ground, though a very slight one, for action, the difference in value being only about threepence per ton, but still sufficient to cause trouble by one who wished to do so.

From the foregoing it will be seen how easily farmers can protect themselves if they only exercise a little cornon sense and caution.