The Birmingham age-herald., 1917-10-04

PidHl lOOuS, IS contained III pnOSpndL6 rock but the soluble and available phos- phorie acid is produced by treating this rock with sulphuric acid. Phosphate rock is mined in Florida South Carolina, Tennessee and elsewhere. Sulphuric acid is derived principally from pyrites or iron sulphide ores, and also as a by product of copper smelters.
 Is ground rock phosphate readily avail able as plant food?
 No. Unless changed into acid phos- phate, it is not. In the raw ground rock phosphate the food is essentially locked up in water-tight pantries. It is neces- sary, therefore, for acid to be applied to open the doors and spread the table, so to speak, before the plant ran get at it.
 Organic acids, such as are produced by decaying vegetable matter, unlock only very little at a time Other acids which could do the work are usually present in too small quantities to be of much service.
 Untreated rock phosphate is like cold molasses in jug. Though inside, it is very slow business to get a drop of it outside. In the case of rock phosphate, not more than taste can get out, whereas the plant needs a lot in order that it may feed, grow and produce a maximum crop.
 How is phosphoric acid used in the development of the plant?
 Phosphoric acid enters especially into the development of the seeds of plants. It is important to have a good healthy stalk, but unless there is sufficient sol- uble and available phosphoric acid as plant food, the plant will not set a max imum amount of fruit.
 What are the sources of potash?
 German deposits of various kinds of potash salts have been the greatest -.<x1w Al European war ont off European ship ments, the United States began to cure potash from keIp or seaweed, from alunite, feldspar, brine deposits of west ern lakes, from gases of blast furnaces, from cement works, from wood and other ashes, from tobacco stems, from waste liquors of fish factories, beet sugar man. ufacturing plants, distilleries, wool wash ing establishments and other sources. The outlook is encouraging for the con- tinued production of much potash from some of these sources even after the war.
 How is potash used in the development of the plant?
 Potash not only feeds but adds general vigor to the plant. It, therefore, aids plants to resist disease and overcome injury from parasites. Some plants like potatoes and tobacco require more potash as plant food than others.
 What is soil building?
 Frequently farmers think they have built up their soils when they have only made possible a greater use of the nat uraI store of plant food they are simply mining the plant food faster. Soils have been built up through the ages to con siderable degree by the accumulation of organic matter-animaA ST vegetable. This can still be looked to as an important means of soil building.
 Are soils generally deficient in organic matter?
 Yes. This is especially true of the south where the long, warm season fav- ors rapid decay and oxidation; therefore, organic matter is consumed faster than it Is further north. Sandy soils Is gen eral lose their organic matter moro quick ly than heavier soils. With clean crop ping, as, for example, in growing corn and cotton, much vegetable matter is not left to be turned under. especially when 1t is burned off as Is the common and unfortunate practice in the south. No stubble. stalk, grass, litter or vegetable matter should be burned off-unless 1t is for the purpose of destroying injurious insects-but should be turned under for the organic matter 1t can put in the soil
 Does turning under vegetable matter create more plant food than was taken from the soil?
 No, except in the case of legumes. Then