The Springdale news., 1917-03-23
WHAT'S WHAT IN
 GOOD FERTILIZER
Information About Commercial Eer+I. hxers Which Is Worth Keeping
 For Reference.
By De F. Hungerford College of Agr,
 culture, Fayetteville.

1y Ge T iluhStfIoiu, (Ollege or AgTt-
 culture, Fayetteville.
 Fertilizers are materials that SUD. ply one or more of the three most important plant food elements-nitro- gen, phos phorous and potassium.
 Nitrogen Fertilizers.
 The common nitrogen fertilizers are nitrate of soda, sulphate of am. nonia, cotton seed meal. dried blood, tankage and cyanamid.
 Nitrate of Soda contains from 1G Q IS per cent of nitrogen It is soluble in water and therefore immediately available to the plants. The amounts applied vary from 100 to 400 pounds per acre. Because of its solubility it should be applied either at seeding time or as top dressing after the crop has come up If used AS 6 top dressing il should be put on while the plants are dry for otherwise tho leaves may be burned Recent tests have shown that nitrate of soda is very beneficial 10 apple trees when applied at the rate of five or Six pounds per tree when the flower buds begin to show a pin color
 sulphate of Anrr onia is a by.prod uct in the manufacture of coke and coal gas. Ii contains about 20 Der cent of nitrogen. which is nearly as readily available as that in nitrate of soda. Ii is used at about the same rate per acre and in much the same manner as nitrate of soda Sutphate of ammonia should not be used on acid or sour land unless lime h ap- piled with il 10 overcome the acidity
 Cotton Seed Meal has been used very extensively in the South as fertilizer but it is coming into such genera use as a stock food that only the inferior grades can now be used proftably The nitrogen content ranges from 6 10 ' per cent. and fl contains in addition % per cent of phosphoric acid and IT per cent of potash. The nitrogen Is not sosable and must decay in the soil before it can be utilized by plants For this reason applIea ton should be made sone GIT TWO weeks before the crop is planted
 Dried Blood and Tankape are nr soluble Tn the soil water and. like CO., ron seed meal. must he applied \ week or more hefore. planting time Neither it used as extensively nov as formerly Dried blood contains from  Tankaxe s more variable Its nitrogen content ranges from 10 12 per cent and phosphoric acid from 10 % per cent
 Phosphorus Fertilizers.
 The important phesphereus ferttlx- CTS are acid phosphate raw and steamed bono meal basic slag. bone tankage and raw rock phosphate
 Acid Phosphate is ground phosphate rock treated with suphuric acid There are three grades containing re. specttyely 12, 14 and l6 per cent phos- phoric acid Although the phosphoru. in acid phosphate is readily availab ble and can be Taken np by the plant as
 
 out. because the soil absorbs and holds phosphorus until the plants need it The mte of application 1. from 900 10 4o0 pounds per acre. Acid phosphate gives the best results on heavy clay land and on soil that is not acid
 Ground Bone in the natural crn- difion contains about 1 per cent of nitrogen and about 22 per cent of phoSp phoric acid. but the ma teral ordinarily sold as A fertilizer has been steamed 10 remove the fat and glue which takes out most of tho nitrogen The result is ma terial with from 24 to 27 per cent Of phosphorie acid and 1-2 to 2 per cent of nitrogen Bone phos- phates are not so available as acid phosphate and give best results on meadows and pastures
 Basic SIag Phosphate is a hyprod- net from the manufacture of steel. II contains from K to l9 per cent of sphosphoric acid and from 36 10 50 per cent of lime. The phosphorus is more available than in bones. but less available than in acid phosphate. The lime content makes il a good ferti- liner 10 use on acid soils
 Raw Rock Phosphate is the nn- treated. finely ground phosphate rock II contains from 2s to 32 per cent of phosphoric acid To he at all effective the raw rock phosphate must he ground to very fine powder. At least a5 per cent should pass through screen with 10000 openings to inc souare inch. It should be applied at the rate of 1 ,non pounds per acre once In fonr or five years. II should be thoroughly mixed with the soil by narrowing several times
 Rock Phosphate is only slowly available. If should not be used when immediate returns are needed such as on truck crops or on rented farm II is most effective on upland soils that are slightly acid and well 1ilI ,,yft n,