Pine Bluff daily graphic., 1917-04-04
WHAT N
 GOOD FERTILIZER
Information About Commercial Fef4t- Ikxsfs Which 10 Worth Keeping
 For Reference.


 For Reference.
 By pe F. Hungsgford, College of Asrf
 culture, Fayetteville.
 Fertilizers are materials that sup ply one CT more of the three most important plant food elements-nitro zen, phosphorous and potassium
 Nitrogen Fertilizers
 The common nitrogen fertilizers are nitrate of seda, sulphate of am moniA ooeton ssed meal, dried blood, taakass and cyanamid.
 Ntkfate Of soda contains from 1s ao 10 per ssat 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 it's solubfhty it should be applied either at seeding time or as a top dressing after the crop has come up. If used as 2 top dressing 1t 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 to apple trees when applied at the rate of five or six pounds per tree when the flower buds begin 10 show pin color.
 Susphate of Ammonia is by-prod- uct in the manufacture of coke and coal gas. It contains about 20 per cent of nitrogen, which n nearly as readily available as that in nitrate of soda It is used at about the same rate per acre and in much the same manner as nitrate of soda. Sulphate of ammonia should not be used on acid or sour land unless lime is ap- piled with it to overcome the actdity.
 Cotton Seed Meal has been used very extensively in the South as a fertilizer, but 1t is coming into such general use as stock food that only the inferior grades can now be used proftably. The nitrogen content ranges from 6 to per cent, and it contains in addition 2.5 per cent of phosphoric acid and IT per cent of potash. The nitrogen is not soluble and must decay in the soil before 1t can be utilized by plants. For this reason application should be made one or two weeks before the crop is planted.
 Dried eieod and Tankaee are no. soluble fin the soil water and. like co., ton seed meal, must be applied a week or more before planting time. Neither is used as extensively now as formerly. Dried blood contains from 10 to 13 per cent of nitrogen Tankage is more variable. It's nitrogen content ranges from 4 to 12 per cent and phosphoric acid from to 20 per cent.
 Phosphorous Fertilizers.
 The important phosphorous fertiix- CTS are acid phosphate, raw and steamed bone meal, basic slag, boae and raw rock phosphate.
 Acid Phosphats is ground phosphate rock tre Ited with sulphuric acid. There are three grades containing re- spec4iyely 12, IA and 16 Der cent phos- phorio acid. Although the phosphorus in acid phosphate Is readily available and can be taken up by the plant as soon as 1t is applied. it Is not leached out, because the soil absorbs and holds phosphorus until the plants need 1t. The rate of application is from 200 to 400 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 con- dition contains about 4 per cent af nitrogen and about 22 per cens of phosphoric acid. but the ma. teral ordinarily sold as a fertilizer has been steamed to remove the fat and glue which takes out most of the nitrogen. The result is a ma- terial with from 24 to 27 per cent oe phosphortc acid and 1-2 to 2 per cent of nitrogen. Bone phos- plates are not so available as acid phosphate and give best results on meadows and pastures.
 Basic sIas Phosphate is a by-prod- uct from the manufacture of steel. It contains from IS to 19 per cent of phosphoric acid and from 35 to 50 per cent of lime. The phosphorus is more available than in bones, but less available than in acid phosphate. The limo content makes it a good ferti- lizeF to use on acid soils.
 Raw Rock Phosphate is the un. treated, finely ground phosphate rock. It contains from 28 to 32 per cent of phosphoric acid. To be at all effective the raw rock phosphate must be ground to very fine powder At least 95 per cent should pass through a screen with 10000 openings to the souaFe inch. It should be applied at the rate of 1000 pounds per acre once in four or five years. It should be thoroughly mixed with the soil by several times.
 Rock Phosphate is only slowly available. It should not be used IL -