ABSTRACTS OF BULLETINS OF THE AGRICULTURAL EXPERIMENT STATIONS IN THE 



Alabama College Station, Bulletin No. 16 (New Series), June, 1890 (pp. 20). 



Some conclusions from experiments with fertilizers, J. S. 

 Newman (pp. 3-16). — " Under a jailicioas rotation of crops, including 

 those which are humus-supplying, little else than phosphates need be 

 purchased by the corn and cotton grower " in Alabama. Suggestions 

 as to rotation and a discussion of the importance of leguminous plants 

 for this purpose, directions for the most advantageous use of pea vines, 

 cotton seed, stable manure, and phosphate, and formulas for compost- 

 ing the last three for corn, cotton, aud other crops are given. 



The following is a summary of conclusions from experiments by the 

 station during six years. They apply, of course, under the conditions 

 of soil, fertilizers, and crops there prevailing : 



rhosphatic fertilizers. — Phosphoric acid leaches bnt little, if any, upon clay soils or 

 those haviiij^ clay subsoils, bnt does leach throngh sandy soils with sandy snbsoils. 

 Citrate-soluble phosphoric acid possesses eqnal agricultural value with water-soluble. 

 The phosphoric acid from tloats or phosphate rock ground to au impalpable powder, 

 gradually becomes available in the soil, bnt produces very little effect upon the first 

 crop. The availability of the phosphoric acid in floats is hastened by iise with cotton- 

 seed meal. Plants are indifferent as to the sources from which available phosphoric 

 acid is derived. 



Xiiroge)ioH8 fertilizers. — Nitrogen leaches rapidly through sandy soil unless occupied 

 by feeding roots or underlaid by clay subsoil. Plants are indi-fferent as to the sources 

 from which their supply of nitrogen is derived, but those sources which yield a sup- 

 ply gradually, as needed by the plant, are best suited to our long season of growth. 

 Of the commercial sources of nitrogeu, cotton-seed meal is cheapest and most reliable. 

 It yields its plant food more gradually than either the mineral or animal sources. 



Cow-pea as a fertilizer. — Pea vines, grown upon the land and left to protect the sur- 

 face until preparatiou is made for the next crop, furnish the cheapest source of nitro- 

 gen in the most desirable condition. Thus grown and treated they furnish the most 

 reliable and practicable means of improving worn lands. Pea vines cut for hay, leav- 

 ing the stubble and roots on the laud, benefit the soil more than turning them in 

 greeu during the sunuuer. They pay best when left upon the surface till the laud is 

 needed for another crop. 



Potash fertilizers.— Potash applied to the soil of this station has not been profitable 

 except during drouth. Its principal benefit seems to result from its aflinity for 

 moisture. Plants seem indifferent as to the source of supply from which they de- 

 rive the potash needed. 



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