406 ANNUAL, REPORT OF THE Off. Doc. 



applied in super-pliosphates is mncli less rapidly converted into un- 

 available form than wliere lime is lacking. It is not a very excellent 

 practice to add caustic or carbonated lime to a fertilizer containing 

 soluble phosphoric acid, before applying it to the land; for, by this 

 process, the most perfect distribution of the phosphoric acid in the 

 soil is lu-evented; a better plan is to lime first, then add the fertilizer. 

 Nevertheless, when the latter method is impracticable, there are 

 many soils in which the phosi)horic acid will be more effective in crop 

 production when lime has been added to the super-phosphates. Our 

 own limestone clay soil on the experimental farm where there is 

 much iron, is of this character. Patterson (19) reports the same 

 thing true of the red soil of the Maryland Experiment Station. If 

 ammonium salts are also present, the mixing should be performed 

 just before the application; otherwise a serious loss of nitrogen will 

 result. The writer received only a day or two ago, an announcement 

 of a preparation of ground lime coated with fused nitrate of soda, 

 to which the name "niterlime" was given. It is claimed that the 

 nitrate will prevent any reaction between the lime and the ammonia 

 and phosphoric acid of a fertilizer with which the niterlime is mixed; 

 if that proves true and the new material can be cheaply made, it will 

 obviate the chief disadvantage attending to a mixture of lime and 

 commercial fertilizer. 



Before passing to certain questions of practice, it remains to note 

 the effects of lime upon soil texture. This topic has been so fully 

 discussed in Bulletin 01, that the briefest statement at this point will 

 sufiice. Lime applied to a heavy, runny clay, that tends to puddle 

 under the pressure of the horse's foot or that of the plowshare, will, 

 if drainage has also been secured, change the texture so that the 

 puddling is avoided, the land become® more open and loamy, and 

 does not break up into hard clods when plowed. To produce this 

 elfect, rather heavy dressings are needful. Calcium carbide, whether 

 applied as fine ground limestone, leached wood ashes or marl, also 

 acts in a similar manner, but far less effectively. Recent extensive 

 experiments by Wolley (20) show that the carbonate leaves the clay 

 much less open than the caustic lime. 



On the other hand, lime tends to compact sandy soils and to make 

 them more retentive of moisture. 



Tliere is little doubt that these physical effects upon soil texture 

 are among the most important changes wrought in the soil by lime. 



In conclusion, there are several practical questions often asked by 

 correspondents, that more than most others deserve consideration at 

 this time. AVhat lime preparation should the Pennsylvania farmer 

 use? Thoughtful consideration of the earlier statements in this 



(19) Maryland Station Bulletin 66. 



(20) Jahresbincht f. Agrik-Chem., 1898, SO. 



