No. 7. DEPARTMENT OF AGRICULTURE. 409 



Tlie soil is a rather heavy clay loam overlying and formed from 

 the Silurio-Cambrian limestone strata of Nittany Valley, a soil 

 probably to be classed with the so-called "Hagerstown loam," which 

 forms a part of the limestone lands of northern Lancaster county and 

 of Cumberland Valley. The writer has not had opportunity to an- 

 alyze completely the rocks underlying the soil in question, but 

 analyses of samples taken from corresponding strata nearby show 

 very'suuill amounts of clay and iron, and even very little carbonate 

 uf magnesia. 



The soil used for the experiment plots was not analyzed at the 

 beginning of the experiments. It is probably represented fairly, 

 however, by samples taken from a neighboring field showing sim- 

 ilar characters. The soil sampled had never been limed nor inten- 

 siv(!ly treated with commercial fertilizers. Despite its limestone 

 origin, this soil contains only U.26 per cent, of lime and 0.35 per 

 cent, of magnesia, with merely 0.39 per cent, of carbonic acid — an 

 amount sufficient to form carbonate with barely one-fifth of the lime, 

 which, with the magnesia, must therefore be present in other states 

 of combination. Crop experience on these lands shows little need 

 for potash fertilizers, for most crops and analyses show as much as 

 .34 per cent, of potash, .039 per cent, quite available. Experience 

 shows, however, a pronounced advantage from the use of phosphates, 

 whether acidulated or non-acidulated, despite the presence of .124 

 per cent, of phosphoric acid (P0O3), an amount fully equal to the av- 

 erage in the Eastern States. Of this fully one-tenth appears to be 

 available, judging by the action of mild solvents. The soil was 

 found to contain a fair amount, 2.2 per cent., of active humus, and 

 a moderate quantity of nitrogen, .116 per cent. Of the latter, con- 

 stituent, about one-fortieth was present in the form of ammonium 

 salts and over one-tenth in the form of nitrates — the samples having 

 being taken in late summer when the land was in corn, conditions 

 favoring a large accumulation of nitrates. 



Laboratory experiments were made by mixing lime at the rate of 

 150 bushels per acre with the soil, keeping it moist for three months 

 and then allowing it to dry gradually. At the close of a year the 

 availability of the potash and phosphoric acid had been distinctly 

 increased, the active humus had been reduced nearly one-third, and 

 the proportion of nitrogen had somewhat diminished. The quan- 

 tity of ammonia was much reduced, and, despite the alkalinity of 

 the soil, the absolute quantity and the proportion of nitrate nitrogen 

 had as clearly increased. Of the large quantity of lime applied, 

 less than one-half had been converted to carbonate, a fact contra- 

 dicting the opinion of those who hold that caustic lime is sure to be 

 promptly carbonated in the soil. It should be remembered that the 

 soils bore no crops during the time of the laboratory experiments. 



In the general fertilizer experiments conducted under the ordinary 

 four-course rotation of corn, oats, wheat and hay (mixed clover and 

 timothy), four plots have received dressings of 4,000 pounds of 

 stone lime slaked after weighing and applied upon the land after 

 plowing for corn. Four others have received similar applications to 

 the wheat and the corn of 4,000 pounds of crushed limestone, har- 

 rowed into the plowed ground. In 1859 the whole farm was heavily 

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