No. 4.] COLLEGE AND STATION. 151 



experiments have led the investigators to urge the use of fer- 

 tilizers containing large amounts of potash. For corn four 

 cords of stable manure and one hundred pounds of muriate 

 of potash have been recommended. These experiments 

 have led a step further, and called the attention of the 

 investigator to the specific needs of different crops. Thus, 

 in a rotation of five years, — corn, corn, oats, grass, grass, 

 — it was found that the corn responded especially to 

 potash; the oats and grass, which make a quick growth in 

 the spring, to nitrate of soda ; and the second crop, largely 

 clover, to potash. 



It is now known that leguminous crops have the power 

 of taking large quantities of nitrogen from the air when the 

 conditions are favorable. Experiments have been in prog- 

 ress for a number of years to see if, by alternating legumi- 

 nous with grain crops, a sufficient amount of nitrogen could 

 be gathered to produce a reasonable crop of the former, and 

 at the same time sufficient nitrogen be left in the soil to 

 support the latter, without the aid of any applied nitrogen. 

 All of the eleven plots were fertilized with phosphoric acid 

 and potash ; some received various forms of nitrogen, and 

 to several no nitrogen whatever was applied. In the cases 

 where no nitrogen was given, the yield of both leguminous 

 and grain crops was one-quarter to one-fifth less ; the in- 

 creased yield of the plots receiving nitrogen was not, how- 

 ever, sufficient to pay for its cost. 



Experiments have been made to note the influence of sul- 

 phate and muriate of potash on the yield of garden crops. 

 Potatoes, tomatoes, spinach, lettuce and onions seem to be 

 quite noticeably more productive with the sulphate, while 

 cabbage and beets show no particular preference. 



Experiments are still in progress to determine the com- 

 parative values of different forms of phosphoric acid, as 

 found in dissolved bone-black, South Carolina floats, Flor- 

 ida phosphate, Mona guano and phospliatic slag. In these 

 experiments nitrogen and potash were applied to all the 

 plats in equal and sufficient quantities yearly. Equal money 

 values of the different phosphates were applied. At the 

 end of four years' trial the value of the different forms of 



