402 BOARD OF AGRICULTURE. [Pub. Doc. 



the case with superphosphate. It can therefore be applied 

 in large excess, and it is especially valuable on marsh lands 

 rich in humus, and for fodder crops, grasses and all crops 

 that need a gradual supply of phosphoric acid, and which 

 have a long growing period. Thomas slag can be applied in 

 such quantities that there will be sufficient available in the 

 soil each year to furnish the crop with the needed supply. 

 By this I mean that the large quanlitij of slag api)lied to the 

 soil would e(|ual the soil's phosphoric acid capital, and that 

 the amount available each year (being sufficient for the crop) 

 would equal the yearly interest on the cai)ital. 



(c) Soluble phosphoric acid should l)e used rather on 

 light, sandy soils, and on quick-growing crops, such as early 

 vegetaliles and grains. 



(rZ) Raw, undissolved phosphates have no particular 

 manurial value. 



Potash. 



(a) All the grains have great need of potash, much more 

 so than is commonly supposed. Especially is this true of 

 l)arley ; then follow in order wheat, rye and oats. 



(b) Next to the grains, meadows and grass lands gen- 

 erally have great need of potash, and from 550 to 600 pounds 

 of kainite can be applied with excellent results. An applica- 

 tion of phosphoric acid and potash to meadows causes the 

 clovers to come in, thus increasing the value of the hav and 

 the nitrogen content of the soil. 



(c) Next to the grasses, the legumes, such as peas, beans, 

 vetches, lucerne, clover and serradella, are thankful for pot- 

 ash, and must l)e Avell supplied with it in order to enable 

 them to assimilate the free nitrogen of the air. 



(d) For })()tat()es and sugar beets i)otash works better 

 u})on a h)amy rather than u[)()n a light sandy soil. 



(e) The soils most in need of potash are the marshy, 

 peaty and light sandy soils. 



(f) Potash should be applied in the autunm, if possi))le, 

 and ])loughe(l in. A simple top dressing for meadows is 

 sufficient. 



(g) Soils lacking iii lime should be dressed with this 

 material, in order to get the greatest good from the i)otash. 



