NITROGENOUS FERTILIZERS 159 



By the time the wheat crop was raised the beneficial effect 

 of the timothy sod had disappeared. 



Many kinds of garden vegetables must have a rapid 

 growth in order to have the succulence upon which their 

 value largely depends. To secure this quick growth nitrate 

 of soda gives an excellent form of nitrogen on account of its 

 readjr availability. As previously noted, however, it is not 

 an adequate substitute for organic nitrogen for all kinds of 

 garden crops. 



205. Effect of nitrate of soda on soils. — Nitrates are 

 easily leached from soils, and for that reason nitrate of soda 

 should not be applied in the autumn as it will be lost, in large 

 part, during the fall and winter. Even when applied pre- 

 paratory to planting, it should not be used in excessive quan- 

 tities at one time, but if large applications are necessary 

 apply part after the plants have made some growth. 



It has been found that the continued and abundant use of 

 nitrate of soda causes some soils to become deflocculated, 

 resulting in a puddled condition when the soil is worked wet 

 and a cloddy condition when dry. This, however, is not 

 likely to occur with any ordinary use of the fertilizer. On 

 acid soils it serves a double purpose, for it tends to correct 

 acidity. 



206. Sulfate of ammonia. — The source of supply of this 

 fertilizer is coal, which when distilled, as is done in the man- 

 ufacture of illuminating gas, or in the production of coke, 

 yields among other products ammonia from which sulfate 

 of ammonia is made. The industry has grown enormously 

 in recent years, but has by no means reached its maximum, 

 as of the hundreds of thousands of tons of coal burned an- 

 nually for the manufacture of coke in this country barely 

 more than one-half is used for the production of ammonia. 

 There are still great possibilities for obtaining nitrogen from 

 this source. 



