SOILS AND FERTILIZERS 491 



early spring, require relatively more nitrogen than phosphorus since 

 nitrification in the soil is not taking place actively at these seasons. 



Oats. There are two methods of fertilizing oats applicable to 

 different conditions. The first method* is suited to all soils, while 

 the second must vary with the farming conditions and the soil. The 

 first method consists of applying phosphoric acid and potash to fall 

 oats at the time of seeding. 



Tobacco. As a fertilizer for tobacco farmyard manure occu- 

 pies a leading position, both on account of its comparative cheapness 

 and its great effectiveness; a position which would seem to justify 

 the giving of special attention to the production and care of 

 manure. 



When manure is not obtainable chemical fertilizers may be 

 used with excellent temporary effect, but with a reduction of net 

 profit as compared with that which it is possible to obtain by the 

 use of manure. 



At the present stage it appears that the greatest total yield as 

 well as the greatest net profit has been produced by a fertilizer con- 

 taining nitrogen, phosphorus and potassium in approximately the 

 same ratio to each other in which they are found in farmyard man- 

 ure, although the cost of such a fertilizer is enormously increased 

 by reason of the large quantity of nitrogen required. Whether it 

 may be possible to reduce the amount of nitrogen in the fertilizer, 

 through the growing of clover or other leguminous crops in rotation 

 with tobacco, remains to be seen. 



As a carrier of nitrogen sodium nitrate appears to be much 

 more effective for tobacco than tankage, but tankage is the material 

 almost universally employed for this purpose in the compounding 

 of ready mixed fertilizers. As the nitrogen in these fertilizers costs 

 the farmer as much or more than that in sodium nitrate it would 

 seem to be wise to purchase and use the more effective material. 



In Connecticut Russian or hairy vetch has been found to be an 

 excellent cover crop for tobacco. This legume was found to be re- 

 sistant to cold, heat, and drought; occupied the ground during the 

 fall, winter, and spring; decayed rapidly when turned under; and 

 enriched the soil by its ability to "fix" or utilize atmospheric nitrogen 

 when properly inoculated that is, when the bacteria were present 

 to cause the formation of root nodules. As a preventive of wind 

 and water erosion the matlike growth of hairy vetch gives it great 

 value ; as a source of humus its extensive root system and the readily 

 decomposable nature of the whole plant are peculiar advantages, 

 and it seems to possess in addition, on land successively cropped to 

 tobacco, a green-manuring value considerably above its purely 

 chemical content and the physical improvement of the soil resulting 

 from its use. The full nature and amount of these benefits will 

 require more extensive tests. 



Potatoes. Scarcely any plant is more affected by a deficiency 

 of potash in the soil than the potato. It is a great feeder on potash. 

 From experiments recently made in Germany the conclusion ia 

 drawn that muriate of potash of itself does not lessen the starch COR- 



