40 The Bulletin. 



Effect of Diffeeeistt Materials Furnishing J^itrogen and Time of 



Application. 



The experiments, the results of which are presented in Table VI, were 

 arranged to test the comparative value of dried blood and nitrate of soda 

 as nitrogen-furnishing materials in growing cotton, as well as the best 

 way of applying these. 



Nitrate of soda is a material easily soluble in water and therefore 

 quickly available for the use of plants. The questions usually raised in 

 connection Avith its use are the possibility of its loss from the soil, 

 especially sandy or open, porous soil, because of its easy solubility in 

 water and its giving out before a long-seasoned crop has made its 

 growth, thus leaving it without a supply of nitrogen before the end of 

 the growing season. Its use is most strongly advocated for short-season 

 crops, as in early truck and vegetable growing, and as a top dressing for 

 grain and for corn and cotton after growth is well advanced, or for any 

 crop when seen to be in need of a quickly-acting nitrogen-supplying 

 material. 



Dried blood, which is a fair representative of the animal and vegetable 

 materials furnishing nitrogen, as cotton-seed meal, tankage, etc., is not 

 soluble ill water and acts more slowly and for a longer time. It must 

 be changed by rotting or decomposing in the soil into nitrates before it 

 can feed the crop, and is thus likely to be effective throughout a reason- 

 able growing season. 



It has become a practice in growing many crops to apply only a part 

 of the nitrogen at the time of planting and a portion later, usually as 

 nitrate of soda, so as to keep the crop growing as rapidly as possible. 

 The tests in Table VI were planned with a view of throwing as much 

 light as possible on these questions of nitrogen fertilization. In the 

 experiments all of the phosphoric acid and potash were applied in the 

 drill before planting. On plats ll^ and 9^ one-half the nitrogen was 

 supplied as dried blood and was applied Avitli the phosphoric acid and 

 potash before planting, and one-half the nitrogen was supplied as nitrate 

 of soda and applied about July first. In plats 122 ^nd 10 ^ all of the nitro- 

 gen was furnished by nitrate of soda, one-half being applied before 

 planting, with the phosphoric acid and potash and the other half about 

 July first. On plats 13^ and 11- the nitrogen was supplied by dried 

 blood, one-half being applied before planting, \vith the phosphoric acid 

 and potash and the other half about July first. On plats 1^ and 12^ 

 four-fifths of the nitrogen was furnished by dried blood and one-fifth by 

 nitrate of soda and was all applied before planting, along with the phos- 

 phoric acid and potash. 



It is evident that there is considerable A^ariation in the different years 

 and on the different fields. In studying these results it is only fair to 

 practically disregard plat 1", field A, for it is naturally much less fertile 

 than the check plat of the same series — 8^. With this exception the 

 average table shows no marked difference in profit favoring any single 

 method of application. On the average, two applications of nitrogen, 

 one-half at planting and one-half about July 1, gave the largest increase 

 and profit. Considering the results on field B alone, and this probably 



