FIELD CROPS. 429 



secured was at the rate of 15 bu. per acre. In 1906 wheat was plowed under, 

 fertilizers applied, and the land planted to Black Seeded Blue Ribbon cotton. 

 The results of these fertilizer tests for 1906, 1907, and 1908 are given in tables. 



When nitrogen alone was api>lied an increase of $11.07 per acre above the 

 check test was secured the first year, and of $6.48 the second year, while the 

 third year a loss of $3.56 per acre was sustained. It is concluded from the 

 results that while nitrogen is highly essential on this soil it must be combined 

 with acid phosphate to give the best results. A plat receiving only nitrogen for 

 3 years yielded at the rate of 450 lbs. of seed cotton in 1908, while another plat 

 having received in addition to cotton-seed meal and nitrate of soda, acid 

 phosphate and potash in 1906 and 1907, yielded at the rate of 954 lbs. of seed 

 cotton per acre. When used as the only source of nitrogen, nitrate of soda 

 gave the best results, but cotton-seed meal showed the better residual effect. 

 The author found that wherever nitrate of soda was used under cotton the crop 

 grew more vigorously from the start than without this treatment, and he there- 

 fore recommends the use of nitrate of soda on cotton at the rate of 25 to 50 

 lbs. per acre. In 1908, when sulphate of ammonia and nitrate of soda were 

 compared as top-dressings it was shown that the yields where these two sub- 

 stances were used were the same, but that the sulphate in the early spring 

 was much slower in its action than the nitrate. 



Observations on the use of acid phosphate showed that it was profitable only 

 to a certain limit, and that for this type of soil, which is low in humus, this 

 limit ranged from 400 to 500 lbs. per acre. It is stated that acid phosphate 

 aside from its value as a plant food is of great advantage in hastening the 

 maturity of cotton, and it is shown that this is borne out by the tabulated 

 results. 



The use of potash gave only small returns, and it is believed that only small 

 quantities should be used in mixed fertilizers intended for cotton. Plats receiv- 

 ing manure from cattle fed cotton-seed meal and corn silage produced the 

 highest yields and the highest net gain, although no manure was applied the 

 third year and no other fertilizer was applied with the manure than acid phos- 

 phate. The manure was applied at the rate of 8 tons per acre and the acid 

 phosphate at the rate of 352 lbs. in 1906. In 1907, S tons of manure was again 

 used and 704 lbs. of acid phosphate, and in 1908 only 352 lbs. of acid phosphate 

 was used. The data show that the residual effect of commercial fertilizers is 

 comparatively small, while that of manure is much more lasting. 



In one test with lime costing $7.50 per ton, there was a net gain for 3 years 

 of $9.46 as due to the lime. The author concludes from his observations that 

 lime not only assists the leguminous plants in accumulating nitrates in large 

 amounts in the soil but aids also in some way in keeping this nitrogen from 

 being washed out during the winter. Lime is considered one of the essentials 

 for a complete fertilizer on this soil, and it is recommended that farmers apply 

 lime at least once every 4 years to their cotton soils. 



The results of the work so far are sunmiarized with the statement that the 

 average amount of commercial fertilizer used on this soil, which is about 400 

 lbs. per acre, is not the most economical and that larger applications would be 

 more profitable. Suggestions for the home mixing of fertilizers for different 

 types of soil are given. 



The seed of Eruca sativa and its extraction residues, S. H.\ls and J. F. 

 GkAxM {LuiuIw. Vcii^. Stnt., 10 (IDOU), Xo. S-',, piK J07-,i/.5).— Descriptions of 

 this plant and its seeds by different authors are briefly reviewed and the com- 

 position of the seed and of the material remaining after the oil is extracted is 

 reported. Four samples of extraction residues contained on an average 10.53 

 per cent of moisture, 2.53 per cent of fat, 39.50 per cent of protein, 29.85 per 



