MISCELLANEOUS 427 



cottonseed meal. It was, however, as valuable as cottonseed meal for the 

 growth of millet, corn, and tomatoes in Gloucester loam. It was also supe- 

 rior to processed tankage. The residual (or carry-over) effect of insoluble 

 nitrogen in UAL-37 base was greater than it was in cottonseed meal, as 

 evidenced by the yield of a second crop of millet grown in Gloucester loam. 

 A ground plastic molding resin bearing nitrogen proved of little value as a 

 N-source for crops, while the nitrogen in a resin scrap proved effective. 

 The nitrogen in garbage tankage had low value. The readiness ^^ of nitrifi- 

 cation of three organic sources of nitrogen in Sassafras sandy loam was in 

 the order named: urea, cottonseed meal, and UAL-37. Cottonseed meal 

 and UAL-37 base gave greater crop yields if added to the soil 68 days be- 

 fore planting rather than at planting time. 



In greenhouse tests ground samples of kitchen wastes or garbage ^^ were 

 less effective in crop growth than tankages with equal nitrogen content but 

 superior to cow manure and shredded stockyard manure on the same basis. 

 The residual, or second crop, effects were greater than the manures or 

 tankage. Incubatmg the wastes at 40° to 55° C (104° to 131° F) did not 

 increase the availability of the nitrogen but it did improve the texture 

 and disposed of obnoxious volatile materials. In field tests mixed kitchen 

 waste proved superior to stockyard manure but both showed similar 

 residual effects. Placing the ground wastes in the soil 30 days before plant- 

 ing the crop increased their value for the early growth of the crop. Kitchen 

 wastes ^^ were improved somewhat by liming, inoculating with active 

 cultures of decomposing bacteria, and incubation at 40° C (104° F) but 

 incubation should be discontinued when nitrogen reaches the maximum 

 percentage and before it begins to fall. 



It is evident that with proper treatment and usage a number of insoluble 

 organic nitrogen compounds can be used both as nitrogen and as a source 

 of organic material for soils. 



Sulfur dioxide from cities. Attempts ^^' ^- were made to determine 

 the effect of SO2 produced in burning coal in our cities on the soils and 

 plants about the cities. St. Louis, Mo. was selected as a city producing 

 much SO 2 due to burning high-sulfur soft coals and Philadelphia, Pa. as 

 a city producing much less due to burning low-sulfur hard coals. Samples 

 of soil and of various species of plants were taken from each of several soil 

 types. The stations from which the soil and plant samples were taken 

 ranged from the centers of the cities to localities 30 to 40 miles away. For 

 the soils, the pH values, titratable acidity, base exchange capacity, replace- 

 able calcium and magnesium, and sulfur content were determined and 

 for the plants the total sulfur, sulfate, and nitrogen content. The authors 

 conclude that soils about centers of considerable SO2 production, like 

 St. Louis, have not been noticeably altered in spite of many years of 

 exposure, and that the acidulation, if any, is much less than that due to 

 natural processes in the soil. It can be overcome by slight increases in the 

 rate of lime application. With few exceptions the total sulfur, sulfate, 



