60 VEGETABLE FORCING 



docs to the open ground, for our best growers have found 

 it necessary to make very heavy annual applications of 

 plant food, notwithstanding the fact that their soils, 

 which have been managed skillfully for so many years, 

 are acknowledged to be most superior in their physical 

 properties. 



It should be noted, however, that in greenhouse 

 management stable manure has been relied upon almost 

 wholly as the source of plant food, and it has also been 

 the means of creating and maintaining physical condi- 

 tions which are regarded ideal for greenhouse cropping. 

 The action of the manure in decomposing also has a sani- 

 tary influence on the soil, and the presence of the organic 

 matter is essential to the bacterial life. There are scores 

 and perhaps hundreds of vegetable growers who believe 

 that manure properly used meets all the requirements of 

 greenhouse soils and of greenhouse crops. It has been 

 the chief source of organic matter as well as of plant food. 



Rhode Island experiments. Interesting experiments 

 with fertilizers, manure, cut hay and cut straw were made 

 at the Rhode Island station, and reported in Bulletins 107 

 and 128 of that station. The greenhouse bench was 

 divided into four plots. Horse manure was applied to 

 No. 1 at the rate of 75 tons to the acre. Thirteen pounds 

 of cut hay or cut rye straw (1^-inch lengths) was used 

 on No. 2 and No. 3, in addition to various chemicals 

 which constituted a complete fertilizer. No. 4 was also 

 treated with chemicals, but the hay or straw was omitted. 

 Radishes, tomatoes, cucumbers and carnations were 

 grown in the series of experiments which were conducted 

 for two seasons. The decreasing yields of plot 1, as each 

 season advanced, compared with the other plots indicated 

 that "possible denitrification and the loss of some of the 

 nitrogen in a gaseous condition, also the fact that suffi- 

 cient time had now elapsed for a considerable degree of 

 decomposition of the cut straw to occur, which may have 



