60 VEGETABLE FORCING 
does 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 
