76 VEGETABLE FORCING 
large, flat piles 4 or 5 feet deep and with perpendicular 
sides. If the sides are built up straight, there will be 
practically no leaching. Water is applied to the manure 
as often as is necessary to prevent fire fanging. There 
can be no leaching in the interior of the pile, because no 
rainfall is ever heavy enough to percolate through 4 feet 
of manure. The piles should be turned once or twice 
during the process of decay to assist decomposition and 
to secure a product of finer texture. Railroad sidings 
have been constructed at some of the largest establish- 
ments so that the manure may be thrown on the compost 
piles without the expense of hauling on wagons. In 
other instances partly decayed manure is thrown from 
the cars through side openings of the greenhouse. 
Practically all growers apply the manure in August or 
September before the work of sterilization begins. A 
very successful grower at Erie, Pa., has been spreading 
short, fresh horse manure immediately after the harvest 
of tomatoes and cucumbers, and this is usually from 
August 1to1d. The soil is then plowed, limed, harrowed 
and watered. Repeated tillage and watering during the 
summer seem to have a most beneficial effect by destroy- 
ing weeds and disease germs, and these operations leave 
the soil in excellent physical and chemical condition for 
the fall and winter crops. With this plan of soil manipu- 
lation diseases did not appear for many years, although 
steam sterilization is now practiced in these houses, but 
more as a matter of insurance against loss than from any 
knowledge of serious infection by disease. 
Drying greenhouse soils——In hundreds of small grecn- 
houses the soil is permitted to become very dry during 
the summer months when the houses are not in use. 
The desiccation is particularly rapid and complete when 
the soil is on raised benches. A house temperature of 100 
degrees or more is an almost daily occurrence, and under 
such conditions only a few days are required for the soil 
