MANURES, LIME AND FERTILIZERS 63 
growers. It is commonly known as a hot manure and it 
decomposes very rapidly in the warm, moist soil of the 
greenhouse. Sheep manure contains about 0.76 per cent 
of nitrogen, 0.39 per cent of phosphoric acid and 0.59 per 
cent of potash. The high nitrogen content makes it 
imperative to use the manure with caution, in order to 
avoid injury to the plants. It is especially valuable for 
lettuce. The fine texture of the manure also enhances its 
value. 
Poultry manure is not often used in greenhouses, but it 
possesses special merit for lettuce on account of the large 
amount of nitrogen which it contains. Analyses show 
that hen manure contains 0.8 to 2 per cent of nitrogen, 
0.5 to 2 per cent of phosphoric acid and 0.8 to 0.9 per cent 
of potash. Like sheep manure, it cannot be used freely 
without danger of injury to the plants. The fine texture 
of chicken manure, when properly preserved, increases its 
value for mixing with greenhouse soil. 
Rate of application.—There are no rules governing the 
rate of applying manures to soils for vegetable forcing. 
The factors which enter into this problem most largely 
are, first, the cost of the manure and, second, the cost of 
transporting it to the greenhouses whether by teams, 
electric power or steam power. Wherever it can be 
delivered at low cost there is a tendency to use large 
amounts, perhaps excessive amounts, of manure. The 
annual applications range from about 25 to 60 tons of 
horse manure to the acre, 35 perhaps being the average. 
A ton of manure applied every year to 1000 square feet 
of ground should be ample to produce good crops. 
The texture of the soil, however, should be considered 
in this connection. Heavy soils demand larger and 
probably more frequent applications than light soils, for 
1 few years at least, until there is a marked increase in 
the supply of organic matter. In a new range 75 tons of 
rotten manure to the acre was applied to the Hagerstown 
