182 The Principles of Fruit-growing. 
The nursery crop occupies the land for three to five years. 
During all this time the land receives no addition of organic 
matter, and finally even the roots are taken out of it. In 
very many cases the trees are planted and dug when the soil 
is wet or very dry, and, it is therefore, quickly and very se- 
riously injured in its “grain,” or its physical condition. 
Nurserymen find that if the land is rested in clover or 
grass for a few years it will again grow trees. This rota- 
tion, like all others, is a means of ameliorating the physical 
condition of the soil as well as the chemical condition of 
it. A part of the rotation must aim at the incorporation of 
humus. Therefore, every famous rotation has a “rest” crop in it. 
An incidental advantage of any rotation is the variety of 
tillage imposed by it. A rotation of tools and of methods 
and seasons of working the land, is often as important as 
the other results of alternate eropping. 
Extended figures of chemical analyses* of nursery stock 
show that the amounts of potash, phosphorie acid and _ nitro- 
gen which such stock removes from the land is really very 
small, and less than that removed by similar bulk or weight 
of corn or wheat. Experiments now being made show that 
the addition of concentrated or chemical manures to heavy 
nursery lands does not promise very important results; but 
there are greater hopes from experiments in the sowing of 
erimson clover and other cover crops in the nursery rows, 
and in the use of stable manures. There are instances of 
excellent results following the addition of stable manure to 
nursery lands between the trees in the fall. One piece of 
land so treated has grown excellent plum trees for twenty 
consecutive years. There is no necessary reason why nursery 
stock should not follow nursery stock as well as wheat fol- 
low wheat, except that the land is usually more clay-like, 
the rotation or cropping is longer, and the addition of humus 
or fiber to the soil is less. 
d. The conclusions.—The difficulty, then, is not one of amount 
*Consult 10th Rep. N. Y. State Exp. Sta. (1891), and Bull. 103, Cornell 
Exp. Sta.; also Rep. Amer. Assoc. Nurserymen, 1896, 43-45, 
