ORCHARD TILLAGE, FERTILIZERS AND SHADE CROPS 7 
and in fact the burning up of such material. The classification is 
correct but we have failed to adapt our system of cultivation to the 
climatic condition. 
We are absolutely dependent upon decaying organic matter to 
keep the soil in proper physical condition; that is loamy and friable. 
But upon examination we find that this material is largely absent, 
having been literally sacrificed as a burnt offering to the gods of 
clean cultivation. 
A certain amount of cultivation is necessary but one need not 
wear out his soil in an effort to supply it. As will be seen in the 
following pages, we advocate growing a shade crop in the orchard 
during hot weather. If this system is adopted, the land should be 
plowed at least every second season, depending upon the soil. By so 
doing a sufficient amount of cultivation will be given the land and at 
the same time organic matter will be supplied. 
In the case of young orchards, unless the ground is very poor, 
some hoed crop will probably be advisable. Such crops shade the 
soil and their growth need not interfere with the proper development 
of the trees. Among the crops used are cantaloupes, potatoes, 
squashes and corn. 
We often hear it said that Colorado soils are well nigh *inex- 
haustable, and indeed it is true that they are fairly rich in many of the 
elen^ents of fertility. But we now know from experience that land 
cropped year after year to wheat becomes unprofitable, even the second 
crop of potatoes is rarely satisfactory and all fruit association men 
and local dealers know that small apples and pie peaches are becoming 
more and more common. In several sections of the state the land 
was planted continuously to wheat in the early day and as any one 
would now expect the soil became exhausted and in some instances 
the farmers faced bankruptcy. This same land is now producing 
immense crops of wheat, oats, sugar beets, potatoes and alfalfa. What 
has brought about the change ? Alfalfa was introduced about the year 
1863. It was adapted to our conditions from the first and soon large 
areas of this land were growing luxuriant crops of this unexcelled 
forage crop. The feeding of animals was then in its infancy and 
alfalfa soon became a drug on the market.. It was then found that 
alfalfa sod could be successfully broken and much to the surprise of 
*Some of our readers have no doubt seen the papers on various phases of soil fertility 
published during recent years by the Bureau of Soils of the Department of Agriculture. 
This bureau is attempting to show that there is no such thing as soil exhaustion as is 
generally understood, but rather that there is an inexhaustable supply of all of the mineral 
elements of plant food in all soils at all times. They contend that the decreased yields of 
the various crops is due to poisonous substances excreted -by the roots of plants. Thus, 
according to this view, any crop will soon poison the land to such an extent that proper 
development of the plants is hindered and decreased yields result. The remedy according 
to this theory is, naturally, a proper rotation of crops. The idea that the roots of plants 
excrete poisonous materials is an old one and one which we believe to be true with some 
plants at least. But that this is accountable for all of the many cases of unsatisfactory 
yields is difficult to believe. At any rate the writer prefers for the present to adhere vo the 
well established theories, believing that the available supply of plant food may be depleted 
and that the texture of the soil counts for much. The presence of decaying vegetable 
matter in the soil improves its physical condition, helps to set plant food free and in a 
measure takes the place of crop rotation in the orchard. This may best be supplied and 
conserved under arid conditions by the use of shade crops. 
