AGRICULTURAL UTILIZATION OF ACID LANDS. 7 
THE MYCORHIZAL FUNGI. 
It has been found that the blueberry requires an acid soil, that it 
grows luxuriantly in a mixture of peat and sand containing nitrates 
in extremely minute quantities, if, indeed, they are present at all. 
The plant bears upon its roots a fungus the microscopic threads of 
which lie partly on the outside of the root, but penetrate also into the 
living interior. While the experimental results can not as yet be 
regarded as furnishing an absolute proof, the evidence strongly indi- 
cates that the fungus takes up organic nitrogen from the abundant 
supply existing in the peat and delivers it to the plant in some 
available form. 3 
These mycorhizal fungi exist on the roots of many wild plants 
inhabiting acid peat. The extent to which they occur on the roots of 
cultivated plants that grow in acid soil is not yet known. It can 
hardly be doubted, however, that many such plants will ultimately 
be found to take their nitrogen through these fungi. Other acid- 
land plants will doubtless be found to possess the ability to use nitro- 
gen in the form of ammonia without the help of fungi. 
This outline of the probable means of nitrogen assimilation in 
acid-land plants prepares the way for the following survey of crops 
adapted to acid soils. 
CROPS ADAPTED TO ACID SOILS. 
BLUEBERRY. 
The blueberry, to which allusion has already been made, gives 
every indication of adaptability to commercial culture, now that its 
soil requirements and its peculiarities of nutrition are known. The 
establishment of a blueberry-growing industry will mean the utiliza- 
tion of sandy, acid lands in the pine barrens of New Jersey and 
similar situations now regarded as almost useless agriculturally. 
CRANBERRY: 
The cranberry is an acid-land fruit. It has a root fungus similar 
to that of the blueberry and doubtless of the same importance to the 
welfare of the plant. The lands used for cranberry culture are of a 
special kind, with such an excess of moisture and acidity that in 
comparatively few instances would they have been used for any other 
agricultural purpose. 
STRAWBERRY. 
The strawberry is now coming to be recognized as a plant that 
thrives as well, if not a little better, in soils having an acid reaction. 
The grower who appreciates this characteristic of the strawberry is 
relieved of the expense of applying lime to his land unless required 
by other plants in his crop rotation. 
