Climate, Soils and Rotation 101 



are not as easy as in sandy soils, these types are not heavy 

 enough to prevent success with the potato. Clay soils 

 are too hard and heavy for the potato. Too much water 

 at times and poor ventilation often affect the health of 

 potatoes on clays. Careful tillage, tile drainage and the 

 incorporation of organic matter lighten clay soils until 

 they will produce good crops of potatoes in most years. 

 Except in special cases, as near-by markets, it usually 

 pays better to grow potatoes on lighter soils and use the 

 claj' soils for crops more adapted to them, as grass. 

 Muck soils, as the tule lands of California, often produce 

 large yields of potatoes. The quality is likely to be poor. 



The importance of organic matter in the soil is seldom 

 fully appreciated by American farmers. Most American 

 soils outside of the arid regions contained more organic 

 matter when first brought under cultivation than now. 

 The gradual depreciation from year to year is not noticed 

 until heavy loss in fertility has occurred. Another cause 

 which has contributed to the depreciation of American 

 soils is the low price of farm produce. The Department 

 of Agriculture estimates the cash labor income of Ameri- 

 can farmers to average about $320 a year besides the 

 items secured from the farm as house-rent, garden, and 

 the like. Too often this condition leads to robbery of 

 the farmer's capital, the soil. The settlement of the last 

 free land has led to a rise of the prices of farm products, 

 which now makes it profitable to replace and increase the 

 lost organic matter and lime fertilitj'^ of older soils. 



Organic matter has great power to absorb water and 

 hold it for the use of plants. The potato is very sus- 

 ceptible to injury from lack of water, making this property 

 of organic matter of great value. The physical nature of 

 any soil is greatly changed by organic matter. Heavy 



