THE POTATO IN BRITISH COLUMBIA. 17 



Furthermore, in heavy soils it is more difficult to plant, cultivate, and dig the crop; 

 the potatoes are rough, off-type, and of poorer quality ; the potatoes are more 

 susceptible to disease and the crop does not mature as quickly. New soils are 

 excellent for potato-growing, because they are rich in organic matter and are also 

 freer of disease. However, like other soils, good drainage must be provided. 



ROTATION. 



The practising of a rotation is one of the most important factors in the growing 

 of any field crop, for two good reasons: (1) It helps to maintain the fertility of 

 the soil; (2) reduces weeds, insect pests, and diseases. In this Province farmers do 

 not realize the necessity of a systematic rotation of crops as much as they should. 

 Considered from the standpoint of disease alone, it is seldom wise to grow potatoes 

 on the same land two years in succession. In planning a rotation, as far .as it is 

 practicable each crop in the rotation should serve as a helpful preparation for the 

 one that is to follow. A successful rotation anywhere includes a legume-crop, a 

 grain-crop, and a cultivated or hoed crop. The crops should be so planned that 

 a piece of clover land is always available for potatoes. A common rotation that has 

 proved very successful is : 



First year: Grain, as a nurse-crop for alfalfa or clover. 



Second year: Clover or alfalfa. 



Third: Clover or alfalfa. 



Fourth year: Potatoes. 



Such a system of cropping keeps up the supply of organic matter and the clover 

 or alfalfa increases the nitrogen-supply. 



Fig. 9. Green Mountain potatoes (original). 

 MANURES AND FERTILIZERS. 



Manure. Manure is another important factor made use of in keeping up the 

 fertility of a soil. Barnyard manure and clover are the cheapest fertilizers for 

 potatoes. It is generally conceded that fresh manure, especially horse-manure, 

 applied to the land just before planting, tends to induce potato-scab. For this reason 

 it is preferable to manure the previous year for potatoes. However, should this 

 not be possible or convenient, the land may be covered heavily with fresh manure 

 during the winter previous to potato-planting, or a spring application of well-rotted 

 barnyard manure may be given. Whether manure will cause any such trouble or 

 not depends on whether there is any scab on the seed-potatoes or in the soil, or 



