OATS 19 



soil. It is also a slow method, but the reported invention of a 

 machine for sowing several rows at one time may possibly over- 

 come this objection. 



22. Prevention of winter-killing. — Since Red Rust- 

 proof oats are sometimes thimied, or even killed com- 

 pletely, by cold weather in winter, methods of decreasing 

 this injury are important. Oats are more frequently win- 

 ter-killed on account of heaving, or lifting of the soil and of 

 the young plants when the ground freezes, than from the 

 direct effects of low temperatures. Heaving is due to 

 the expansion in freezing of the water in the soil. Every 

 one has noticed on a frosty morning the little icicles pro- 

 jected upward from a spot of wet. clayey land. Often these 

 icicles lift on their summits particles of soil. By this 

 same process of expansion of soil-moisture in freezing, 

 young plants are lifted. This heaving is worst in soils 

 that contain the most water; that is, in clay spots and 

 where the drainage is poor. 



Means of decreasing winter-killing of oats are : (1) plant- 

 ing in depressions or unfilled furrows (the open-furrow 

 system) ; (2) improved drainage ; (3) selection of hardy 

 varieties or strains ; (4) the use of the roller to settle the 

 lifted plants into closer contact with the soil. 



23. Quantity of seed. — On account of the ability of the 

 oat plant to throw out an indefinite number of shobts or 

 culms, and thus to utilize whatever space may be avail- 

 able, the thickness of sowing does not directly determine 

 the rate of yield. From 4 to 16 pecks to the acre may be 

 taken as the extreme limits. The quantity of seed usu- 

 ally advisable for broadcast sowing is between 1^ and 

 2^ bushels per acre. By using the grain drill, this may 



