CHAPTER IV 
SOIL VENTILATION 
HAVE said something of soil ventilation and that 
plants cannot thrive without it. I have also said 
that plant roots must breathe or the plant will 
die. 
If soil is so compact that air cannot enter it, the 
plant is injured as much as if it had no water. 
Entirely exclude oxygen from seeds placed in the 
soil and you get no growth. If you have some ventila- 
tion but not enough, then you have the sickly plant. 
It is said that “a plant lacking in root breathing is 
drowned as effectively as an animal would be under 
water, because enough free oxygen cannot reach them.” 
Insufficient ventilation resulting from poor drainage 
destroys organic matter in the soil. 
Sufficient soil ventilation produces the necessary ni- 
trates in the soil and prevents their destruction as well. 
Air must penetrate deeply into the soil, and the pas- 
sage of the air must be both in and out of the soil. 
Soils underlaid with coarse gravel, sandy and light 
soils, are generally strong on ventilation, while compact 
clay and heavy soils are short on ventilation. 
Soil is said to be a living thing. But it is only alive 
when it is full of organic matter and porous veins, so 
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