AMERICAN INSTITUTE. 265 



canals become filled, as well as the pores, and form what may be called an 

 uudrained soil, when the whole entire process of germination of the seed is 

 interfered with. At this period thorough draining is absolutely essential 

 if you would improve your soil. Excess of water always reduces the tem- 

 perature of the earth to the extent of seven degrees fahrenheit in summer, 

 which is fully equivalent to an elevation above the ocean of two thousand 

 feet. And in the winter the temperature is very high, whereas there 

 should be a difference between summer and winter of at least thirty-five 

 degrees to produce vigor in vegetation. If a soil is excessively wet, the 

 thermometer will vary throughout the year about ten degrees. Complete 

 draining, and thorough pulverization of the soil, will entirely overcome all 

 these difficulties, by establishing a direct communication between the drains 

 and interstitial canals — thus rendering it impossible for water to remain in 

 the canals, without finding the drains by gravitation. 



Figure 4 certainly indicates a soil badly cultivated, in which unbroken 

 clods, but little better than rocks exist, being not only impermeable to the 

 fibres of plants, but even the atmosphere. Therefore it would be impossi- 

 ble to say too much in favor of completely pulverizing the soil ; even the 

 most thorough draining will not supersede the absolute necessity of prop- 

 erly and eff'ectually performing this necessary operation. The acknow- 

 ledged superiority of garden, over field cultivation, is referable to the great 

 perfection to which pulverizing is carried. The celebrated Jethro Tull 

 was the first man who directed the farmers attention to this important 

 subject. He imagined that the use of manure might be entirely super- 

 seded by pulverizing eff'ectually. The success of drill husbandry is owing 

 to the fact that the soil becomes well stirred during the progress of the crop, 

 which pulverizing increases the number and size of the interstitial canals. 

 In conversation with a farmer some time since, he remarked that the inter- 

 stitial canals must be so small, that their amount could be of very little con- 

 sequence. I replied that in a soil only half pulverized, they amount to not 

 less than a quarter of the whole bulk of the soil, and that two hundred 

 cubic inches of moist soil (that is to say, one in which the pores are full of 

 water, while the canals are filled with air,) contain at least fifty cubic inches 

 of air. If this calculation be correct, in a field pulverized to the depth of 

 eight inches, every acre will retain under its surface 25,090,-560 cubic inches 

 of air. You are all aware that a disturbed soil more than fills the space it 

 previously occupied. Deep pulverization, combined with a thorough sys- 

 tem of drainage, is without doubt one of the most valuable improvements 

 in modern agriculture, and is particularly applicable on all soils lying upon 

 retentive subsoils. Before the introduction of this principle, such soils 

 were exceedingly difficult to manage, but after being drained, and pulver- 

 ized by the subsoil plow, they became very valuable, easily tilled, and pro- 

 duced remunerating crops, from the fact that in time of drought they re- 

 tained a greater supply of moisture and nourished the plants well, at the 

 same time they possessed the power of draining off" a superabundance of 

 water during excessively heavy rains. 



