74 The Bulletin. 



be the cheapest source from which to secure one's supply of lime. One bushel 

 of good stone or rock lime will weigh about 90 pounds, and when slaked will 

 produce about three bushels of slaked lime, which will weigh approximately 

 45 pounds per bushel. 



Pure burnt oyster-shell lime weighs about GO pounds to the bushel. When 

 it is slaked about two and one-half bushels of slaked lime is formed, which 

 will weigh about 40 pounds per bushel. 



DEEP BREAKING OF LAND. 



By C. R. Hudson. 



For a considerable number of years Southern farmers have been trying to 

 produce large, profitable crops of corn on shallow soils. The records of corn 

 growing show that they have failed. During this same period a few of the 

 more progressive farmers have been breaking their lands from 6 to 8 inches, 

 and even to 10 inches deep, and have produced from 30 to GO bushels per acre 

 at a small cost. For forty years the average depth of breaking land in North 

 Carolina has been less than 4 inches, with an average yield of about 15 bushels 

 of corn per acre. Last year the men engaged in Demonstration Work in 

 North Carolina broke 3.000 acres from G to 10 inches deep and harvested a 

 little over 40 bushels per acre. The cost was about 25 cents per bushel. 



Can we not learn a valuable lesson from the experience of these farmers? 

 Let us study, briefly, some of the advantages of a deep soil-. One of the most 

 important problems connected with crop growing is a properly distributed 

 supply of moisture. We cannot have this on shallow soils. The shallow 

 soil is soon filled with -water during rainfall. If the rains continue several 

 days, the soil stays saturated with water. This keeps out the air. (Two 

 things cannot occupy the same space at the same time.) Crops will not 

 grow vei-y long unless air gets down into the soil. Therefore the crop fails 

 during wet spells of weather. The excess of rainfall usually does much wash- 

 ing under such conditions. When the rains cease, the small amount of water 

 held in a shallow soil is soon exhausted by evaporation and by being used 

 by the crop so that the crop now suffers for lack of moisture. With a deep 

 soil these conditions do not exist. When rain conies it sinks down into the 

 lower parts of the deep soil, letting the air into the upper portions so that 

 the plants continue their growth. When dry weather prevails the deep soil, 

 by having caught previous rains, is able to supply moisture enough to keep 

 the crop green and growing. When the shallow soil is wet it is usually too 

 wet, and when dry, too di\v. 



In this section we nearly always have a wet spell or a dry spell of weather 

 during the period of crop growing. One usually follows the other. The 

 effects of both extremes can be largely overcome by having a deep seedbed. 

 Then, too, it stands to reason that there is more plant food in a deep soil than 

 in a shallow one. Again, the presence of heat, air, and moisture are essential 

 to chemical and germ action in the preparation of plant food in the soil. In 

 fact, our soils have been formed and are still being formed by the action of 

 these agencies. For this reason we say that we have soil no deeper than we 

 plow. The depths to which those penetrate in the ordinary soils are dependent 

 upon the depth of plowing. It has been proven that the roots of plants pene- 

 trate deei>er and feed deeper in deeply plowed land. These things being 

 true, we may say that a 4-inch soil has 4 inches of plant food, while an S-inch 

 soil has S inches of plant food. As a matter of fact, however, we find that 

 usually the lower portions of the deep soil do not contain as nnieh plant food 

 as the upper portions. This is because they have not been loosened up so 

 long, and hence have not had time to go through as much weathering. 



The most essential condition for a fertile soil is a constant supply of mois- 

 ture, so that a film of water can envelop the soil particles and absorb nutri- 



