20 BOAED OF AGEICULTURE. 



Soils which are deficient in absorptive power are usun.lly 

 coarse, sandy or gravelly soils that are deficient in vegetable 

 matter and in clay. Such soils may be improved by tillage, 

 and bj^ the application of clay and vegetable matter. Such 

 soils need dressings of stable manure and muck, or the 

 turning under of green crops to furnish the needed vege- 

 table matter. The greatest obstacle to the continued crop- 

 ping of light soils with chemical fertilizers only, is the 

 exhaustion of the supply of decaying vegetable matter in 

 the soil, rendering it heavy and destitute of absorptive 

 power, and in dry seasons, crops on chemical manures are 

 more apt to fail for want of sufficient moisture than when 

 stable manure is used. Therefore, when chemicals only are 

 used, care should be taken to grow crops of extensive root 

 development, or to occasionally turn under a green crop. 



Deep tillage before the crops are planted, and during the 

 early part of the season, before the root development be- 

 comes extensive, w^ill help them to withstand drought. Deep 

 ploughing and subsoiling induce a deep root development, 

 where the soil is cool and moist, below the dry strata. Suc- 

 cessful market gardeners practice deep tillage, but they 

 always associate it Avith heavy manuring. Do not think I 

 recommend deep tillage without heavy manuring. Shallow 

 soils can only be successfully deepened by gradually work- 

 ing a little deeper each year. 



The benefits of deep tillage by subsoiling are forcibly 

 illustrated by experiments conducted by Prof. J. W. San- 

 born of the Missouri Agricultural College, and reported in 

 Bulletin No. 5 of that institution. In these experiments, 

 two adjacent plots of ^^ acre each, were ploughed 7 inches 

 deep, and one of them was subsoiled to an additional depth 

 of 9 inches, or stirred 1(3 inches deepjn all. After drought 

 had become very severe, samples of the soil of both plots 

 were taken, to a depth of 15 inches, by driving a gas-pipe to 

 that depth. The samples taken from the subsoiled plot 

 were found to contain 10.1 per cent, of moisture, while the 

 samples taken from the unsubsoiled plot contained only 8.33 

 per cent, of moisture. The yield of corn was also much 

 the best on the subsoiled plot, yielding at the rate of 70 



