Proceedings of the Farmers* Club. 509 



original state what we may infer to be an almost insuperable 

 obstacle to tlie pushing downward of the tiny spongioles of plants. 

 When the tough subsoil is loosened it is permeated with minute roots, 

 which, as the plants die or are harvested, commence to decay ; but 

 being partially shut out from the access of air, their decomposition is 

 proportionally slow, and hence the humus or decaying organic matter 

 accumulates in the subsoil where it serves a double purpose. By its 

 continuous decomposition the humus gives off carbonic acid gas, 

 which being held in solution by water gradually acts upon and 

 liberates the valuable mineral substances so that they may be readily 

 assimilated by plants. It also absorbs the ammonia carried down by 

 rains from the manures applied to the surface soil and prevents it 

 from being washed away and lost. The percentage of soluble 

 organic matter may be considered in this connection as simply the 

 guage by which we can estimate the relative rapidity with which the 

 decomposition of vegetable substances take place in the subsoil. It 

 will be observed that the quantity of soluble organic matter is 

 greater in the Salem county sample than in that of the Mapes farm ; 

 and from this we may infer that in it the organic matter decays more 

 rapidly than in the other, and also find the cause of the smaller per- 

 centage of insoluble organic matter in the same sample. The whole 

 is explained by the looser texture of the Salem county subsoil, which 

 permits the more energetic action of air, heat and moisture. These, 

 the results obtained at the early stage at which the experiments were 

 suspended, are laid before you with no further expression of opinion 

 than this : That, incomplete as they are, they furnish proofs of 

 the propriety of hoth of the widely different modes of tillage 

 pursued in the two sections from which the specimens of sub- 

 soil were taken. The subsoil of Salem county is loose and friable, 

 permitting the roots of plants to grow easily to unknown depths ; 

 sufiiciently porous to admit deep down the action of the air, the 

 warmth of the sun and the free drainage of surplus water, and yet it 

 is dense enough to filter the fertilizing materials from the water that 

 carries them into the soil. It offers no inducement to the farmer to 

 plow a foot deep, when nature herself has loosened the ground to a 

 greater depth than his team can ever draw the share. On the other 

 hand, the hard and tenacious subsoil of the Mapes farm, bearing, when 

 dry, a closer resemblance to a brickbat than to cultivatable earth, 

 requires a far different treatment. Its owner was wise when he sought, 

 by the aid of art, to bring about in his cold and sterile subsoil those 



