CONSIDERATIONS REGARDING MULCHING. 33 



sun and air deprives it of the agencies most active and useful in 

 elaborating food for plants, and thus promoting fertility. 



Few people realize what a wonderful laboratory exists in the 

 soil ; how curious, how delicate and intricate are its processes, — so 

 mysterious that the skill of the chemist is yet as unable to rival 

 or reproduce that which is known as it is to detect or explain tlie 

 unknown. 



So far as facts have been ascertained the}- serve to show that, 

 even though the chemical elements of fertilit}' are supplied in 

 sufficient quantity, still the stimulating actions of heat, light, and 

 air are the leading essentials of plant growth. Moisture is a con- 

 tributory element after the fact, and can be either supplied or re- 

 served in variou* ways. To suppl}- it is the work of irrigation ; 

 to reserve it is the work of cultivation. 



It is easy to see, with but little experience, how a mulch of any 

 suitable substance that simpl}' retains moisture will counteract or 

 diminish the beneficial effects of heat, light, and air; but, for at- 

 taining the highest excellence in cultivation, we must procure the 

 lesser benetit without surrendering the absolute requisites ; and 

 there cannot be much doubt that a mulch, while it checks evapo- 

 ration, also retards the chemical activity of the soil. 



If the mulching material is of a kind which soon decays it may 

 be dug into the soil when its use as a mulch is ended. But my 

 observation is to the effect that, if this final disposal is good for 

 anything, it were better to have dug it in at the beginning rather 

 than at the end. 



Mulching may serve to keep the surface moist ; but it will be 

 found that the portion in contact with the ground is apt to mildew, 

 and encourage fungous growth, which neither indicates nor promotes 

 healthful vegetation. We are cautioned, therefore,* against the 

 use of easil}' decaying or fermenting substances. A careful ex- 

 amination of the under surface of most of these mulchings will also 

 develop the fact that it is a snug harbor for slugs, snails, worms, 

 and all minor sorts of vermin, — at least that has been m}' experi- 

 ence. 



On the other hand, if the material is one which cannot be bene- 

 ficially or properly dug into the soil, after its use as a mulch has 

 ceased, such as tan, sand, or sawdust upon light soils, then the 

 labor of spreading and afterwards gathering and removing it is by 

 no means inconsiderable. 



A coatino- two inches thick on an acre amounts to about three 



