USE OF STHAW AS A MANURE. 433 



to the crops to which it is best suited. But the explanation of most 

 of these and similar discordances is to be found in the answers to the 

 three following questions — what substances does the crop specially 

 require ? — how many of these abound in the soil ? — can the manure we 

 are about to use supply all or any of the remainder ? If it can, it maybe 

 expected to do good. Thus simply and closely are the kind of crop, the 

 kind of soil, and the kind of manure, in most cases, connected together. 



§ 10. Of manuring with, dry vegetable substances. 



The main general difference between vegetable matter o/" ^^e sa77te 

 kind^ and cut at the same age, when applied as a manure in the green 

 and in the dry state, consists in this — that in the former it decomposes 

 more rapidly, and, therefore, acts more speedily. The total effect upon 

 vegetation will probably in either case be very nearly the same. 



But if the dry vegetable matter have been cut at a more advanced 

 age of the plant or have been exposed to the vicissitudes of the weather 

 while drying, it will no longer exhibit an equal efficacy. A ton of dry 

 straw, when unripe, will manure more richly than a ton of the same 

 straw in its ripe state — not only because the sap of the green plant 

 contains the materials from which the substance of the grain is after- 

 wards formed — but, because, as the plant ripens, the stem restores to the 

 soil a portion of the saline, especially of the alkaline, matter it previous- 

 ly contained (Lee. X., § 5.) Afler it is cut, also, every shower of rain 

 that falls upon the sheaves of corn or upon the new hay, washes out 

 some of the saline substances which are lodged in its pores, and thus 

 diminishes its value as a fertilizer of the land. These facts place in 

 a still stronger light the advantages which necessarily follow from 

 the use of vegetable matter in the recent state, for manuring the soil. 



1°. Dry straw. — It is in the form of straw that dry vegetable mat- 

 ter is most abundantly employed as a manure. It is only, however, 

 when already in the ground in the state of. stubble, that it is usually 

 ploughed in without some previous preparation. When buried in the 

 soil in the dry state, it decomposes slowly, and produces a less sensi- 

 ble effect upon the succeeding crop ; it is usuallj'' fermented, there- 

 fore, more or less completely, by an admixture of animal manure in 

 the farm-yard before it is laid upon the land. During this fermenta- 

 tion a certain unavoidable loss of organic, and generally a large loss oi 

 saline matter, also takes place (see in the succeeding lecture the sec- 

 tion upon mixed animal and vegetable manures.) It is, therefore, the- 

 oretically true of dry, as it is of green, vegetable matter, that it will add 

 most to the soil, if it be ploughed in without any previous preparation. 



Yet this is not the only consideration by which the practical man 

 must be guided. Instead of a slow and prolonged action upon his 

 crops, he may require an immediate and more powerful action for a 

 shorter time, and to obtain this he may be justified in fermenting his 

 straw with the certainty even of an unavoidable loss. Thus the dis- 

 puted use of short and long du7ig becomes altogether a question of 

 expediency or of practical economy. But to this point I shall again 

 recur when treating of farm-yard manure in the succeeding lecture. 



2°. Chaff partakes of the nature of straw, but it decomposes more 

 ■lowly when buried in the soil in the dry state. It is also difficult to 



