No. 5. 



The Doctrine of Special Manures. 



163 



posed, it is put in contact with air, over a 

 large surface, and when plowed into a well 

 drained mellow soil, the surface of contact 

 is further extended. The effect of this is 

 to stop fermentation, and induce the very 

 dissimilar change of eremacausis. The tyro 

 in chemistry knows this truth. What then 

 is the origin of the loud controversy about 

 long and short dung ; in truth, nothing but 

 ignorance, if the process of fermentation en- 

 tered into the heads of the combatants as the 

 great object of either. But we are told that 

 certain forms of dung are hot and others 

 cold, and therefore the former are suited to 

 cold soils, &c. This notion has so much 

 weight with many, that I cannot pass it by 

 without notice; but it is indeed not worthy 

 of discussion. The amount of heat given 

 out by two parcels of manure in a given 

 time, depends upon the rapidity of fermenta- 

 tion, and this upon the degree of dryness, or 

 atnount of animal matter present in either 

 parcel. If the amount of animal matter in a 

 parcel of cow dung be the same as that in a 

 similar pile of horse dung, they will both 

 yield the same number of degrees of heat ; 

 if they are both wetted to the same degree, 

 they will give it out in the same length of 

 time, but if either be wetter, that will take 

 the longest time. Horse manure being drier 

 than cow dung, ferments more rapidly in 

 heap, but spread it on the soil and place it 

 under all circumstances in the same position 

 as cow dung, especially when the animals 

 I are similarly fed, and the difference vanishes. 

 j In turning them into the soil they are placed 

 in circumstances nearly similar. 

 j If however the practical man still adheres 

 to the position that it is the condition of fer- 

 mentation which is the source of the excel- 

 lence of yard manure, there is no difficulty 

 in discovering substitutes much less expen- 

 sive. I allude to this position, because the 

 idea of the mysterious influence of fermenta- 

 tion has so completely enthralled the minds 

 of many agriculturists, that there is little 

 hope of disentangling the subject by mere 

 argumentation. One of the most eminent 

 men of this school has recently dilated to 

 some extent on the subject of applying yeast 

 to the soil, as an universal manure. Masses 

 of leaves enter into a state of fermentation 

 precisely analogous to that of yard manure. 

 Straw kept moist does the same, especially 

 if watered with putrescent ditch water or 

 urine. Green weeds thrown together with 

 peat and kept moist rapidly ferment. Spent 

 jjM tanners' bark undergoes the same change, 

 ijjj Litter of any kind kept moist, or made to 

 jsutround fish, dead animals, or similar sub- 

 jjjstances, rapidly ferments. One part of dung 

 j^j|to three of peat, straw, or other waste vege- 



table matter, kept moist will throw the 

 whole into fermentation. Many other plans 

 might be described, but I trust the farmer 

 will be satisfied at all events, that there is 

 nothing mystical in the act of fermentation ; 

 and that it is very questionable, whether it 

 can take place in the soil, or be in any way 

 advantageous to his crop. 



In no good experiment has it ever been 

 found that farm yard manure failed to ad- 

 vance the crop, it has defects, but this is not 

 one of them. When, however, the land is 

 already well dunged, or very rich, its effects 

 are much less apparent, indeed the largest 

 crops have in every case been raised by other 

 means. Lime, bones, ashes, plaster, salt, 

 charcoal, nitre, and other manures, have each 

 yielded immense crops on particular occa- 

 sions, far outrivaling any thing that common 

 manure yields; but they are not certain in 

 their effects. In the ^ame way a marling, 

 claying, burnt clay, drainage, subsoiling, 

 deep plowing are often attended with marvel- 

 lous effects ; but to adopt these practices 

 with any expectation of success, requires 

 mature judgment, and a heavy outlay. Yard 

 manure does not yield very large crops by 

 itself; when assisted by good tillage and 

 other means it has done so, but alone it will 

 not give in any case extraordinary returns. 

 There are good reasons both for its uniform 

 and limited success. 



On a grain or hay farm, especially if it be 

 remote from market, the straw or hay goes 

 to the stock, and by them is converted into 

 manure. I have already given a history of 

 the ashes of hay, they contain every mineral 

 component of the next crop of grass; so the 

 ashes of any other kind of provender yield 

 the mineral substances necessary to feed the 

 future crop of the same plants. There is 

 indeed a loss, inasmuch as the animals ap- 

 propriate a considerable amount, and of the 

 most important portion, to their substance 

 and growth. The minerals are the same, 

 but the proportions are not the same. Nov*^ 

 if we regard the efficacy of the manure as 

 depending in part on these minerals, it is 

 evident that the grass or grain will be bene- 

 fitted to some extent by finding in the soil 

 an increased quantity of every mineral it 

 requires. So far the manure, by enlarging 

 the proportion of mineral matter fitted for 

 the food of plants, secures an increase of 

 crop; but this increase is within narrow 

 limits, because the minerals added in manure 

 are of sparing solubility, and are not in the 

 full proportion required by the plants. The 

 hay has been fed to growing animals, which 

 have appropriated nearly all the bone earth 

 it originally contained, for the making of 

 bone, this is necessarily lost to the manure. 



