Instead of using the above mentioned substances singly, any or all of them may be employed together.

The muck should be as fine and free from lumps as possible, and must be intimately mixed with the other ingredients by shoveling over. The ma.s.s is then thrown up into a compact heap, which may be four feet high. When the heap is formed, it is well to pour on as much water as the ma.s.s will absorb, (this may be omitted if the muck is already quite moist,) and finally the whole is covered over with a few inches of pure muck, so as to retain moisture and heat. If the heap is put up in the Spring, it may stand undisturbed for one or two months, when it is well to shovel it over and mix it thoroughly. It should then be built up again, covered with fresh muck, and allowed to stand as before until thoroughly decomposed. The time required for this purpose varies with the kind of muck, and the quality of the other material used. The weather and thoroughness of intermixture of the ingredients also materially affect the rapidity of decomposition. In all cases five or six months of summer weather is a sufficient time to fit these composts for application to the soil.

Mr. Stanwood of Colebrook, Conn., says: "I have found a compost made of two bushels of unleached ashes to twenty-five of muck, superior to stable manure as a top-dressing for gra.s.s, on a warm, dry soil."

N. Hart, Jr., of West Cornwall, Conn., states: "I have mixed 25 bushels of ashes with the same number of loads of muck, and applied it to 3/4 of an acre. The result was far beyond that obtained by applying 300 lbs.

best guano to the same piece."

The use of "_salt and lime mixture_" is so strongly recommended, that a few words may be devoted to its consideration.

When quick-lime is slaked with a brine of common salt (chloride of sodium), there are formed by double decomposition, small portions of caustic soda and chloride of calcium, which dissolve in the liquid. If the solution stand awhile, carbonic acid is absorbed from the air, forming carbonate of soda: but carbonate of soda and chloride of calcium instantly exchange their ingredients, forming insoluble carbonate of lime and reproducing common salt.

When the fresh mixture of quick-lime and salt is incorporated with _any porous body_, as soil or peat, then, as Graham has shown, _unequal diffusion_ of the caustic soda and chloride of calcium occurs from the point where they are formed, through the moist porous ma.s.s, and the result is, that the small portion of caustic soda which diffuses most rapidly, or the carbonate of soda formed by its speedy union with carbonic acid, is removed from contact with the chloride of calcium.

Soda and carbonate of soda are more soluble in water and more strongly alkaline than lime. They, therefore, act on peat more energetically than the latter. It is on account of the formation of soda and carbonate of soda from the lime and salt mixture, that this mixture exerts a more powerful decomposing action than lime alone. Where salt is cheap and wood ashes scarce, the mixture may be employed accordingly to advantage.

Of its usefulness we have the testimony of practical men.

Says Mr. F. Holbrook of Vermont, (Patent Office Report for 1856, page 193.) "I had a heap of seventy-five half cords of muck mixed with lime in the proportion of a half cord of muck to a bushel of lime. The muck was drawn to the field when wanted in August. A bushel of salt to six bushels of lime was dissolved in water enough to slake the lime down to a fine dry powder, the lime being slaked no faster than wanted, and spread immediately while warm, over the layers of muck, which were about six inches thick; then a coating of lime and so on, until the heap reached the height of five feet, a convenient width, and length enough to embrace the whole quant.i.ty of the muck. In about three weeks a powerful decomposition was apparent, and the heap was nicely overhauled, nothing more being done to it till it was loaded the next Spring for spreading. The compost was spread on the plowed surface of a dry sandy loam at the rate of about fifteen cords to the acre, and harrowed in.

The land was planted with corn and the crop was more than sixty bushels to the acre."

Other writers a.s.sert that they "have decomposed with this mixture, spent tan, saw dust, corn stalks, swamp muck, leaves from the woods, indeed every variety of inert substance, and in _much shorter time than it could be done by any other means_." (Working Farmer, Vol. III. p. 280.)

Some experiments that have a bearing on the efficacy of this compost will be detailed presently.

There is no doubt that the soluble and more active (caustic) forms of alkaline bodies exert a powerful decomposing and solvent action on peat.

It is a.s.serted too that the _nearly insoluble and less active matters of this kind_, also have an effect, though a less complete and rapid one.

Thus, _carbonate of lime_ in the various forms of chalk, sh.e.l.l marl,[6]

old mortar, leached ashes and peat ashes, (for in all these it is the chief and most "alkaline" ingredient,) is recommended to compost with peat. Let us inquire whether carbonate of lime can really exert any noticeable influence in improving the fertilizing quality of peat.

In the case of vitriol peats, carbonate of lime is the cheapest and most appropriate means of destroying the noxious sulphate of protoxide of iron, and correcting their deleterious quality. When carbonate of lime is brought in contact with sulphate of protoxide of iron, the two bodies mutually decompose, with formation of sulphate of lime (gypsum) and carbonate of protoxide of iron. The latter substance absorbs oxygen from the air with the utmost avidity, and pa.s.ses into the peroxide of iron, which is entirely inert.

The admixture of any earthy matter with peat, will facilitate its decomposition, and make it more active chemically, in so far as it promotes the separation of the particles of the peat from each other, and the consequent access of air. This benefit may well amount to something when we add to peat one-fifth of its bulk of marl or leached ashes, but the question comes up: Do these insoluble mild alkalies exert any direct action? Would not as much soil of any kind be equally efficacious, by promoting to an equal degree the contact of oxygen from the atmosphere?

There are two ways in which carbonate of lime may exert a chemical action on the organic matters of peat. Carbonate of lime, itself, in the forms we have mentioned, is commonly called insoluble in water. It is, however, soluble to a very slight extent; it dissolves, namely, in about 30,000 times its weight of pure water. It is nearly thirty times more soluble in water saturated with carbonic acid; and this solution has distinct alkaline characters. Since the water contained in a heap of peat must be considerably impregnated with carbonic acid, it follows that when carbonate of lime is present, the latter must form a solution, very dilute indeed, but still capable of some direct effect on the organic matters of the peat, when it acts through a long s.p.a.ce of time. Again, it is possible that the solution of carbonate of lime in carbonic acid, may act to liberate some ammonia from the soluble portions of the peat, and this ammonia may react on the remainder of the peat to produce the same effects as it does in the case of a compost made with animal matters.

Whether the effects thus theoretically possible, amount to anything practically important, is a question of great interest. It often happens that opinions entertained by practical men, not only by farmers, but by mechanics and artisans as well, are founded on so untrustworthy a basis, are supported by trials so dest.i.tute of precision, that their accuracy may well be doubted, and from all the accounts I have met with, it does not seem to have been well established, practically, that composts made with carbonate of lime, are better than the peat and carbonate used separately.

Carbonate of lime (leached ashes, sh.e.l.l marl, etc.), is very well to use _in conjunction with_ peat, to furnish a substance or substances needful to the growth of plants, and supply the deficiencies of peat as regards composition. Although in the agricultural papers, numerous accounts of the efficacy of such mixtures are given, we do not learn from them whether these bodies exert any such good effect upon the peat itself, as to warrant the trouble of making a _compost_.

4.--_Experiments by the author on the effect of alkaline bodies in developing the fertilizing power of Peat._

During the summer of 1862, the author undertook a series of experiments with a view of ascertaining the effect of various composting materials upon peat.

Two bushels of peat were obtained from a heap that had been weathering for some time on the "Beaver Meadow," near New Haven. This was thoroughly air-dried, then crushed by the hand, and finally rubbed through a moderately fine sieve. In this way, the peat was brought to a perfectly h.o.m.ogeneous condition.

Twelve-quart flower-pots, new from the warehouse, were filled as described below; the trials being made in duplicate:--

Pots 1 and 2 contained each 270 grammes of peat.

Pots 3 and 4 contained each 270 grammes of peat, mixed-with 10 grammes of ashes of young gra.s.s.

Pots 5 and 6 contained each 270 grammes of peat, 10 grammes of ashes, and 10 grammes of carbonate of lime.

Pots 7 and 8 contained each 270 grammes of peat, 10 grammes of ashes, and 10 grammes of slaked (hydrate of) lime.

Pots 9 and 10 contained each 270 grammes of peat, 10 grammes of ashes, and 5 grammes of lime, slaked with strong solution of common salt.

Pots 11 and 12 contained each 270 grammes of peat, 10 grammes of ashes, and 3 grammes of Peruvian guano.

In each case the materials were thoroughly mixed together, and so much water was cautiously added as served to wet them thoroughly. Five kernels of dwarf (pop) corn were planted in each pot, the weight of each planting being carefully ascertained.

The pots were disposed in a glazed case within a cold grapery,[7] and were watered when needful with pure water. The seeds sprouted duly, and developed into healthy plants. The plants served thus as tests of the chemical effect of carbonate of lime, of slaked lime, and of salt and lime mixture, on the peat. The guano pots enabled making a comparison with a well-known fertilizer. The plants were allowed to grow until those best developed, enlarged above, not at the expense of the peat, etc., but of their own lower leaves, as shown by the withering of the latter. They were then cut, and, after drying in the air, were weighed with the subjoined results.

VEGETATION EXPERIMENTS IN PEAT COMPOSTS.

KEY A - _Weight of crops in grammes._ B - _Comparative weight of crops, the sum of 1. and 2. taken as unity._ C - _Ratio of weight of crops to weight of seeds, the latter a.s.sumed as unity._

-------------------------------------------+---------------+----+------- _Nos._ _Medium of Growth._

A

B

C -------------------------------------------+---------------+----+------- 1 }

1.61}

2 } Peat alone.

2.59} 4.20

1

2-1/2

3 }

14.19}

4 } Peat, and ashes of gra.s.s,

18.25} 32.44

8

20-1/2

5 }

18.19}

6 } Peat, ashes, and carbonate of lime,

20.25} 38.44

9

25-1/2

7 }

21.49}

8 } Peat, ashes, and slaked lime,

20.73} 42.22

10

28-1/2

9 }

23.08}

10 } Peat, ashes, slaked lime, and salt,

23.34} 46.42

11

30-1/2

11 }

26.79}

12 } Peat, ashes, and Peruvian Guano,

26.99} 53.78

13

35-1/2 -------------------------------------------+---------------+----+-------

Let us now examine the above results. The experiments 1 and 2, demonstrate that the peat itself is deficient in something needful to the plant. In both pots, but 4.2 grammes of crop were produced, a quant.i.ty two and a half times greater than that of the seeds, which weighed 1.59 grammes. The plants were pale in color, slender, and reached a height of but about six inches.

Nos. 3 and 4 make evident what are some of the deficiencies of the peat.

A supply of mineral matters, such as are contained in all plants, being made by the addition of _ashes_, consisting chiefly of phosphates, carbonates and sulphates of lime, magnesia and potash, a crop is realized nearly eight times greater than in the previous cases; the yield being 32.44 grammes, or 20-1/2 times the weight of the seed. The quant.i.ty of ashes added, viz.:--10 grammes, was capable of supplying every mineral element, greatly in excess of the wants of any crop that could be grown in a quart of soil. The plants in pots 3 and 4 were much stouter than those in 1 and 2, and had a healthy color.

The experiments 5 and 6 appear to demonstrate that _carbonate of lime_ considerably aided in converting the peat itself into plant-food. The ashes alone contained enough carbonate of lime to supply the wants of the plant in respect to that substance. More carbonate of lime could only operate by acting on the organic matters of the peat. The amount of the crop is raised by the effect of carbonate of lime from 32.44 to 38.44 grammes, or from 20-1/2 to 25-1/2 times that of the seed.

Experiments 7 and 8 show, that _slaked lime_ has more effect than the carbonate, as we should antic.i.p.ate. Its influence does not, however, exceed that of the carbonate very greatly, the yield rising from 38.44 to 42.22 grammes, or from 25-1/2 to 28-1/2 times the weight of the seed.

In fact, quick-lime can only act as such for a very short s.p.a.ce of time, since it rapidly combines with the carbonic acid, which is supplied abundantly by the peat. In experiments 7 and 8, a good share of the influence exerted must therefore be actually ascribed to the carbonate, rather than to the quick-lime itself.

In experiments 9 and 10, we have proof that the "_lime and salt mixture_" has a greater efficacy than lime alone, the crop being increased thereby from 42.22, to 46.42 grammes, or from 28-1/2 to 30-1/2 times that of the seed.

Finally, we see from experiments 11 and 12 that in all the foregoing cases it was a limited supply of _nitrogen_ that limited the crop; for, on adding Peruvian guano, which could only act by this element (its other ingredients, phosphates of lime and potash, being abundantly supplied in the ashes), the yield was carried up to 53.78 grammes, or 35-1/2 times the weight of the seed, and 13 times the weight of the crop obtained from the unmixed peat.

5.--_The Examination of Peat (muck and marsh-mud) with reference to its Agricultural Value._

Since, as we are forced to conclude, the variations in the composition of peat stand in no recognizable relations to differences of appearance, it is only possible to ascertain the value of any given specimen by actual trial or by chemical investigation.

The method _by practical trial_ is usually the cheaper and more satisfactory of the two, though a half year or more is needful to gain the desired information.

It is sufficient to apply to small measured plots of ground, each say two rods square, known quant.i.ties of the fresh, the weathered, and the composted peat in order, by comparison of the growth and _weight_ of the crop, to decide the question of their value.

Peat and its composts are usually applied at rates ranging from 20 to 40 wagon or cart loads per acre. There being 160 square rods in the acre, the quant.i.ty proper to a plot of two rods square (= four square rods,) would be one half to one load.

The composts with stable manure and lime, or salt and lime mixture, are those which, in general, it would be best to experiment with. From the effects of the stable manure compost, could be inferred with safety the value of any compost, of which animal manure is an essential ingredient.

One great advantage of the practical trial on the small scale is, that the adaptation of the peat or of the compost to the _peculiarities of the soil_, is decided beyond a question.

It must be borne in mind, however, that the results of experiments can only be relied upon, when the plots are accurately measured, when the peat, etc., are applied in known quant.i.ties, and when the crops are separately harvested and carefully weighed.