Talks on Manures - Part 27
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Part 27

[Note 3: The manures termed superphosphate of lime, phosphate of pota.s.s, phosphate of soda, and phosphate of magnesia, were made by acting upon bone-ash by means of sulphuric acid in the first instance, and in the case-of the alkali salts and the magnesian one neutralizing the compound thus obtained by means of cheap preparations of the respective bases. For the superphosphate of lime, the proportions were 5 parts bone-ash, 3 parts water, and 3 parts sulphuric acid of sp. gr.

1.84; and for the phosphates of pota.s.s, soda, and magnesia, they were 4 parts bone-ash, water as needed, 3 parts sulphuric acid of sp. gr.

1.84, and equivalent amounts, respectively, of pearl-ash, soda-ash, or a mixture of 1 part medicinal carbonate of magnesia, and 4 parts magnesian limestone. The mixtures, of course, all lost weight considerably by the evolution of water and carbonic acid.]

[Note 4: Made with unburnt bones.]

[Note 5: In this first season, neither the weight nor the measure of the offal corn was recorded separately; and in former papers, the bushels and pecks of total corn (including offal) have erroneously been given as dressed corn. To bring the records more in conformity with those relating to the other years, 5 per cent, by weight, has been deducted from the total corn previously stated as dressed corn, and is recorded as offal corn; this being about the probable proportion, judging from the character of the season, the bulk of the crop, and the weight per bushel of the dressed corn. Although not strictly correct, the statements of dressed corn, as amended in this somewhat arbitrary way, will approximate more nearly to the truth, and be more comparable with those relating to other seasons, than those hitherto recorded.]

These were the results of the harvest of 1844. The first year of these since celebrated experiments.

If Mr. Lawes expected that the crops would be in proportion to the minerals supplied in the manure, he must have been greatly disappointed.

The plot without manure of any kind, gave 15 bushels of wheat per acre; 700 lbs. of superphosphate of lime, made from burnt bones, produced only 38 lbs. or about half a bushel more grain per acre, and 4 lbs. _less_ straw than was obtained without manure. 640 lbs. of superphosphate, and 65 lbs. of commercial sulphate of ammonia (equal to about 14 lbs. of ammonia), gave a little over 19 bushels of dressed wheat per acre. As compared with the plot having 700 lbs. of superphosphate per acre, this 14 lbs. of available ammonia per acre, or, say 11 lbs. nitrogen, gave an increase of 324 lbs. of grain, and 252 lbs. of straw, or a total increase of 576 lbs. of grain and straw.

On plot No. 19, 81 lbs. of sulphate ammonia, with minerals, produces 24 bushels per acre. This yield is clearly due to the ammonia.

The rape-cake contains about 5 per cent of nitrogen, and is also rich in minerals and _carbonaceous matter_. It gives an increase, but not as large in proportion to the nitrogen furnished, as the sulphate of ammonia. And the same remarks apply to the 14 tons of farm-yard manure.

We should have expected a greater increase from such a liberal dressing of barn-yard manure. I think the explanation is this: The manure had not been piled. It was probably taken out fresh from the yard (this, at any rate, was the case when I was at Rothamsted), and plowed under late in the season. And on this heavy land, manure will lie buried in the soil for months, or, if undisturbed, for years, without decomposition. In other words, while this 14 tons of barn-yard manure, contained at least 150 lbs. of nitrogen, and a large quant.i.ty of minerals and carbonaceous matter, it did not produce a bushel per acre more than a manure containing less than 12 lbs. of nitrogen. And on plot 19, a manure containing less than 15 lbs. of available nitrogen, produced nearly 4 bushels per acre more wheat than the barn-yard manure containing at least _ten times_ as much nitrogen.

There can be but one explanation of this fact. The nitrogen in the manure lay dormant in this heavy soil. Had it been a light sandy soil, it would have decomposed more rapidly and produced a better effect.

As we have before stated, John Johnston finds, on his clay-land, a far greater effect from manure spread on the surface, where it decomposes rapidly, than when the manure is plowed under.

The Deacon was looking at the figures in the table, and not paying much attention to our talk. "What could a man be thinking about," he said, "to burn 14 tons of good manure! It was a great waste, and I am glad the ashes did no sort of good."

After the wheat was harvested in 1844, the land was immediately plowed, harrowed, etc.; and in a few weeks was plowed again and sown to wheat, the different plots being kept separate, as before.

The following table shows the manures used this second year, and the yield per acre:

Experiments at Rothamsted on the Growth of Wheat, Year After Year, on The Same Land.

Table II.--Manures and Produce; 2nd Season, 1845. Manures and Seed (Old Red Lammas) Sown March 1845.

Manures: FM Farmyard Manure.

SiP Silicate of Pota.s.s.[1]

PhP Phosphate of Pota.s.s.[2]

SPL Superphosphate of Lime.[2]

B-A Bone-ash.

MAc Muriatic Acid.

G Guano.

SAm Sulphate of Ammonia.

MAm Muriate of Ammonia.

CAm Carbonate of Ammonia.

RC Rape Cake.

T Tapioca.

---+--------------------------------------------------------------------+

P

Manures per Acre.

l +-----+----+----+----+----+----+------+------+------+------+----+----+ o

t

s

FM

SiP

PhP

SPL

B-A

MAc

G

SAm

MAm

CAm

RC

T

---+-----+----+----+----+----+----+------+------+------+------+----+----+

Tons.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs.

0

Mixture of the residue of most of the other manures.

1

..

112

..

..

..

..

..

224

..

..

560

..

2

14

..

..

..

..

..

..

..

..

..

..

..

3

Unmanured.

..

..

..

..

..

..

..

..

..

..

4

..

..

..

..

112

112

..

112

..

..

..

..

5[4]{1 Unmanured.

..

..

..

..

..

..

..

..

..

{2 ..

..

..

..

..

..

..

..

..

252[3]

..

..

6

..

..

..

112

..

..

..

112

..

..

560

..

7

..

..

..

112

..

..

..

112

..

..

..

560

8

..

..

..

..

..

..

..

112

..

..

560

..

9

..

..

..

..

..

..

..

168[5]

166[5]

..

..

..

10

..

..

..

..

..

..

..

168[6]

168[6]

..

..

..

11

..

..

..

280

..

..

..

224

..

..

560

..

12

..

..

280

..

..

..

..

224

..

..

..

..

13

..

..

..

..

..

..

336[7]

..

..

..

..

..

14

..

..

..

..

..

..

672[8]

..

..

..

..

..

15

..

..

..

..

224

224

..

224

..

..

..

..

16

..

..

..

224

..

..

..

56

56

..

560

..

17

..

..

..

224

..

..

..

112

112

..

280

..

18

..

..

..

336

..

..

..

112

112

..

..

..

19

..

..

..

..

112

112

..

112

..

..

390

..

20

Unmanured.

..

..

..

..

..

..

..

..

..

..

21}

Mixture of the residue of most of the

..

..

..

..

..

22}

other manures. ..

..

..

..

..

..

..

..

..

---+-----+----+----+----+----+----+------+------+------+------+----+----+

Produce: Wt/Bu Weight per Bushel.

OC Offal Corn.[5]

C Corn.

TC Total Corn.

S&C Straw and Chaff.

TP Total Produce.

TP/C&S Total Produce (Corn and Straw).

OCD Offal Corn to 100 Dressed.

C100 Corn to 100 Straw.

----------------------------------+---------------+-----+----+----

Increase per

Produce per Acre, etc.

Acre by Manure.

P --------------+----+----+----+----+---------------+

l Dressed corn.

o --------+-----+

TP

t Qty.[5]

Wt/Bu

OC

TC

S&C

TP

C

S&C

C&S

OCD

C100

s --------+-----+----+----+----+----+----+-----+----+-----+----+---- Bu. Pks.

lbs.

lbs.

lbs.

lbs.

lbs.

lbs

lbs.

lbs.

32 0

56.5

159

1967

3977

5944

526

1265

1791

10.9

49.5

0 26 1

54.8

248

1689

3699

5388

248

987

1235

17.3

45.7

1 32 0

56.8

151

1967

3915

5882

526

1203

1729

8.9

50.2

2 23 0

56.5

131

1441

2712

4153

..

..

..

8.7

53.1

3 29 2

58.0

161

1879

3663

5542

438

951

1389

9.4

51.3

4 22 2

57.5

134

1431

2684

4115

-10

-28

-38

10.1

53.3

1}5 26 3

57.3

190

1732

3599

5331

291

887

1178

14.2

48.1

2} 28 2

57.8

214

1871

3644

5515

430

932

1362

14.1

57.3

6 26 2

57.0

161

1682

3243

4925

241

531

772

11.3

51.9

7 27 0

56.3

164

1716

3663

5379

275

951

1226

14.0

46.9

8 33 1

58.3

187

2131

4058

6189

690

1346

2036

10.2

52.5

9 31 3

56.3

191

1980

4266

6216

539

1554

2093

12.3

46.4

10 30 3

56.0

158

1880

4101

5981

439

1392

1831

11.3

45.8

11 28 2

55.8

264

1842

4134

5976

401

1422

1823

17.8

44.5

12 25 0

56.3

152

1558

3355

4913

117

643

760

12.0

46.4

13 27 1

57.5

176

1743

3696

5439

302

981

1286

16.2

47.1

14 32 3

57.3

209

2103

4044

6147

662

1332

1994

11.8

52.0

15 32 2

56.3

182

2028

4191

6219

587

1479

2066

11.1

48.4

16 32 0

55.8

299

2093

3826

5919

652

1114

1766

15.2

54.7

17 33 1

56.5

180

2948

3819

3867

607

1107

1714

11.2

53.6

18 34 3

57.0

133

2114

4215

6329

673

1503

2176

9.1

50.2

19 24 2

56.0

113

1495

3104

4599

54

392

446

9.7

48.2

20 .. ..

..

..

..

..

..

..

..

..

..

..

21 .. ..

..

..

..

..

..

..

..

..

..

..

22 --------+-----+----+----+----+----+----+-----+----+-----+----+----

[Note 1: The silicate of pota.s.s was manufactured at a gla.s.s-house, by fusing equal parts of pearl-ash and sand. The product was a transparent gla.s.s, slightly deliquescent in the air; it was ground to powder under edge-stones.]

[Note 2: The manures termed superphosphate of lime and phosphate of pota.s.s, were made by acting upon bone-ash by means of sulphuric acid, and in the case of the pota.s.s salt neutralizing the compound thus obtained, by means of pearl-ash. For the superphosphate of lime, the proportions were, 5 parts bone-ash, 3 parts water, and 3 parts sulphuric acid of sp. gr. 1.84; and for the phosphate of pota.s.s, 4 parts bone ash, water as needed, 3 parts sulphuric acid of sp. gr.

1.84; and an equivalent amount of pearl-ash. The mixtures, of course, lost weight considerably by the evolution of water and carbonic acid.]

[Note 3: The medicinal carbonate of ammonia; it was dissolved in water and top-dressed.]

[Note 4: Plot 5, was 2 lands wide (in after years, respectively, 5_a_ and 5_b_); 5.1 consisting of 2 alternate one-fourth lengths across both lands, and 5.2 of the 2 remaining one-fourth lengths.]

[Note 5: Top-dressed at once.]

[Note 6: Top-dressed at 4 intervals.]

[Note 7: Peruvian.]

[Note 8: Ichaboe.]

The season of 1845 was more favorable for wheat, than that of 1844, and the crops on all the plots were better. On plot No. 3, which had no manure last year, or this, the yield is 23 bushels per acre, against 15 bushels last year.

Last year, the 14 tons of barn-yard manure gave an _increase_ of only 5 bushels per acre. This year it gives an increase of nearly 9 bushels per acre.

"Do you mean," said the Deacon, "that this plot, No. 2, had 14 tons of manure in 1844, and 14 tons of manure again in 1845?"

"Precisely that, Deacon," said I, "and this same plot has received this amount of manure every year since, up to the present time--for these same experiments are still continued from year to year at Rothamsted."

"It is poor farming," said the Deacon, "and I should think the land would get too rich to grow wheat."

"It is not so," said I, "and the fact is an interesting one, and teaches a most important lesson, of which, more hereafter."

Plot 5, last year, received 700 lbs. of superphosphate per acre. This year, this plot was divided; one half was left without manure, and the other dressed with 252 lbs. of pure carbonate of ammonia per acre. The half without manure, (5a), did not produce quite as much grain and straw as the plot which had received no manure for two years in succession.

But the wheat was of better quality, weighing 1 lb. more per bushel than the other. Still it is sufficiently evident that superphosphate of lime did no good so far as increasing the growth was concerned, either the first year it was applied, or the year following.

The carbonate of ammonia was dissolved in water and sprinkled over the growing wheat at three different times during the spring. You see this manure, which contains no _mineral_ matter at all, gives an increase of nearly 4 bushels of grain per acre, and an increase of 887 lbs. of straw.

"Wait a moment," said the Deacon, "is not 887 lbs. of straw to 4 bushels of grain an unusually large proportion of straw to grain? I have heard you say that 100 lbs. of straw to each bushel of wheat is about the average. And according to this experiment, the carbonate of ammonia produced over 200 lbs. of straw to a bushel of grain. How do you account for this."

"It is a general rule," said I, "that the heavier the crop, the greater is the proportion of straw to grain. On the no-manure plot, we have, this year, 118 lbs. of straw to a bushel of dressed grain. Taking this as the standard, you will find that the _increase_ from manures is proportionally greater in straw than in grain. Thus in the increase of barn-yard manure, this year, we have about 133 lbs. of straw to a bushel of grain. I do not believe there is any manure that will give us a large crop of grain without a still larger crop of straw. There is considerable difference, in this respect, between different varieties of wheat. Still, I like to see a good growth of straw."