Huddersfield Soils
By John Grainger

THE CONSTITUENTS OF SOIL

CHEMICAL DIFFERENCES OF SOIL TYPES
A plant makes only a very small part of its solid substance from the constituents from the soil, but that small part is very necessary. It is usual to find that only three chemical constituents are likely to be deficient in soils, namely nitrogen, phosphorous and potassium. All soils contain some percentage of nitrogen, which is obtained from the organic matter, but soils vary in their power to break down the complex form in which the nitrogen exists in undecayed organic matter, into the simpler forms, ammonia and nitrate, which can be used by the plant. There is also a variation in the extent to which nitrogen can be lost from the soil. Nitrogen can be lost in the gaseous form in all soils under special circumstances e.g. water-logging. The nitrogen content of the soil must be regarded as a very changeable quantity, and no general indications short of chemical analyses can be given for estimating the amount at any one time. The cultivator must rely upon subjective indications such as the growth of his plants. Plants which are growing in soil deficient in nitrogen have poor growth of shoot and leaf, and the foliage may have a lighter green appearance than normal. Lack of sufficient phosphorous in the soil tends towards a poor root system, and insufficient potassium induces unequal ripening of fruit and lack of quality in storage organs such as potatoes. Huddersfield soils are almost all short of sufficient potash and phosphorous for growing maximum crops.

Nitrogen, potassium and phosphorous are added to the soil by any natural fertilizer like farmyard manure, poultry manure or sewage manure, and in the form or artificial manures, most of which supply one fertilizing element only:

Further particulars of these manures and their application can be obtained from the author’s Garden Science.

The availability of manures for plant growth is dependent upon the amounts of other substances in the soil, the presence or absence of calcium probably playing the biggest part in this respect. Magnesium and iron are also requisite for the growth of green plants. Calcium, magnesium, sodium, potassium and other elements are often spoken of as ‘soil bases’.

Those elements which will dissolve in water are perhaps the most directly important, and a big difference can be observed between those dissolved out of the Coal Measures and those from the Millstone Grits. The calcium and magnesium compounds particularly make the water hard. The hardness of the main stream in the Meltham Valley on the Millstone Grits is 9° whereas that of the main stream in the Millstone Grits is 16°. Here then is some evidence of the better supply of soil bases from the Coal Measures than from the Millstone Grits. It is interesting to note the large variations which occur in some of the smaller streams. Several of these in the head waters of the Meltham Valley have hardness above 10°, and one even has a hardness of 20°. These streams flow over pockets of thin bands of calcareous material which are known to occur at various places. They are usually beds containing numbers of fossils of marine mollusks, the calcareous shells of which supply calcium.

Ecological indications of the presence of these calcareous pockets are occasionally seen at the surface. One spring in Raikes Dyke before it was covered by the present reservoir had a hardness of 12° and supported a flora of the moss Hypnum commutatum, which is usually found in the waters of limestone districts. Another spring at Drop Clough, Slaithwaite, has a similar hardness and supports a very luxurious mat of the same moss.

Another general indication of the deficiency of soil bases on the Millstone Grits is provided by Comber’s test, where the soil is shaken up with a little potassium thiocyanate in saturated alcoholic solution. This is really a test for iron, which, however, does not come into solution if certain other soil bases are present. It can be made rougher quantitative by judging the depth of the red colour produced, and table 6 gives some results with this test:-

4= Very deficient in soil bases
0= Not deficient in soil bases
Other figures represent roughly quantitative intermediate states.

The following analyses also show the relative deficiency of soil bases in the Millstone Grits as compared with the Coal Measures:

The relatively large amounts of calcium and magnesium sulphates in the Coal Measures water are in marked contrast to the minute amount of magnesium and the absence of calcium from the Millstone Grit, and give additional evidence of the poorer supply of soil bases in the latter.

‘TRACE ELEMENTS’
It has been stated that nitrogen, phosphorous and potassium are likely to be deficient in soils, but modern research has shown that if any one of a large number of chemical elements is completely absent from the soil, growth of several plants will be unsatisfactory. Such chemical elements are only required in extremely small amounts, and are known as ‘trace elements.’ Boron, copper, and nickel and but three examples, and minute traces of gold have even been found in the ash of the common field horsetail, Equisetum sylvaticum. There is not, however, sufficient to tempt any fellow Yorkshireman.

The only evidence of lack of any ‘trace element’ in the Huddersfield district concerns the element boron. Lack of this substance causes a condition of the swede crop known as heart rot. Diffuse brown patches appear in the flesh when the root is cut. It has been controlled successfully by watering with a solution of 1oz. Of borax to 3 gall. Of water when the plants were established.

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