The Relation of Fertilisers to Soil Fertility (Classic Reprint)
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| Hersteller: | Forgotten Books (Guthrie, Frederick Bickell) |
| Stand: | 2015-08-04 03:50:33 |
Produktbeschreibung
Excerpt from The Relation of Fertilisers to Soil Fertility Recent investigations have brought to light a host of other causes of infertility, but the idea still persists at the back of many soil analyses, that the determination of the amount of certain specified plant-foods, dissolved by specific solvents from the soil, is a certain guide to the nature of the manuring required. As a matter of fact, neither the chemical composition of the soil nor of the crop affords any certain foundation on which advice as to manuring can be based. A. D. Hall and E. J. Russell, dealing with the results of a soil survey of the south-eastern counties of England, draw, amongst other general conclusions, the following which have special reference to the connection between the composition of the soil and plant: "We are not as yet in a position to deduce the agricultural properties of a soil, either its behaviour under cultivation or its adaptability to particular crops, except in the roughest general fashion." In dealing with a number of typical wheat-soils the authors say, "chemical analysis of these soils revealed no connection between their chemical composition and their suitability for wheats," and the same remark applies no doubt to other crops. They also point out that excess or deficiency of any particular plant-food, such as nitrogen, does not necessarily imply a fertile or infertile soil. Even in the case of calcium carbonate, they show that many soils poorly supplied with this ingredient are not benefited by the application of lime, whereas for other soils examined, containing the same or a greater proportion, liming is essential. They find that, "other things being equal, dry soils are more likely to respond to potassic manuring than others better supplied with water, but no richer in available potash." The same applies to phosphoric acid. "Little, if any, direct connection can be traced between the phosphoric acid and the productiveness." As far as regards the value of soil-analysis, as a basis on which to afford advice as to soil treatment, I have no reason to alter the opinion expressed in a paper on "Soil Analysis," read before this Association at the Brisbane meeting, 1895, wherein the view is expressed that a rational scheme of soil-analysis which shall attempt rather to determine the factors influencing fertility than to elaborate methods for determining the chemical constitution of the soil, can be made of considerable value to the farmer. This statement has been amply borne out by experience, and to day the analysis of farmers soils on the lines then laid down is one of the functions of the Department most regularly availed of by farmers. In spite of all the labour expended for many years on this subject, manuring still remains very largely empirical in its nature. We know, in a broad and general way, that a soil deficient in plant-food is not likely to produce good crops without manuring, and that a soil rich in plant-food is likely to prove a fertile one. But much further than this we cannot go. If a soil is well supplied with, say nitrogen and potash, but poor in phosphates, it by no means follows with any certainty that it will be benefited by phosphatic manuring. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
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