Mat, 1910.] 



444 



Miscellaneous, 



manure. This nitrogen in the form of 

 nitrates is taken up in solution in water 

 by the root-hairs of plants and is used 

 to build up the tissue of which the plant 

 consists, there is no plant not containing 

 nitrogen in some form. To the rule that 

 nitrogen is absorbed as nitrates in 

 solution in the soil moisture, there is an 

 apparent exception in the case of the 

 leguminous plants, Legumes if grown 

 in a soil devoid of nitrogen will yet find 

 nitrogen which other plants would fail 

 to do, the explanation being that on the 

 roots of legumes there are to be noticed 

 small " nodules," which, if examined, 

 will be found to contain micro-organisms 

 or bacteria or germs which take nitrogen 

 from the air between the particles of 

 soil and form nitrates, and these nitrates 

 are then utilized by the plant roots as 

 indicated above. 



Nitrogenous fertilizers are applied to 

 land as nitrates direct, e.g., saltpetre, or 

 nitrogenous organic matter, e.g., decom- 

 posing cowdung, decomposing animal 

 matter, etc. This nitrogenous organic 

 matter is ultimately decomposed by 

 certain germs into nitrates. Before this 

 happens, the nitrogen is useless to plants 

 or is "unavailable." Hence to render 

 fresh farmyard manure, etc., a good 

 fertilizer, it must be applied to land 

 where there aie plenty of the required 

 germs living. Now these germs live 

 preferably in a good open, warm or 

 well-tilled soil, and not in a heavy im- 

 stirred un aerated soil- 



Sulphur— Is taken in by the root-hairs 

 of plants as a soluble sulphate in solution 

 in the soil moistures, e.g., sulphate of 

 ammonia, gypsum or sulphate of lime. 

 Although gypsum is only slightly soluble, 

 in time most of it finds its way into the 

 plants ; it contains the very useful con- 

 stituent lime as well as sulphate. 



Phosphorus.— This essential is taken 

 in by the plant in the condition of 

 soluble phosphate; although it is applied 

 to land in such forms as bone-dust, bone- 

 meal, ground bones, slag, superphos- 

 phate, etc, The phosphorus in bones is 

 absolutely useless as it exists, or, in 

 other words, it is "unavailable"; but 

 when the bones rot as they do in a soil, 

 though slowly, the phosphorus is changed 

 to phosphates which are soluble and can 

 then be taken in as plant food, when it is 

 said to be "available." The finer the bone 

 is ground, the more readily " available" 

 is the phosphorus in it for food. Whole 

 bones take years before being any good 

 as manure, while bone-meal is much 

 quicker in its action. 



Calcium— Is an essential constituent 

 of plants, but a very small quantity is 

 sufficient. The great point about calcium 



(and lime) is that it is a stimulant, its 

 presence in the soil rendering other 

 ingredients such as phosphates, sulphates 

 and nitrogen in organic matter more 

 quickly available to plants. The lime de- 

 composes complex substances with all 

 these nutrient materials as it were 

 locked up in them. The many virtues 

 of lime have been set forth in this 

 Journal, Volume I, No. I of 1907 (vide 

 page 33). 



Potash — Is an essential, and plants 

 rich in starchy or sugary matter, e.g., 

 potatoes, beetroot and fruits are very 

 fond of potash. Wood ashes contain a 

 small amount of potash. 



Magnesium and Iron— Ate also essen- 

 tial, but only in very small quantities, so 

 that all soils practically possess quite 

 sufficient of these. 



Chlorine and Sodium— Are held by 

 some to be essential, but in other respects 

 a similar remark applies as in the case of 

 magnesium and iron above. 



An application of any very soluble 

 manure to land must be given with 

 proper caution; because the very fact ot 

 its being soluble renders it more liable 

 to be washed out of the soil in drainage 

 water during and after heavy rain. 

 Such a soluble and valuable fertilizer 

 as nitrate of soda should be applied 

 when the crop has germinated, and 

 again later on, so that by giving two or 

 three dressings the plant is able to 

 absorb it instead of its being washed 

 away. Where a slower acting nitro- 

 genous manure is required sulphate of 

 ammonia or farmyard manure, etc., is 

 better because it is less soluble and, 

 therefore, less likely to be lost, and the 

 nitrates as they are formed in the soil 

 are mostly absorbed at once on a well 

 cropped area. From the above it is seen 

 that if land rich in nitrogenous material 

 be left fallow, the whole of the nitrogen 

 is " nitrified " or changed into nitrates, 

 and instead of being used by a crop 

 these are washed out ot the soil by 

 heavy rain. 



Superficially it would seem likely that 

 if the average analysis of the plants 

 cropped on a certain area of land was 

 taken together with the analysis of the 

 land, one would be able to get a clear 

 insight into the requirements of that 

 land ; that is, however, not so, since 

 analysis does not indicate how the 

 various elements of plant constituents 

 are existing in the soil, i.e., whether or 

 not they are in an " available" condition. 

 Hence in all cases it is necessary to 

 experiment by applying fertilizers con- 

 taining the different plant foods, and 

 to observe the result in each case both 

 separately and with mixed fertilizers. 



