GARDEN MANURES. 



465 



(this was the favourite —the result of former work) ; other mixtures 

 followed. After the Potatos were planted and covered in, the plot was 

 roughly divided lengthwise into a number of parts and ammonium 

 sulphate spread broadcast over one part, i.e. across the furrows. The 

 adjoining strip had nitrate of soda similarly applied after the Potatos 

 were up. The reasons for these differences will be apparent to all 

 students of the principles of horticulture. 



The ordinary gardener cannot compound manures to such an extent 

 as is desirable because he has not the technical knowledge. He may 

 make serious mistakes in mixing, but if done on a small scale as advised he 

 will soon ascertain what he can do. We knew a man who, having heard 

 basic slag recommended as a source of phosphoric acid and knowing 

 something of sulphate of ammonia, thought to make a good manure by 

 mixing these two. The fumes of ammonia gave evidence, when too late, 

 of the mistake made. Technical advice should be sought when obtain- 

 able, bict not relied upo7i until proved by experiment to be sound. A 

 manure mixture is almost certain to do some good, because some one or 

 other of the ingredients is wanted. 



A single ingredient will usually do most good if judiciously applied, 

 but may be practically valueless otherwise. We may profitably consider 

 the ingredients largely used in proprietary manures : — Superphosphate, 

 bone meal, nitrate of soda, ammonium- sulphate, and other less valuable 

 ingredients. Of these, nitrate is immediately available, and the phosphate 

 of the superphosphate is precipitated and available almost at once. While 

 these are being taken up, the ammonium sulphate is being altered from 

 the unavailable to the available, and in turn the nitrogen and phosphate 

 of|the bone meal or other organic manure will become available, the nitro- 

 gen here having to be changed into ammoniacal compounds, prior to the 

 final changes to nitrate. A point of some interest may be mentioned here. 

 Nitrates and chlorides, being very soluble and diffusible, pass wherever the 

 water containing them goes. Not so the phosphates and potash : these 

 are quickly absorbed by the soil from the solution, and, in general, the 

 plant roots have to travel to these ingredients. This shows that it is desir- 

 able, when practicable, to mix only w^hen needed in order that we may vary 

 the ingredients. Moreover, the season influences the requirements to a 

 large extent. 



Potatos, Turnips, and such-like crops, which grow chiefly in the 

 autumn and which receive much intercultivation, do not need an applica- 

 tion of nitrate as much as they would at any other season, because, the 

 soil being warm and w^ell aerated, the conditions are very favourable to 

 nitrification. If these crops grew in early spring, when the winter's rain 

 had washed out the nitrates and the coldness of the soil arrested to a 

 large extent nitrification, an application of available nitrate would be 

 beneficial : this is observable in early spring cabbage. A very small 

 quantity of nitrate forces a fine green tender growth which is very liable 

 to injury. On the other hand, mineral manures, other than nitrates, 

 usually give good results when applied to autumn crops which are M ell 

 intercultivated. Different soils, varying largely even on the same holding, 

 different systems of tillage, and many other matters influence the amount 

 of each ingredient of plant food available for the time being capable of 



