Gardening for Amateurs 



Manures and Manuring 



367 



IX modern gardening the soil may be re- 

 garded as a medium for the passing of 

 nutritive elements into the plant. It is 

 true that the soil supplies certain ingre- 

 dients necessary for the existence of vegeta- 

 tion, but in the main these are added by 

 zardeners to the ground in the form of 

 manure ; were it not so, our soil would be 

 depreciating year after year ; hence it is 

 necessary to regulate manuring by the 

 demands of the crop. 



Elements Necessary for Plant Food. 

 The ingredients of nutrition necessary 

 for vegetation form a small list of some ten 

 elements hydrogen, oxygen, carbon, nitro- 

 gen, sulphur, phosphorus, potash, lime, 

 magnesia, and iron ; a few others may be 

 found in the ash of plants, such as soda 

 and silica, but the ten mentioned are abso- 

 lutely essential for successful development. 

 Hydrogen and oxygen are taken into the 

 plant as water, which is a compound of these 

 two gases. Carbon, curious to tell, is 

 absorbed as carbon dioxide or carbonic acid 

 gas through the pores in the leaves ; it is 

 never taken up by the roots. Sulphur in 

 the pure state is useless as a manure, but 

 the sulphates in soils and in manures supply 

 the little that is required. 



Lime we have already spoken about ; a 

 small amount enters into the composition of 

 the plant. Magnesia is important for all 

 vegetable tissues, and the want of it is 

 shown by the plant turning sickly and 

 yellow when plenty of food exists for it in 

 the soil. It is seldom applied artificially, 

 but if necessary a little sulphate or car- 

 bonate of magnesia may be scattered on 

 the soil ; chrysanthemums require much 

 magnesia. The chlorophyll or green colour- 

 ing matter of the leaves of all plants is a 

 compound of iron ; this chlorophyll cap- 

 tures the energy of the sunbeams, and uses 

 it to manufacture the manurial substances 

 into food. There is plenty of iron in soils, 

 but as this may not always be in a suitable 

 state for the plant J oz. of sulphate or 

 nitrate of iron may be dressed on every 

 square yard of soil. When a plant is 



yellowish, but otherwise healthy, iron is 

 required. 



We are left now with the three elements 

 phosphorus, potash, and nitrogen. Quan- 

 tities of these elements in some form or 

 other are always necessary for the soil, 

 and when manures are spoken of com- 

 pounds of these substances are generally 

 meant. An ideal plant food will contain 

 the three and such of the other elements 

 mentioned as are not present in the soil. 



ORGANIC MANURES 



It is naturally to be expected that decay- 

 ing vegetation should supply the actual 

 requirements of further plants. This is 

 really the case, but before these constitu- 

 ents become available again many changes 

 have to take place. The vegetable matter 

 becomes humus in the soil ; this humus is 

 acted on by the myriads of bacteria until 

 eventually it is decomposed into plant 

 foods. In decomposing, heat is given off ; 

 the ground is kept porous, and gradually 

 enriched by the products. Humus is neces- 

 sary for fertility ; in fact, it is the very 

 essence of fertility. It is long in decaying, 

 hence it keeps the soil fertile and rich as 

 long as it is present, rendering the harsh 

 and barren constituents of the ground into 

 a rich, warm medium for roots to form and 

 increase. The chief organic manures are 

 farmyard manure from poultry and animals, 

 decaying vegetation, and refuse from various 

 sources. 



Farmyard Manure. This consists of 

 the solid and liquid excreta from animals 

 and poultry, intermixed with straw and 

 litter. Sometimes it contains sawdust and 

 shavings ; in such a case it should be 

 avoided, for the wood encourages fungi, 

 which prey more or less upon the plants 

 in the soil. The liquid part of the manure is 

 by far the richer, and the wash and urine 

 should always l>e saved as it flows from 

 the manure heap. Always shelter manure 

 from rain to prevent the soluble plant 

 foods in it being washed away. Old manure 

 is much richer than the new, for the in- 



