1847.] Mineral Food of Plants in the Soil. 55 



the mechanical condition of the soil, besides adding important 

 chemical properties. 



The presence ol' these mineral elements is important not only to 

 the amount, but also to the quality of the crop. Grain grown up- 

 on a soil abounding in them in a condition to be rapidly assimila- 

 ted will be of much better quality than that grown upon a soil 

 deHcient in them. Some are disposed to attribute the diseases to 

 which many vegetables are subject to defective properties of the 

 soil in which they are grown. Though there are very few facts 

 of a character to throw light upon this subject, yet it is, to say the 

 least, possible, and the restoration of the deficiency by the use of 

 mineral manures, may be also the restoration of health and vigor 

 to the plants. This subject is worthy of more attention than has 

 been bestowed upon it. 



The growth of plants upon any soil adds every year more or 

 less to the organic matter of that soil. The leaves and the stalks 

 of these plants die and rot upon the ground and are gradually 

 incorporated with it. The roots that die annually in the soil add 

 also to the store of organic matter. The different forms of animal 

 life inhabiting the earth and its surface — also the worms that 

 crawl through the ground serve to increase the amount of this 

 portion of the soil, so that there is no part of the surface of the 

 earth, and especially that which is cultivated, in which organic 

 matters are not constantly accumulating. These sources of orga- 

 nic matter are also in a degree sources of inorganic elements in a 

 form to be easily used by growing plants. But this portion is so 

 small as to be hardly worthy of computation, applied in this way. 

 It is probably never more than 10 to 12 per cent, of the whole 

 amount added, and is quite as small, compaied with the amount 

 taken away. 



It is easy to see and understand the causes which are continu- 

 ally operating to impoverish the soil. Reason teaches us, when 

 we know the constitution of plants, what experience teaches us 

 without this knowledge. Reason ought also to teach us the reme- 

 dy. There are many farmers at the present day, in this country, 

 who act upon the general principle of feeding plants to a great 

 extent. But they are still behind the teachings of true science in 

 the manner of giving that food to their crops. The analysis of 

 soils from land long tilled always shows a deterioiation in some 

 of the inorganic elements. In almost all cases the soil contains a 

 very considerable portion of organic matter. The tiue principle of 

 farming is to make the soil produce what is most profitable to the 

 tiller. He should therefore understand what is required in order 

 to effect this. And it is undoubtedly true that as a general rule, 

 the soil is more deficient in inorganic than in organic elements, 

 and the restoration of them would be the restoration of increased 

 fertility. 



