PRESIDEXT ? ADDRESS. 3 



following the breaking up of virgin soil which after a few yeai's 

 has failed to come up to the standard of production of those early 

 years, and in some instances those crops have fallen into neglect 

 or been totally abandoned. Farmers must realise that plant life 

 requires just as much food as animal life. Plant life requires air, 

 light, water, favourable temperature and certain other chemical 

 elements. I say other, because in air itself there are provided 

 already two important chemical elements, namely, carbonic acid 

 and nitrogen, upon which the plant lives. Many farmers consider, 

 however, that the first four of the necessaries I have just mentioned 

 are the only essentials for the growing of crops and that as long as 

 nature provides these elements there is no necessity to consider 

 anything else. It is to the other side of the question to which I 

 specially want to draw your attention this evening, and I wish to 

 show if possible how absolutely necessary it is for farmers to realise 

 that there are other things beside air, light, water and a favourable 

 temperature which must be provided in order to make farming 

 a success, and that with that object in view they must have a 

 rudimentary knowledge at least of the various chemical substances 

 which it is necessary to provide plant life with, and if the^e sub- 

 stances are lacking in the soil itself, either in its virgin condition 

 or if removed by years of cultivation, they must be put back by 

 some artificial means, so as to bring up the soil to its former capacity 

 of production and even to increase that production. 



All fertile soils contain inorganic and organic matter. The 

 inorganic matter in soil is to be found in the grains of rock brought 

 down after changes had taken place in the original and larger 

 rocks by their weathering. Some of these grains are soluble in 

 water, whilst others are not. 



Organic matter, on the other hand, is the residue of plants which 

 have grown previously on the soil, which in some cases may still 

 be in the earlier stages of decomposition and may still be recognis- 

 able, whilst in other cases the remains of plant life may be so far 

 deca^/ed as to have lost all form and to appear simply as a coating 

 a'round the soil grains. 



Soils naturally vary considerably in their texture either because 

 the original plant life has been luxuriant or the reverse, and there 

 consequently is a large or small percentage of organic matter, or 

 because the action of water at one time or another has washed 

 away some of the more soluble parts both of the original rock or 

 the remains of vegetation or has deposited these soluble parts in 

 some new situation. 



\'irgin soil for farming must contain phosphorus, potash, calcium 

 and magnesium, and for the growing of most crops nitrogen. I 

 wish to lay special stress upon the latter fact because in the growing 

 of what are called leguminous plants, such as beans, peas, clovers, 

 etc., these particular plants absorb nitrogen in large quantities 

 from the air and do not depend entirely upon the nitrogen in the 

 soil. The foregoing chemicals, with the addition of carbonic acid, 

 which all plants assimilate from the air. are absolutely necessary 

 for plant life. The chemicals in the soil must, however, be dis- 

 tributed throughout it in such a form and in such quantities that 



