8 PRESIDENT S ADDRESS. 



what chemical is short or o\x'rabundant. It would be but waste 

 of time and money to put a manure into the soil which was com- 

 posed jMimarily of one ingredient of which already there was 

 sufficient in the soil, and not to put in the very ingreilient which 

 was missing or in smaller quantities, and which was the one really 

 required. No one can, however, go very far wrong in putting in 

 kraal and stable manure. It contains a little of everything which 

 was originally present in the soil. These manures also improve 

 the jiower of the soil lor retaining moisture and also render many 

 soils more porous, which, as I have already shown, is so very 

 necessarv in many cases. It also gradually gives up its essential 

 elements and thereby its influence extends over some years so that 

 these are available to the plants as they are needed. The rate at 

 which farmyard manure gives up its elements depends upon the 

 access of air to the manure ; this will therefore depend upon the 

 character of the soil and the manner in which it is applied, whether 

 it is simi>ly laid on the top of the ground or whether it is ploughed 

 under. In light, porous soils it is advisable to plough it under 

 as the oxygen in the air can get at the manure and it becomes 

 almost at once a plant food supplier, whilst in heavy clay soil, 

 if the manure is ploughed in, the air cannot get at it so readily 

 and the results are therefore slower. It is therefore advisable in 

 clay soils to spread the manure on the surface of the ground. The 

 chief defect of this manure is that it is comparatively poor in 

 phosphoric acid, the very ingredient which is most required in 

 South African soils. It is exceedingly to be regretted that in 

 South Africa farmyard manure is almost entirely absent on most 

 farms, simply because the majority of farmers do not follow pro- 

 gressive ways, whilst on the few farms where it is found it is only in 

 very limited quantities. I cannot too strongly urge upon 

 agricultural farmers the necessity of keeping some class of live 

 stock and making arrangements for the regular supply of this 

 manure. 



In consequence of the scarcity of farmyard manure and the fact 

 that this kind of fertiliser does lack phosphoric acid, of which there 

 is already too short a supply in our soils, it is necessary that arti- 

 ficial manures should be used. 



There are many artificial fertilisers on the market so designed as 

 to supply one or more of those chemicals which I have so often 

 named — nitrogen, phosphoric acid, potash and lime. As a rule 

 the best are phosphoric acid and potash fertilisers which, applied 

 broadcast in the autumn and worked into the soil, give very good 

 results. Should these fertilisers be in the shape of bone dust or 

 raw mineral phosphates, it must be remembered that in this form 

 certain further chemical changes have to take place before they 

 become available as a plant food, and therefore they should be 

 given time. Those which supply nitrogen, and nitrate of soda 

 and sulphate of ammonia, or phosphoric acid as superphosphate, 

 all being easily soluble, should be applied to the soil in the spring 

 and worked into the ground when preparing it for seeding. The 

 best form in which to apply lime is — white slaked applied at the 

 rate of at least 300 lbs. to the acre. Wood ashes provide potash 



