92 Manuring of Crops in Rotations. [may, 



had considerable effects as far as the fourth and fifth following 

 crops. The increases in value in the crops of one rotation were 

 very considerable from both dung and artificials applied during 

 the first rotation. 



While these trials show such good after effects from manuring, 

 they emphasize the need of the regular application of manures, 

 and they indicate that crops benefit greatly from the residue of 

 manure applied many years previously, as well as from direct 

 manuring. In other words, good farming means an accumula- 

 tion of soil fertility. Further, if this good farming is not con- 

 tinued the soil will, after a time, produce smaller crops, and 

 these cannot be increased immediately to the normal by heavy 

 direct manuring, but only after a continuation of liberal manur- 

 ing for some years. 



From the averages of the results it is evident that about half 

 of the increases in value are obtained by the root crop, taking 

 into account the delay of two or more years in obtaining the 

 increases in values of the later crops. When, however, the roots 

 are eaten off on the land by sheep, especially if cake is also fed 

 to the sheep, the manurial value of these foods should be added 

 to the value of the residue of the manure applied for the roots. 

 On the lighter and more hungry soils an even greater proportian 

 of the increase in value is likely to be returned by the root crop. 



The remaining half of the increases in values are fairly well 

 distributed over the remaining crops of the rotation^ and become 

 gradually reduced. At one centre, however, the gains up to the 

 fifth crop were remarkably high. 



There is no advantage, but the reverse, from distributing the 

 manures over all the crops, and in addition to this, the cost of 

 this method of application is very much greater. The extent to 

 which any small distribution may take place is indicated in the 

 suggestions for manuring given below. 



When artificials only are used a potash manure is essential 

 on light soils and may be useful on heavier soils, but v/hen dung 

 is used in addition the potash manure may not be required. 

 Baeic slag is often more profitable than superphosphate oh 

 arable land. When swedes are fed off with sheep receiving 

 cake it may be advisable on good soils to take two white crops 

 before sowing down with seeds. 



