CH. v] Falloivimj 89 



yields per plant, but proved less effective per acre than 

 the ordinary methods. 



Ridging. In the northern counties and in Scotland it 

 is customary to lay the land in ridges on which turnips 

 or swedes are grown. The process is found to be helpful 

 because it facilitates drainage and evaporation; but 

 there is no advantage in doing this in the south, where 

 there is usually too little rather than too much water. 

 Trials made in Essex showed that mangolds grew better 

 on the flat than on ridges^. 



Fallowing, or leaving the ground free of crops, gives 

 the farmer a free hand for his cultivations, and much 

 increases the stock of nitrate in the soil: the growing 

 plant apparently interferes with bacterial activity and 

 reduces the amount of nitrate produced. Thus there is 

 less nitrate present on cropped land than on fallow land 

 even after allowing for what has been taken up by the 

 crop. The following data were obtained at Rothamsted : 



N as nitrate, lbs per acre 



Indeed, wherever the climate allows, it is good prac- 

 tice to plough very early in autumn and cultivate well 

 so as to kill weeds and to give the bacteria a good chance 

 of producing nitrates for a winter-sown crop. This is 

 called a bastard fallow. It may even be profitable to 

 secure an earlier start by sacrificing the aftermath of 



^ Journal Board of Agric. xx. 45. 



