136 Commercial Gardening 



with coarse weeds would cost twice or three times as much, and would be 

 cheaper but not better broken up by the plough in the first instance. 

 Digging is always better than ploughing, as a greater depth, is obtained, 

 and the soil is broken up into a much finer condition. Consequently it is 

 better ventilated, and its particles are more easily acted upon and rendered 

 fertile by the weather. The analysis of the ash of Potatoes (see Vol. I, 

 p. 109) will give the cultivator some idea as to the foods that are taken 

 out of the soil. To bring the necessary supplies of potash, phosphoric 

 acid, lime, magnesia, &c., into proper, i.e. a soluble, condition gradually, 

 there is only one way, and that is by constant cultivation. 



Manure. Perhaps there has been no crop so experimented upon with 

 manures artificial and natural as the Potato. Hundreds of experiments 

 have been carried out in all parts of the United Kingdom, on the Continent, 

 and in America, and the results have been most bewildering. Manures, 

 applied in accordance with certain formulae, that give apparently good 

 results in one place, are practically useless in another. The cost of these 

 special fertilizers varies from 3 to 7 and 8 per acre often much more 

 than the entire crop would realize without even considering the question 

 of labour, rent, &c. 



The following figures, taken from Leaflet No. 38 of the Department 

 of Agriculture and Technical Instruction for Ireland, will show the highest 

 and lowest results of field experiments with Potatoes in the year 1909: 



MANURIAL EXPERIMENTS ON SEVEN PLOTS 



