68 



Problems in Potato Growing. 



[may, 



potatoes is concerned. The operation does not appear to be 

 generally deemed necessary for first-earlies, and my own trials 

 on second-earlies in three seasons throw doubt upon its remune- 

 rativeness in a district in which the crop is ripe early in August. 



To cite all the evidence upon which these conclusions are 

 based, derived as it has been from reports of experiments carried 

 out in all divisions of the United Kingdom during a long course 

 of years, would fill the present volume. If it could be given 

 even in summary form, it would fully justify the confidence 

 with which the conclusions are recorded. 



Sub-soiling. — Turning now to problems which, in my opinion, 

 cannot be said to have been solved finally by the results of precise 

 experiments, allusion may first be made to the preparation of the 

 soil for potatoes, in reference to which there is an astonishing 

 lack of distinct evidence. The common practice of good growers, 

 no doubt based on the experience of generations, is that of 

 ploughing deeply in the autumn, cross-ploughing in the early 

 part of the following year, the time being determined by the 

 condition of the soil, and cultivating and harrowing just before 

 planting time, whether the land is to be ridged or not, as it 

 usually is in England and Scotland. So far as noticed, the only 

 writer besides the present one who has recommended sub- 

 soiling for potatoes is Mr. Findlay, the noted raiser of new 

 varieties and a remarkably successful grower on an extensive 

 scale. In his little book on " The Potato : Its History and 

 Culture," he objects to the common impression that, if the 

 land is loosened by cultivation to the depth of six or eight inches, 

 the requirements of the potato plant are met, as it is regarded 

 as a surface-rooting plant. So far from this being all that is 

 necessary, he says, he has found by experience in connection 

 with his experimental plots and by observation where deep 

 cultivation is practised, that the extra yield is out of all propor- 

 tion to the cost of such deep culture. He recommends deep 

 cultivation, not by turning the under soil uppermost, but by 

 subsoiling in the autumn. It may be added that the difference 

 in the crops of last season on adjoining pieces of land, one sub- 

 soiled and the other not so, was astonishingly great in favour 

 of the former. It is strongly to be recommended, therefore, 

 that experiments on various classes of soil should be made 

 with subsoiling. 



