94 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



CONTRIBUTIONS FROM THE WISLEY LABORATORY. 



XXVI. — The Effect of Manganese Sulphate on the 

 Yield of Turnips at Wisley. 



By F. J. Chittenden, F.L.S. 



During recent years reports of increased yield following the addition 

 of small quantities of manganese sulphate to the soil have been re- 

 ceived, and it was thought desirable to try the effect of this substance 

 on the soil at Wisley. Messrs. Pickles kindly supplied some for the 

 purpose, and the following trial was made. 



We publish the results obtained so as to put them on record without 

 discussing their significance. Salts of manganese are not, as a rule, 

 regarded as materials of which the plant can make use, and the action 

 of manganese in the soil is by no means understood. The results at 

 Wisley suggest the desirability of further investigation, for it seems 

 evident that under certain conditions (at present not definitely known) 

 manganese sulphate may exert a beneficial effect, but at the same 

 time it should be pointed out that in many places a lessened crop has 

 followed its application. It is possible that it acts by promoting 

 certain chemical reactions in the soil, either directly or indirectly, 

 and in that case its effects are likely to vary according to the nature of 

 the chemical constituents of the soil to which it is added. Until its 

 action is better understood it would be premature to recommend its 

 use except on an experimental scale. 



The trial was carried out on the ordinary cultivated soil of the 

 vegetable quarters at Wisley without manuring in 1914, except as 

 set out in the table. There were four plots in the series, and these 

 were in triplicate (twelve plots in all). The plots, each 7 feet 

 6 inches wide and 33 feet long, were set out side by side, and on 

 each, after the addition of the substances mentioned below and 

 suitable cultivation, three rows of ' Early White Stone ' turnip 

 were sown 18 inches apart, an equal weight of seed being sown 

 in each row. The distance from the outer row of one plot to 

 the nearest row on the next was thus 4 feet 6 inches, so that 

 the influence of the treatment of one plot would not be felt by 

 the plants on the next. 



