THE MANURING OF MARKET-GARDEN CEOPS. 



1037 



increase of nitrate of soda having, in the case of this large or coarse 

 variety of rhubarb, been productive up to 4 cwt. per acre. And it will be 

 noticed that even chemical fertilisers alone, including 4 cwt. of nitrate of 

 soda per acre, produced very nearly as good results as those obtained by 

 the very heavy dressing of dung without the aid of chemical fertilisers. 



An examination of the results obtained in individual years shows that, 

 on the whole, potash exercised a beneficial influence on the crop in the 

 case of the small varieties. In the case of the large variety, however, 

 potash salts, on the whole, do not seem to have produced a useful effect. 

 Probably the larger root development of the plants enables them to seek 

 mineral food at greater depths than can the smaller varieties, and thus 

 enables them, even when no dung is used, to obtain an adequate supply of 

 potash from the natural resources of the soil. 



In the following summary table, therefore, showing briefly the increase 

 obtained and the relative economy of different methods of manuring, we 

 have selected for comparison the plots which did not receive potash : — 



Annual manuring (in addition to 25 loads Dung) 

 per acre 



Cost of 



EXTRA 



manure 

 per acre 



Average increase per acre 

 of Rhubarb (large variety) 

 over and above the yield 

 obtained with 25 loads 

 Dnng per acre only 





£ s. d. 



Sticks 



tons cwt. 



25 extra loads Dung 



5 0 0 



26,870 



11 15 



Phosphates and 1 cwt. Nitrate of Soda 



15 0 



22,770 



10 6 



Phosphates and 2 cwt. Nitrate of Soda 



1 15 0 



17,160 



9 2 



Phosphates and 4 cwt. Nitrate of Soda 



2 15 0 



41,980 



18 3 



Here the figures are so very striking that they require no comment. 



It is important, however, to add that, both with the large and with 

 the smaller varieties, the great economy of production by the proper use of 

 chemical fertilisers is only one of the features brought out by these 

 experiments. Another great and important feature, which cannot be 

 expressed numerically, is the far better quality of the heavier crops grown 

 rapidly with the aid of a liberal quantity of nitrate of soda, as compared 

 with that of the produce grown with dung alone. This superiority of 

 quality consists mainly — as in the case of Cabbages and other vegetables 

 already referred to — in a far greater degree of tenderness, due to a greater 

 development of soft cellular tissue and a corresponding decrease in tough 

 vascular fibre. The chemically dressed rhubarb, when raw, is far more 

 crisp or tender ; and repeated trials show that it takes less time to cook, 

 and is, when cooked, much more pleasant to eat, than the Rhubarb grown 

 more slowly by the use of dung alone. 



We have made a new plantation of Rhubarb on which our experi- 

 ments will be repeated and continued. 



Potatos. 



We have recorded seven crops of early Potatos and eight crops of late or 

 " main-crop " varieties. The early varieties were, during the four years 

 1895 to 1898 inclusive, ' Windsor Castle ' ; and during the three years 

 1899 to 1901 inclusive, Webber's ' White Beauty.' As late or main-crop 

 Potatos we grew, in 1894, ' Beauty of Hebron ' ; in 1895, ' Magnum 



