THE MANURING OF MARKET-GARDEN CROPS. 



1019 



Winter Lettuces. 



Winter Lettuces were grown for four years — namely, from 1895 to 

 1898 inclusive— on our original plan of experiment. Since 1898 we have 

 included plots more heavily dressed with nitrate of soda, but the heavier 

 dressings have not very materially improved on the already satisfactory 

 results obtained with the more moderate applications. 



It should be mentioned that, as Winter Lettuces are planted out after 

 a crop removed in the summer, we have followed ordinary market-garden 

 practice in not applying another dressing of dung specially for this crop. 



In the following summary of results, therefore, it will be understood 

 that the dung mentioned was applied not directly to the Lettuces, but to 

 the previous crop. 



WINTER LETTUCES, 1895-1901 (Seven Chops). 



Annual manuring per acre 



Annual cost 

 of manure 

 per acre 



Average weight 



of crop per 

 acre per annum 



Average weight 

 per Lettuce 







s. 



(l. 



tons 



cwt. 



oz. 



50 loads (25 tons) London Dung (applied to 















previous crop) 



25 loads (12£ tons) London Dung (applied to 





nil 





13 



3 



1G-4 















previous crop) 





nil 





10 



13 



13-5 



25 loads Dung (to previous crop) ; Lettuces 















dressed with Phosphates (no Potash) and 















2 cwt. Nitrate of Soda .... 



1 



15 



0 



12 



14 



16-2 



Ditto, ditto (with Potash) .... 



2 



5 



0 



12 



17 



16-5 



25 loads Dung (to previous crop) ; Lettuces 















dressed with Phosphates (no Potash) and 















4 cwt. Nitrate of Soda .... 



2 



15 



0 



12 



17 



160 



Ditto, ditto (with Potash) .... 



3 



5 



0 



13 



7 



16-7 



It will be seen that the best average yield has been very nearly 

 reached on the land which was previously treated with the heavier dress- 

 ing of dung. Nevertheless, in nearly every one of the individual crops of 

 the series, some one or other of the other plots gave better results. It 

 has already been shown, in connection with other crops, that such heavy 

 dunging as 50 loads per acre is unprofitable for the main crop to which 

 it is applied ; and, although it appears from these experiments that, if the 

 extravagance of heavy dunging has been committed for the preceding 

 crop, Winter Lettuces following that crop need not be further manured, 

 we ought rather to consider the case in which the most prudent mode of 

 manuring has been previously followed, namely, the application of a light 

 dressing of dung supplemented by chemical fertilisers. On the whole, 

 when this is the case, it would seem on the average that phosphates, 

 potash salts, and 2 cwt. of nitrate of soda per acre have produced the 

 most economical results. Potash, although it has produced little or 

 no effect on Summer Lettuces when grown with dung, has sometimes 

 proved to be useful for Winter Lettuces. 



During the first four years our totally undunged plots, receiving only 

 chemical fertilisers (including 4 cwt. of nitrate of soda per acre) — the 

 records of which are not included in the foregoing table — gave less 



