612 JOUENAL OF THE ROYAL HORTICULTURAL SOCIETY. 



consequently suffered through interference with the water supply; in 

 1910 a piece of land in good condition, manured with farmyard manure 

 some years previously, was used. The area covered by the whole of 

 the six plots in each year had been treated alike ever since the land 

 has been in the Society's possession. 



The plots were, in any year, all of the same size and shape, and 

 were separa^'^d from one another by paths 1 foot wide. The land was 

 dressed before digging with superphosphate and kainit. 



Nitrate of soda was used at the rate of 4 cwt. to the acre, and the 

 other manures were used in such quantities that each plot received the 

 same weight of nitrogen. 



Equal quantities of seed were sown on the plots, turnip being 

 chosen as being most likely to show results easy to estimate. The 

 seed was equally apportioned between the rows, and, when large 

 enough, the plants were thinned to equal distances apart in the rows. 

 In 1908 the seed was sown on June 20, and the crop harvested 

 November 2 ; in 1909 it was sown on July 23, and harvested 

 November 10; in 1910 it was sown on May 2, and harvested July 28. 

 The crop, freed from soil, was weighed as it was lifted, the tops and 

 roots being weighed separately. 



Table I. shows the yield in each of the three years from each of the 

 different plots. It will be seen that the plots varied somewhat from 

 year to year. 



TABLE I. 



Yield of Turnips from variously Manured Plots. 



Manure applied 



1908 



1909 



1910 



Eoots 



Tops 



Total 



Roots 



Tops 



Total 



Eoots 



Tops 



Total 







lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



Nothing . 



91 



38 



129 



25 



14| 



39| 



82i 



77 



159i 



Nothing . 















75 



81f 



156f 



Calcium cyanamide 



123 



50 



173 



26i- 



19i 



46 



9H 



95i 



187 



Hydrated calcium 



















cyanamide . 









25 





39i 



86 



83^ 



169i 



Ammonium sulphate 



102 



50 



152 



41 



24 



65 



96 



98} 



194{ 



Nitrate of lime 









34| 



21 



55i 









Nitrate of soda 



99 



54 



153 



35i 



20t 



56 



921 



122 



214| 



It is evident that with the exception of the hydrated calcium 

 cyanamide each of the manures considerably increased the yield, and 

 it will also be seen that the best comparative total yield was given by 

 a different manure each year: in 1908 by calcium cyanamide, in 1909 

 by ammonium sulphate, and in 1910 by nitrate of soda. This may 

 possibly be due to differences in weather conditions, for the availability 

 of ammonium sulphate and calcium cyanamide depend to a consider- 

 able extent upon chemical changes brought about by bacterial activity, 

 and this is dependent inter alia upon moisture and temperature condi- 

 tions in the soil. 



If we attempt to eliminate the weather influence by adding the 

 crops for tlie tliree years (wliich we ni;iy do considering the conditions 



