113 BOARD OF AQRICULTURB. 



The cereal crops when sown in the autumn or spring do not 

 begin actually growing until the middle of April in this country, 

 and they begin to turn yellow and cease to assimilate force in 

 about ninety days. The root crops which are sown about the 

 same time, continue to grow and assimilate force for about twice 

 the period. They are moreover aided by the constant stirring of 

 the soil which they receive throughout this period, fresh matter 

 being constantly oxidated. During this period, too, the rain-fall 

 is hardly suflScient to carry the soluble salts beyond the range of 

 the roots. I think, therefore, these circumstances fully explain 

 why in our experiment, a larger percentage of the supplied nitro- 

 gen is recovered in our root than in our cereal crops, and also 

 why a root crop is more exhausting if removed from a soil, and at 

 the same time more restorative if consumed on the land, than a 

 cereal crop can be. 



Experiments on Sugar Beet, Barn Field, Rothamstead. 



Average produce of 1871, 2, 3, 4, 5. The average produce per 

 acre and the average percentage of sugar are, in all cases, for the 

 five years. The average percentage of dry matter, of mineral 

 matter in the dry matter, of the roots are, in all cases, for the first 

 three years. The percentage of nitrogen relates to the first year 

 only ; but the percentage of nitrogen has been determined in the 

 juice in selected cases each year, and these results confirm the 

 indication of the nitrogen in the roots in the first year. The 

 average percentage of dry matter and mineral matter in the dry 

 matter in the leaves are for the first and second years only. 



