78 The Food of our Agricultural Crops. 
set apart for that purpose did not fail so quickly, or from the 
same causes, as the experiments with red clover, still the result 
of thirty-two years' experience with beans established the fact 
that, under no condition of manuring could what might be 
called good agricultural crops be obtained year after year. It 
may be said that my land is not what farmers would call " bean- 
land ; " still, it is heavy, with a clay subsoil, and at first it grew 
good crops. The land, however, appeared to get " tired " of the 
crop, and after thirty-two years' trial we considered that nothing 
more could be learnt by a continuation of this experiment. We 
therefore decided to sow the field with barley and red clover, 
having previously sampled and analysed the soil of the various 
plots with great care. Speaking generally, the soil had lost a 
good deal of its original fertility, and both the top soil and sub- 
soil were especially poor in nitric acid ; agriculturally, the field 
might be said to have been " run out," and to have no condition 
left in it. The clover, which was sown with the barley, was so 
luxuriant that the growth of the latter was greatly impeded. The 
leaf was remarkable for its beauty, and had a colour which I had 
never before noticed in any ordinary field of clover. It was mown 
for hay the two following years, and yielded very luxuriant crops. 
Upon some portions of this field no manure of any sort had been 
applied from the commencement of the experiments in 1848, and 
in some years the beans would not return much more than the 
seed sown ; and yet upon this same land very large crops of 
clover were grown, estimated to have removed 281 lb. of nitrogen 
per acre, while at the same time the nitrogen in the top soil 
had largely increased. Altogether, between the crop and the soil, 
something like 500 lb. of nitrogen are estimated to have been 
obtained from some source or other. 
In 1848, some acres of land were set apart for experiments 
upon a rotation of crops. Part of this land has been kept 
entirely without manure, another part has received a mineral 
manure, and a third part has been highly manured with minerals, 
salts of ammonia, and rape-cake. The ordinary four-course 
rotation of turnips, barley, clover, and wheat, has been followed 
upon one-half of the experiment ; and upon the other half t he same 
crops have been grown, only excluding the leguminous crop, 
instead of which, a summer fallow has been taken, one of the 
main objects of these experiments being to ascertain the influence 
of a leguminous crop upon the other crops in a rotation as com- 
pared with a fallow. As it was found impossible to make the" 
clover crop grow every fourth year, beans were substituted 
for it. Although we are now in the middle of the eleventh 
rotation, we are not yet able to give the information we 
