Pounds of nitrate reckoned as nitrate of soda in top 18 ins. of soil per acre. 
The Effect of Climate and Weather on the Soil. 15 
spring and summer. It may be high, if the spring has been 
favourable and the summer dry, or low if the summer is wet. 
The difference is not simply a matter of rainfall, but also of 
the general state of the soil, other factors coming into play 
which we need not now discuss. 
Fig. 4.— Curves showing the way in which nitrates accumulate in the soil in a hot dry 
season, but get washed out in a wet season. 
This initial October stock remains safely locked up if the 
winter is dry, but it may suffer serious loss in a mild wet 
winter. Here are some results that have been obtained at 
Rothamsted. The most favourable year in recent times for 
the summer and autumn accumulation of nitrates was 1911. 
In September, 1911, a piece of land in good heart that had been 
