62 The Eothamsted Wheat Experiments. 



IV.-INFLUENCE OF CLIMATE ON THE 

 CULTIVATION OF WHEAT. 



Climate and Our Wheat Crops" is a title so suggestive 

 of important agricultural and economic problems, that it is 

 hardly surprising it should have been made the subject of an 

 essay (E. A. S. Journal, 1880), in which Messrs. Lawes and 

 Gilbert sought to trace a connection between the general 

 character of the seasons and the amount of their respective 

 wheat crops. It has been remarked that, so far as climate is 

 concerned, the British Isles are outside the zone favourable 

 to the growth of wheat, and that its successful cultivation is 

 due to the skill of the farmer in contending against adverse 

 meteorological conditions ; that, however, the decline in the 

 wheat area cannot be attributed to any general change for the 

 worse in the characters of the British climate, is proved by 

 the circumstance that, by dividing the 108 years ending with 

 1880, into six periods of eighteen years each, there is even a 

 slight progressive increase of mean temperature from the 

 first to the last of these six periods (Mr. Glaisher). It is to 

 the greatly increased production of wheat in other countries 

 at a lower cost than in our own, and to low rates of transport, 

 by which it is brought into our markets in quantity and 

 at a price much reducing the value of home produce, that the 

 lessened area under the crop is chiefly to be attributed. 



As only about 5 per cent, of the total wheat crop is 

 derived from the soil itself, the remainder coming, directly 

 or indirectly, from the atmosphere ; and as the amount of 

 matter accumulated from either source depends mainly on 

 the quantity, and the relations to one another, of heat and 



