Farmers of Forty Centuries

Book Excerpt: on when its efficiency in crop production may behighest. South China has a rainfall of some 80 inches with little ofit during the winter, while in our southern states the rainfall isnearer 60 inches with less than one-half of it between June andSeptember. Along a line drawn from Lake Superior through centralTexas the yearly precipitation is about 30 inches but only 16 inchesof this falls during the months May to September; while in theShantung province, China, with an annual rainfall of little morethan 24 inches, 17 of these fall during the months designated andmost of this in July and August. When it is stated that under thebest tillage and with no loss of water through percolation, most ofour agricultural crops require 300 to 600 tons of water for each tonof dry substance brought to maturity, it can be readily understoodthat the right amount of available moisture, coming at the propertime, must be one of the prime factors of a high maintenancecapacity for any soil, and hence that in the Far ERead More