FARMERS' INSTITUTES, 167 



tied to an empty manger. Water falling on a fertile soil soaks out the 

 several compounds, and, while the root fibers are sucking up this bill of 

 fare, the process is kept in operation, so long as water in sufficient quan- 

 tity is present for the purpose. It has been quite accurately determined 

 that it requires a little more than 300 pounds of water to produce one 

 pound of dry matter in stalk and grain. Spring crops, that require 

 nearly the whole growing season for maturity, sulBfer for want of rain 

 more than the wheat crop, which gets its strongest growth and root 

 development during the fall and spring, when rain is most abundant. 



According to Prof. King's field experiments at the Wisconsin Experi- 

 ment Station, oats require 500 pounds of water for each pound of dry 

 matter produced, barley 400 pounds, corn 309 pounds. An acre of oats in 

 field produced three tons of grain (seventy bushels) straw and roots, and 

 used 779 tons — equal to seven inches of rainfall. An acre of barley pro- 

 duced two tons of dry matter (40 bushels of grain), and uses 482 tons of 

 water — equal to four and one-third inches of rainfall. An acre of corn 

 averaged four and four-tenths tons of dry matter (66 95-100 bushels of 

 shelled corn), and used 1,492 tons of water — equal to thirteen and one- 

 half inches of rainfall. 



It has been shown that a grass plant, in a dry hot day, will lose by 

 evaporation an amount of water equal to its own weight. Ordinary 

 meadow grass is about 70 per cent water, and, estimating the crop of hay 

 at two tons per acre, the weight of the fresh grass, not counting the 

 roots, would be about 6^ tons. This would represent the amount of 

 water evaporated by an acre of grass in a dry hot day, and gives some 

 idea of where a part of the water goes that falls in showers in season- 

 able years. An inch of rainfall on an acre is equal to about 100 tons of 

 water; and if it could all be utilized in the growth of plants, longer 

 periods without rain would be less distressing. 



TOO MUCH WATER VS. TOO LITTLfe. 



A soil saturated with water, and the extreme of dryness, are equally 

 injurious to the growth of plants. The golden mean is about twenty per 

 cent of water — that is twenty pounds of water to every hundred i)ounds 

 of soil. If this proportion can be maintained, with the average tempera- 

 ture of our seasons, maximum crops will be grown. As we have seen, 

 different soils have this power of holding water in different degrees. 

 The more fertile the soil naturally, or a poor soil made fertile by 

 judicious farming, will retain more water and hold it in suspension 

 longer than a thin, porous soil. A soil made open and porous by deep cul- 

 tivation holds more water, which is less liable to evaporate, or be lost by 

 percolation beyond the reach of plants to recover. The problem, there- 

 fore, which presents itself, is how to make available more of the water 

 that falls. 



There is some movement of water in the soil. It spreads itself out 

 laterally, and when the soil is saturated, or nearly so, there is a move- 

 ment upward in an effort to keep the particles of soil equally moist, and 

 may be attributed to diffusion, or capillary action, or both. There have 

 been repeated experiments to determine to what extent this movement 

 helps to raise the water in the soil, to compensate for evaporation, and 



