MICHIGAN BEET SUGAR IN 1900. 395 



AVERAGE OF THE MOST IMPORTANT ASH MATERIALS IN THE TWENTY-EIGHT SOILS. 



L4ine (Ca O) 1.13 per cent. 



Potash ( Kj O ) 1 . 3(j per ceut. 



Phosphoric acid (Pj O5) 'S'i per cent. 



This tahfe sliows tliat tlu* Michi;;an soils arc ricli in tlie ash materials 

 roquirc'd lor sugar beets. Potash is in special demand for this crop, 

 and these soils are remarkably rich in this chemical. 



THE WATER-HOLDING CAPACITY OF SOILS. 



The relation of the capacity of soils to hold water b}' capillarity to 

 their power to produce crops is coming into prominence, as the result 

 of recent investigations. Prof. Whitney of the Department of Agricul- 

 ture is making extended inquiries in regard to this relation of soil and 

 water in securing the best conditions for the production of special 

 crops. 



The quantity of water which dry soils will thus take up and hold 

 varies with the kind and texture of the soil. If 100 grams of dry quartz 

 sand are poured into a funnel, with a small filter to prevent the sand 

 from running out, and water poured on the sand till completely w^et, and 

 the excess of water allowed to filter off, it will be found that this sand 

 will take up and hold by cai)illary attraction 25 grams of water, or 

 25 per cent of its weight, which is its ''water-cai)acity." If other 

 soils are treated in the same way the}' will take up different percentages 

 of water. A prairie soil on the average took up 62 per cent of water; 

 fine soils from river bottoms, 57 per cent. The less water a soil will 

 absoi'b the more rapidly it will part with it, both by filtration and 

 evaporation. A soil whose water capacity is less than 33 per cent 

 is liable to suffer in dry weather. Some soils by reason of their large 

 water-capacity ma}' carr}' crops successfully through a dry spell where 

 other soils would fail for want of stored moisture. 



In ])ronouncing ujion tlu^ croii-produciiig ability of a soil, its water- 

 cai)acity must be taken into account as one of the conditions of fruit- 

 fulness. Measured by this standard we find the Michigan soils are ver}' 

 satisfactory, as the average watei*-ca])acily of these 28 soils is 47.4 per 

 cent — a good defense against di-outh unless very severe and long 

 continued. 



RAINFALL IN MICHIGAN. 



An adequate? and distributed sui)i)ly of water is an essential condition 

 in agriculture. The average rainfall in central Michigan, as shown by 

 .3(; years' observation at the Agricultural College, is .32 inches; along 

 the shores of the great lakes the rainfall is a little larger. 



AVERA(iE MONTHLY RAINFALL FOR THE SIX GROWING MONTHS. 



May 3.23 inches. 



June 3.50 



•Fiilv 3.23 



August 2.77 



<i: 



')-> 



SejM ember 2.72 '' 



OctolxT 2.44 '' 



