396 STATE BOAED OF AGRICULTURE. 



grow upon it in the absence of water. So controlling is its inflnence that the 

 Bible often speaks of an unfailing supply of water as the leading condition of 

 vegetable growtli. " And he sliall be like a tree planted by the rivers of water, 

 and bringeth forth his fruit in his season ; his leaf also shall not wither ; what- 

 soever he doeth shall prosper." The *' Great Sahara" is a desert not from any 

 peculiarity of the soil but mainly from want of water. This imperative ueed 

 of water to sustain vegetable life is not confined to tropical regions, but is felt 

 through every zone of cultivation. Even where water is present in sufficient 

 quantity to sustain life we find that fruitfulness is increased by abundant and 

 well distributed rains. A dry year means short crops in temperate climates 

 fiwdi famine in tropical climes. 



The relations of the Avater of the soil to the ])roduction of crops may be con- 

 sidered under three heads : 1, The amount and distribution of rain ; 2, Capac- 

 ity of the soil to retain water; 3, The approach of the water line to the surface 

 of the soil. 



1. liawfall. — If we could obtain reliable statistics of the amount of rainfall 

 in these new counties, and of the distribution of the rain through the months 

 of the year, they would furnish one very valuable means of determining their 

 agricultural capabilities ; but such statistics are almost entirely wanting. 



2. Capacity to hold water. — The power of soils to take up and retain moisture 

 bears an imjiortant relation to their fertility, because this capacity to imbibe 

 and hold water is one very important condition of their withstanding the in- 

 fluence of prolonged absence of rain. Soils differ greatly from each other in 

 this respect; in the same district and under the same conditions in regard to 

 rainfall we find that one soil will withstand the influence of dry weather and 

 keep its crops green and vigorous, while the crops on a neighboring soil will be 

 parched and burned under the same conditions of weather. 



The capacity of a soil to hold water is influenced both by its chemical composi- 

 tion and by the fineness of its division. Ilumus, or the vegetable matter of the 

 soil, will retain the most water. Clay and the oxide of iron found in soils stand 

 uext, while sand stands lowest in the list. The more finely a soil is divided the 

 more water it will hold ; one hundred parts of carbonate of lime in the form 

 of sand will only hold twenty-nine parts of water, but in the form of fine 

 powder will hold eighty-five parts, or nearly three times as much as the coarse 

 material. 



I have examined these Michigan soils with reference to their capacity to hold 

 water, regarding this as one very important criterion by which to pronounce 

 upon their agricultural capabilities. I thus aim to make the soils tell tlieir own 

 story, while I merely act as interpreter in this respect. The soils were dried 

 at 212 degrees Fahrenheit till they ceased to lose weight; all stones and roots 

 were picked out and all Inmps broken down, but the soils were not pulverized or 

 reduced to a finer state of division than was found in their natural state. One 

 hundred grammes of the soil Avere weighed out, placed in a tared glass funnel, 

 and water poured over the soil till it was completely wet, but the soil was not 

 stirred or puddled in the least ; it was allowed to stand till tlie water ceased to 

 drop, when the weight was again determined ; the increase in weight showed 

 the amount of water one hundred parts of thoroughly air-dry soil would take 

 up and hold. Thissliows tlie relative capacity of these soils to take up and hold 

 under natural conditions the water whicli falls upon them in tlic form of rain 

 or snow, and thus shows their relative resources against periods of impending 

 drought. For purposes of comparison I include in this list soil from ''the 



