Show big quantity of humus in soil most desirable one of tte the important explanations of the desirability of having a quan city of humus or decomposing organic matter in the soil Is found in the capacity of humus for soaking up and storing water which Is thus thua made available later for use by growing plants experiments have revealed that pound sand can hold only 25 pounds of water and pounds pound of clay soil can hold only half its weight in water in contrast pounds of organic matter may hold as much ns as ISO ino pounds or nearly twice its weight of water most soils are mixtures in varying proportions of sand clay silt and organic material As a rule the greater the proportion of organic matter contal contained ned in the soil the greater its water absorptive ca opacity and the greater reserves of moisture it will retain for resistance rest to drouthey and hot weather |