10 The Bulletin. 



ing plants, thus performing its cycle in plant and animal life. For 

 this reason we need to study the various legumes and increase the acre- 

 age in those adapted to our soils and conditions. 



In addition to adding nitrogen to the soil, being deep rooted plants, 

 they help to deepen and to drain our soils, also to take plant food from 

 the lower depths, where shallow-plant roots could not get it, and bring 

 that to the surface and leave it there in the leaves, stalks, etc., of the 

 plant where it becomes available for after crops. They also add humus 

 to the soil, thereby adding to the water storage capacity of our soils. 



Humus. 



Most of our soils that have been cultivated for any length of time are 

 deficient in humus. Perhaps it may be truthfully said that the greatest 

 need of our upland soils today is humus. Many of our farmers fail 

 to appreciate its great value. By humus I mean decaying vegetable 

 matter or vegetable mould. It plays a very important part in crop 

 production. It supplies plant food and is also a storehouse or reservoir 

 for moisture to dissolve plant food. (See Fig. 4.) This is very important. 

 Without moisture no land is productive. The most fertile field can 

 produce nothing without moisture to dissolve the plant food which it 



COMPARATIVE 



water Hnr.-omft -ROWFr?^ OF SOILS 



IQO POUN D5 of- each QF the -following 5Q1L5 when 

 SATURATED HFLD -the following amounts of WATEg . 



Fig. 4 



contains. Humus also adds to the availability of the inert plant food 

 in the soil. Decaying vegetable matter produces acids that act on the 

 locked-up potash and other forms of plant food in the soil and makes 

 them available to the growing plant. All soils, even pure sand and clay, 

 contain some plant food, but it may be unavailable to the plant. Humus 

 aids in unlocking this plant food and makes it available. 



