6 Bulletin 103. 
the angle of the teeth is a very satisfactory implement for this 
purpose. 
4. Summer Curture. Fallowing Ground —leaving the land 
without a crop for one or more seasons—was a common practice 
with the ancients. Dr. Roberts in his work on “Fertility of the 
Land/’ says this was a necessity for them. The imperfect tools 
then used made but a small proportion of the plant food in the soil 
available and the demands of the crops grown soon outran the ob¬ 
tainable plant food. Then the only method for renewal was to let 
the soil “weather out” enough plant food, with the decayed vege¬ 
table matter to sustain another crop. Some centuries later the 
French found that “manoeuvering” the land—causing the particles 
of earth to change place by tillage—made it more productive. Ex¬ 
periments now show that summer tillage in our semi-arid lands has 
an added value—it conserves the moisture while it renders more 
plant food available. Good results have been obtained in Eastern 
Washington, Eastern Oregon, Utah and many sections of Colo¬ 
rado from summer culture of the land every other season. It has 
been found that in this way sufficient moisture can be stored from 
the year’s rainfall to mature a crop, in many localities. 
After the snows of winter have melted in the spring, plow the 
ground at least seven to eight inches deep. Level this down with 
the harrow and packer, following this process with a smoothing 
harrow, forming an earth mulch to check evaporation. This mulch 
should not be too fine as the winds of the plains will tend to rift the 
soil, or blow the earth mulch entirely away. If possible, stir the 
surface soil from two to four inches every ten to fifteen days 
throughout the summer. Allow no crust to form after summer 
showers, as this will increase the evaporation of the soil moisture. 
Keep the ground clean—free from weeds. 
If fall grain is to be sown it is advisable to drill in the grain, 
as this insures getting it below the earth mulch which is really a 
dry earth blanket used all summer to hold the moisture in the soil 
below. Get the seed into this moist under-soil where it can have 
the moisture so essential for germination. It is advisable to seed 
fall grain not later than the last week in September in the lower 
altitudes and not later than the first week in September in 
the higher altitudes; better still, the third or last week in August. 
Ground that has been well cultivated for several years will 
produce two crops in succession and can be given summer culture 
the third year. I11 this way it is possible to grow two crops in three 
years. 
If a farmer expects to cultivate 80 acres he should divide it 
into two crop divisions—cropping 40 acres the first year and giv¬ 
ing summer culture to the other 40 acres. This gives him a crop 
