MANURES AND HUMUS IN SOIL. 159 
not see a single plant of fox-tail on a square rod, 
and this over a great part of the field. Just destroy 
the plant absolutely before it seeds during one year 
and you have it conquered. 
Growing Humus-making Crops.—Not every farm- 
er has access to a manure heap. Some have too 
much land, some have too few animals. Thus many 
who wish to grow alfalfa desire to grow on the land 
some crop that will help fill the soil with needed 
humus. What is available for this purpose? Very 
much depends here upon the location. 
Cowpeas.—In Tennessee, and probably in Ken- 
tucky, the cowpea is a good forerunner of alfalfa. 
The cowpea has several excellent qualities. If a 
vigorous growing variety is chosen it covers the soil 
all over and shades it. This shade promotes the 
gathering of nitrogen as we have long known. The 
pea vines smother weeds and so help clean the land. 
Their roots, abundantly supplied with nodules, 
gather nitrogen and store it in the soil. After cow- 
peas the soil is also much more friable than it was 
before. The vines may be left to lay upon the land, 
disking them and turning them under, or may be 
cut off for hay. Certainly one gets more humus to 
turn them under. In the South a crop of cowpeas 
may be grown and the land plowed and sown to al- 
falfa the same year. This is not practicable north 
of the Ohio River. Morgan found in Tennessee a 
very great increase in alfalfa yield when it was 
sown after cowpeas. 
Turning Under Green Cowpeas.—There seems a 
