PROMISING GREEN-MANURE CROPS. 31 
paratively soft and succulent until well matured. The root system 
consists of a strong taproot, with a fairly well-developed fibrous sys- 
tem radiating from this. The roots penetrate quite deeply into ordi- 
nary soils and aid in overcoming ‘‘plow sole.” The taproot, as well 
as the smaller roots, when well inoculated has many large nodules, 
indicating that it is a good nitrogen gatherer. In southern California 
horse beans are usually well inoculated and have many large nodules. 
In northern California, thus far, they have had very few or no nodules 
the first year they have been grown. Consequently, when grown 
without artificial inoculation they amount to but little, although when 
inoculated they succeed quite well. 
Fic. 9.—View in a citrus orchard in southern California, showing horse beans grown as a green-manure crop. 
Although the stems of the horse bean are quite large they decom- 
pose readily when turned under for green manure. In comparison 
with other green-manure crops horse beans make a good growth, but 
in an orchard will not withstand trampling like the vetches. As the 
seeds are large a considerable quantity is required in seeding, unless 
the field is planted in drills more than the ordinary distance apart. As 
the individual plants make a comparatively large growth they will 
stand this method of planting, and if sown in drills 18 or 24 inches 
apart a good yield will be secured. The season for planting is the 
same as that of vetch. 
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