FORTY-FIRST ANNUAL CONVENTION 283 



chief objection to it has always been the expense of the seed. 

 The larger varieties of the field pea require from 3 to 3^ bush- 

 els of seed per acre the average for all varieties being about 2y2 

 bushels. The price of seed v^hich has not been hand picked and 

 is therefore apt to be of mixed varieties varies from $1.50 ltd 

 $2.00 a bushel. This means that the seed alone for a green-ma- 

 nure crop will cost in the neighborhood of $5.00 an acre. Com- 

 mon vetch, on the other hand, on account of its smaller seed, re- 

 quires only 60 pounds of seed to the acre and entails an expense 

 of not more than $2.50 or $3.00 an acre. When used for green 

 manure the peas should not be plowed under until they have 

 reached their maximum growth, unless other conditions connect- 

 ed with the main crop require that the plowing be done earlier/ 

 It is well to remember that the field pea continues to grow lon^^ 

 after the first blooms appear, successive blooms being formed as 

 the stem elongates. The most favorable time to plow the peas 

 under will probably be reached, therefore , about the time the first 

 pods are well filled. 



The varieties selected for use as a green-manure or a cover 

 crop should be those which are known to be adapted to the lo- 

 cality, and one with a good-sized vine is to be preferred overt 

 those that make a heavy yield of seed. The large Mairrowfat 

 peas, such as the Canadian Beauty, Arthur, Paragon, and 

 Mackay, are well adapted for this purpose, as are also the Prus- 

 sian Blue and Wisconsin Blue. 



The use of a green-manure crop is profitable only in sections 

 where sufficient soil moisture is present to cause the quick decay 

 of the vegetable matter turned under. This prerequisite is sup- 

 plied in southern California and other irrigated districts by the 

 irrigation water. The immediate financial loss accompanying 

 the use of green-manure crops in rotation systems which are be- 

 ing tested in the Great Plains region is due largely to the insuf- 

 ficiency of soil moisture and the fact that the green-manure crop 

 often occupies the ground late in the season, using up the supply 

 of moisture which would otherwise be available for the next 

 crop. 



