200 THE ESSENTIALS OF AGRICULTURE 



growth of spring is largely exhausted by the second growth in 

 late summer and early fall, and close grazing at this time will 

 hinder the plant from storing food for the next spring's growth. 

 However, after the leaves have been formed in the fall, and have 

 had time to gather and store food, there is no reason why the 

 pasture may not be grazed closely. Indeed, under most circum- 

 stances, close grazing late in the fall is good practice. 



251. Renewing blue-grass pastures. When pastures become 

 very weedy, plowing and reseeding is the most effective remedy. 

 The land is usually cultivated one season in corn, followed by 

 oats, and then seeded to grass. Experience has shown that 

 grass may be revived and reestablished by a liberal dressing of 

 barnyard manure in August or early September, or by the 

 application of a fertilizer containing 3 or 4 per cent of readily 

 available nitrogen (preferably in the form of nitrate of soda or 

 some organic form like dried blood or cottonseed meal) and from 

 6 to 8 per cent of available phosphoric acid. To plow up the 

 pasture and, without manure, grow two or three exhaustive crops 

 will unfit rather than fit the land for the production of grass. 



252. Keep the pastures clean. Many farm pastures are over- 

 run with weeds and brush, and there is little room left in which 

 grass may grow. The most common weeds are the iron weed, 

 the ragweed, thistles, docks, and horse nettles. To this list of 

 weeds may be added two other plants, buck brush and hazel 

 brush, which in some regions occupy much space in the pastures 

 and are serious pests. Mowing twice a year for two or three 

 seasons, and annually thereafter, and close grazing are about 

 the only practical ways to destroy buck brush and hazel brush. 

 Persistent cutting just when they are in blossom is the only 

 effective way to hold the weeds in check. 



253. Canada blue grass. Canada blue grass resembles Ken- 

 tucky blue grass. The seed of Canada blue grass is frequently 

 used as an adulterant of Kentucky blue-grass seed. Canada 

 blue grass prefers a limestone soil and thrives wherever Ken- 

 tucky blue grass is found. It is palatable but not productive 

 enough to take the place of Kentucky blue grass. 



