CULTURE OF MAIZE 235 



ci cowpeas betAveen the rows of maize, which practice is recom- 

 mended for poor land. 



308. Intercultural Tillage. — The cultivation of maize during 

 its early development prevents the growth of weeds and stirs the 

 soil. The destruction of the weeds is made necessary by the 

 fact that comparatively few plants are raised per acre and that 

 it takes these plants from four to eight weeks to occupy the soil 

 and shade the ground sufficiently to check the growth of weeds. 

 The small grains quickly occupy the soil and prevent the growth 

 of weeds. The tillage of these cereals has not in most instances 

 been found to increase the yield. (136) This fact, in itself, 

 suggests that killing the weeds is the most important purpose 

 of tillage. 



309. Injury Due to Weeds. — At the New Hampshire Station* 

 on an uncultivated plat on which weeds grew luxuriantly, the 

 yield of grain was 17.1 bushels per acre, while on a plat culti- 

 vated shallow five times, the yield was 79.1 bushels, and when 

 cultivated deep five times it was 69.7 bushels per acre. The 

 injury due to w^eeds may be attributed to three causes ; 



(i) They consume plant food. The plant food removed by 

 the largest possible crop can easily be supplied in fertilizers. 

 As good a crop could not be raised in this way as would be ob- 

 tained if no fertilizer were applied and the land kept free of 

 weeds. Hence, weeds must do something else. 



(2) Weeds shade the ground. They obstruct the sunlight 

 and perhaps keep the soil cooler. The author, however, mulched 

 a plat sixteen days after planting, with sufficient coarse, straviy 

 manure to keep the weeds in subjection, and obtained forty-eight 

 bushels of grain and 5,009 pounds of maize fodder, as compared 

 with fort}-six bushels of grain and 4,686 pounds of fodder when 

 cultivated one to two inches deep, and forty-one bushels of grain 

 and 4,224 pounds of fodder when cultivated four inches deep. 

 Hence, weeds must do something else. 



1 N. H. BuL 71, p. 47. 



