16 



Composition of WeedB, Corn. I^Ullet. Soy B&ans. and 

 Cowpea B. 



Cameron (Bu, Soils, 28, ) observes, that different 

 crops and evun the same crop under slightly varying condi- 

 tions remove not only widely different amounts, but widely 



it 

 different proportions of tainerai constituents from the soil. 



n 

 Snyder (Soils and Fertilizers, 194) states that, the 



sdount of fertility removed in we^Jds is usually greater 



than that in agricultural plants because the weeds ftave a 



t) 

 greater pov.er of obtaining food from the soil. Again, 



• 

 the same author (Minn. Bui. 101, 244) says that, "weeds 



have large amounts of v/ater and proteids. There is more 



protein in dry matter of purseiane, pig weed, lambs quarter, 



cheese weed, i^nd catnip, then in either alfalfa or clover. 



The drain on land by these weeds is because of the nitrogen 



they contain. 



The Florida, West Virginia, and Minnesota Stations 

 have made numerous analyses of weeds. Table IX > showing 

 data on the coapositioa of weeds as well as analysis, of some 

 agricultural plants for comparison, is ag follows j 



