A STUDY OF COLORADO WHEAT 
By WM. P. HEADDEN 
PART IV 
Bulletins Nos. 205, 208, 217 and 219 present the work previously 
reported in connection with our study of Colorado wheats. The gen¬ 
eral results in a more popular and less detailed manner have been given 
in Bulletin No. 237. In this bulletin we propose to record our further 
study of the properties of the wheats and flours produced in the course 
of our experiment, together with some flours produced from Colorado 
wheats by various mills in the State. 
CHARACTER OF GRAIN DEPENDS ON RELATIVE SUPPLY OF 
PLANT FOOD 
A brief statement of the concisions reached may be advisable. The 
most important one is that, given conditions under which the plant 
will reach normal maturity, the character of the grain depends upon 
the relative supply of the respective plant foods. 
In our case the important ones are nitrogen and potassium. If 
the latter predomintes, the character of the wheat will be mealy or 
soft, in which case the kernels will be large and plump. If the nitrogen 
present as nitrates be sufficient and in the right proportion to the potas¬ 
sium, the kernels will be flinty and of good size. If the nitrogen pres¬ 
ent as nitrates be excessive the plants will grow too rankly, will be 
susceptible to rust, will lodge, and will produce small flinty, hard and 
shrunken kernels. The crop will be smaller than in cases where less 
nitrogen in this form is present. 
C^rganic or other forms of nitrogen than nitrates or ammonia salts 
whose nitrogen is easily converted into nitrates, is not sufficiently avail¬ 
able to the wheat plant to affect the quality of the crop though it may 
increase the production of both straw and grain. 
Phosphorus in our experiments produced no effects upon the 
yield or character of the grain that we could interpret as directly due 
to the effects of the element. The reason for this is probably that the 
phosphorus present in our soil is sufficiently available to procure a 
maximum effect and the addition of more phosphorus is at the present 
time useless. This condition may change with further cropping. 
There is so near an approach to the desirable ratio between the ni¬ 
tric nitrogen and available potassium in our soil that comparatively small 
