- 122 - 



plats the soluble nitrogen lowered much more rapi^dly 

 than did the moisture. While the moisture soon ran so 

 low in these plats as to limit plant growth it is a ques- 

 tion whether the poverty in nitrogen was not equally, 

 or even more, the limiting factor. Can the plant, by 

 lowering its content of this constituent continue growth 

 if moisture is available? That this can be done is 

 indicated by the nitrogen of the corn fodder on plat 5 

 being only .84^, while this constituent in the corn fod- 

 der of three other plats determined v/as nearly double 

 this amovint . Had the moisture and nitrates of the soil 

 been equally limiting factors we would expect the content 

 of this constituent to be about the same as in the other 



piats . 



In the other plats of the north series during 

 the drought (see column Aug. 19 & 26) a great variation 

 was noted even |n the checks (plats 1, 4, 7, 10, & 15). 

 Plat 7 is notably low. Plat 1 has a moderate amoimt . 

 This is the heaviest soil of this eeries. Diffusion be- 

 ing hindered in consequence, what is the limiting 8.mount 

 for growth of corn or for checking the accia^ulation of 

 nitrogen by the plant? Plat 2 (scraped) is high in 

 nitrates. Plat 16, which is a check in the ^J^^^^^^ _, 

 is the highest in nitrate content of any unfertilized plat^. 



Plats 14, 15, and 17 fertilized with a heavy 

 application of sodium nitrate, failed, at least, to give 



