220 



STATE BOARD OF AGRICULTURE. 



In the following table there is given the grams of dry matter in the leaves 

 stems and roots of inoculated and not inoculated soy beans and in inoculated and 

 not inoculated cowpeas. In the columns following there is given the composition 

 of this dry matter in per cents: 



CONirOSITION OF DRY MATTER. OF LEAVES. STEMS AND ROOTS. 



Soy beans, inoculated. 



Leaves 



Stems 



Routs 



Not inoculated. 



Leaves 



Stems 



Roots 



Cowpeas, inoculated. 



Leaves 



Stems 



Roots 



Not inoculated. 



Leaves 



Stems 



Roots 



Yield 



of nitn.- 



gen per 



acre, llxs. 



113.55 



75.98 



139. 2t 



118.45 



The first column, in the above table, reports the weight of the dry matter of 

 the yields of 12 square feet. The weights are given in grams. Because it is 

 unsafe to calculate acre yields from areas so small as 12 square feet, two adjacent 

 plots of soy beans were harvested at about the date of the taking of these samples 

 for analysis. One of these plots contain .8 of an acre, the other 1.29 acres. The 

 former yielded at the rate of o.j17.(> lbs. of dry substance per acre and the latter 

 4214 lbs. Calculating the yields of dry matter per acre from the figures given 

 in the table above we have 3924 lbs. as the yield per acre of dry matter of the 

 inoculated plot and 3572 lbs. for the uninoculated. These amounts are midway 

 between the actual yield of the larger plots. For this reason it is evidently safe 

 to calculate the yield of nitrogen per acre from the factors given in the table. 

 This has been done and in the last column of the table is found the calculated 

 yield of nitrogen per acre expressed in pounds. The yield of the inoculated soy 

 beans is 113.55 lbs. of nitrogen per acre. These figures include not only the 

 leaves, stems and roots as stated in the table but the nitrogen in the nodules on 

 those roots. Unfortunately the weights of the nodules on the roots of the cow- 

 peas was not taken and the 139.21 lbs. includes no nitrogen resident in the 

 abundant nodules. 



It is interesting to note that the inoculation has increased the amount of 

 nitrogen in the soy beans almost exactly 50 per cent. It is not yet demonstrated 

 that the 37.57 lbs. of nitrogen found in the inoculated soy beans more than in 

 the uninoculated comes entirely from the air through the intervention of the 

 nodules nor is it known that the 37.57 lbs. measures all of the nitrogen taken 

 in by the inhabitants of these nodules. In any event the increased amount of 

 nitrogen returned to the soil by plowing under a crop of inoculated soy beans 

 is amply sufficient to induce every farmer to see that his crop is inoculated if 

 he intends to use it as a soil renovator. 



The fact that the per cent of protein is so much greater in both leaves and 

 stems of inoculated soy beans must lead to the determination to inoculate the 

 crop if it is to be cured as hay. It is worthy of note that in the soy beans the 

 increase in protein is mostly in the true proteids and not in the amids. The 

 inn; Illation docs not seem to notably affect the phosphoric acid nor the potash 



