18(3 BOARD OF AGRICULTURE. [Pub. Doc. 



To UTILIZE THE NiTROGEN OF THE SoiL. 



In order for soil nitrogen to be transformed into an avail- 

 able form, the proper kinds of bacteria must be present, and 

 the conditions for their growth must be favorable. 



An abundant supply of oxygen is essential to bacterial 

 growth, and this can be obtained by plowing and the thor- 

 ough working of the soil, particularly during the growing 

 season. 



For the best growth of bacteria the land should be neither 

 dry nor wet. The proper moisture conditions in the case 

 of land not naturally well drained can be improved by arti- 

 ficial drainage. Tile drains are best, and in the end the 

 cheapest. 



Bacteria grow best in w^arm soil. The removal of sur- 

 plus water by drainage, frequent tillage and a roughened 

 surface tend to Avarmth of soil. Dark-colored soil will 

 warm faster in the sun than light-colored ; but, as it cools 

 off faster in the night, dark soil does not Avarm up so much 

 more rapidly as one might at first think. 



If the land is not well stocked with the proper bacteria, 

 the ajjplication of farm manure will usuallj^ give returns far 

 greater than can be measured by the plant food it carries. 

 As has been pointed out, farm manure, either fresh or 

 ripened, is well stocked with bacteria, among which there 

 will always be large numbers of the proper organisms for 

 transformino; the nitroo-en into available form. The addi- 

 tion of manure is often of groat benefit to recently drained 

 swampy land, which will usually be deficient in nitrogen 

 transforming bacteria. 



Bacteria do not work well in the presence of acid ; hence 

 the addition of even a small amount of lime to the field may 

 greatly hasten nitrogen transformation. This explains in 

 many instances the beneficial efiect of applications of lime to 

 recently drained land that was rather Avet before drainage. 



Nitrate nitrogen is very readily lost in a variety of ways 

 from the soil. The surest way to prevent loss is to have 

 plants growing upon the land all of the time during the 

 growing season. The old practice of allowing land to lie 



