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ORGANIC AGRICULTURAL CHEMISTRY 



Nitrogen Cycle 



by nodule bacteria 

 N — — • > Plant protein 



In the atmosphere 



electrically _ -r^^r^ 

 N + O > HNO3 -> KNO3 



In the atmosphere 



Nitric acid Nitrates in the soil 



by plants, as soil food 



KNO3 ^— ^- ^ Plant protein 



with photosynthesized 



Nitrates of soil carbohydrates 



By animals, as food , . , 

 Plant protein : — > Animal protein 



By animal kataboUsm 

 Animal protein — ^ Urea, etc. 



Utilized by some plants 



In soil, by bacteria 

 Urea, etc. and Dead protein — ^ NH^ 



' In sou 



Utilized by some plants 



NH3+O < 



In soil, by oxidizing bacteria 



Into atmosphere 



and returns to 



soil in rain 



(partial) 



Reducing bacteria .^ 

 (partial) 



Into atmosphere 

 and repeats cycle 



KNO3 



Nitrates 

 In soil 

 Repeats 

 cyde 



