240 Bulletin 247. 



goes without saying that large amounts of nitrogen cannot be laid up 

 m plants without the plant having the power to secure it from some 

 source. Is it not the plain inference that legumes which require large 

 amounts of nitrogen in a short space of time, could not acquire this 

 nitrogen without nitrogen-gathering bacteria because the soil ordinarily 

 does not have sufficient nitrogen available at the right time? If all soils 

 contain sufficient plant-food for the support of plants, why do legumes 

 bear nodules? 



(2) What docs lime do? 



At the Cornell Station in the spring of 1905, certain plats were sown 

 to alfalfa, portions of which were limed and portions left unlimed. It 

 was found in this instance as in similar experiments, that when Dunkirk 

 clay loam was limed, alfalfa grew much more vigorously than when it 

 was not limed. (See Cornell Bui. 237.) Bizzell determined the water- 

 soluble NO3, P, K and Ca at intervals throughout the season. No marked 

 differences were found in the water-soluble phosphoric acid or the potash, 

 although slight differences were found, but marked and unmistakable 

 differences in the water-soluble nitrogen were found. Bizzell found as 

 an average of 16 determinations at each of three dates, July 20, August 

 21 and September 22, 65.9 parts of NO., in the limed portion and 33.5 

 parts in the unlimed portion, almost exactly twice the amount on the limed 

 as compared with the unlimed portion. This difference was found not- 

 withstanding the fact that the alfalfa, on account of its greater growth, 

 had required more nitrogen. 



Lipman raises the question whether the lime had been the cause of 

 the increase in water-soluble nitrogen and thereby increased the growth 

 of the alfalfa, or whether the lime had exercised in some way a beneficial 

 influence upon the nodule bacteria which were the cause of the increased 

 growth of the alfalfa. He states that he has demonstrated that proteid 

 nitrogen can be excreted into the soil by legumes, although he has not 

 demonstrated that it is soluble. He contends, therefore, that it is possible 

 that the increased growth of alfalfa may have been the cause of the 

 greater quantity of water-soluble nitrogen instead of the result of it. In 

 the spring of 1906, therefore, plats were sown to alfalfa, to timothy and 

 to alfalfa and timothy, and one-third of each was limed, one-third 

 received nitrate of soda at the rate of 320 pounds of nitrogen to the acre 

 and one-third was left untreated. Assuming the nitrate of soda to be- 

 come distributed in 2,000,000 pounds of dry soil this would be an appli- 

 cation of 117 parts of NO3 per million of dry soil. 



The idea was that if the amount of water-soluble nitrogen was 

 increased by liming through an increased nitrification of organic matter, 



