124 EXPERIMENT STATION EECORD. 



Field experiments on the availability of nitrogenous fertilizers, J. G. 

 LiPMAN, A. W. Blair, et al. {'New Jersey Stas. Bui. 260 {1913), pp. 3-33, pis. 

 5). — Supplementing cylinder experiments previously reported upon (E. S. R., 28, 

 p. 725), an attempt was made " to show the relative availability of nitrogeneous 

 fertilizer materials, and the influence of lime on the availability of soil organic 

 matter, by means of field experiments conducted on 1/20-acre plats, with a 

 rotation of corn, oats, wheat, and grass." 



The experiments here reported were made on a fairly heavy loam soil and 

 covered one 5-year rotation (1909-1913). The nitrogeneous fertilizers used 

 (equivalent to 16 lbs. of sodium nitrate per plat) included sodium nitrate, cal- 

 cium nitrate, calcium cyanamid, ammonium sulphate, dried blood, tankage, and 

 dried fish besides horse and cow manure and leguminous and nonleguminous 

 green manures, with a basal fertilizer of acid phosphate and potassium chlorid. 

 One series of plats received 1 ton per acre of ground limestone at the beginning 

 of the rotation; the other was unlimed. 



Analyses of the soil at the beginning and end of the rotation " indicate that 

 the plats have lost in total nitrogen, even those which have each year received 

 heavy applications of manure and commercial nitrogeneous fertilizers. The 

 limed plats have lost nitrogen to a greater extent than the unlimed plats. . . . 

 All plats are now distinctly acid, requiring from 1,000 to 2,200 lbs of lime (CaO) 

 per 2,000,000 lbs. of soil to correct the acidity. The present lime requirement 

 of the plats which were limed in the beginning is, on an average, about 700 lbs. 

 per acre less than that of the unlimed plats." 



Volunteer clover was more abundant and richer in nitrogen on the limed 

 plats, as was the yield of dry matter and the percentage of nitrogen recovered, 

 in nearly all cases in the first crop after liming but not thereafter. 



" The percentage of nitrogen in the dry matter was generally highest on those 

 plats that received the heaviest application of nitrogen, as, for example, those 

 that received both manure and nitrate of soda. The average percentage of 

 nitrogen in the dry matter was practically the same on the limed and unlimed 

 plats. 



" The average percentage of nitrogen recovered for the first crop was more 

 than twice as high on the limed as on the unlimed plats. For the succeeding 

 crops the average recovery did not differ much on the two sections. The highest 

 average recovery for the five years, unlimed, was 49.99 per cent, with ammonium 

 sulphate, and the next highest, 43.98 per cent, with nitrate of soda. The highest 

 average recovery for the limed plats was 55.76 per cent, with calcium nitrate, 

 and the next highest, 47.93 per cent, with ammonium sulphate. 



"The average recoveries with the nitrates, ammonium sulphate, and calcium 

 cyanamid were distinctly higher than with an equivalent amount of nitrogen 

 in the form of dried blood, fish, and tankage. 



"Although the largest yields of dry matter were obtained from plats receiving 

 manure and manure with nitrate of soda, the recoveries from these plats were 

 lower than the recoveries from plats that received dried blood, fish, and con- 

 centrated tankage. They are likewise lower than the recoveries from plats that 

 received their nitrogen in the form of green alfalfa. The plats receiving green 

 alfalfa and nitrate of soda have given higher yields of dry matter and higher 

 recoveries of nitrogen than plats receiving blood, fish, and tankage." 



In general " results point to a higher availability, and a higher percentage 

 recovery, for nitrogen in the form of calcium and sodium nitrate, ammonium 

 sulphate, and calcium cyanamid than for nitrogen in the form of dried blood, 

 fish, and concentrated tankage." 



