1917] SOILS FEKTILIZERS. 813 



When nitrogen was added in tlie form of cottonseed meal, tliere was vigorous 

 formation of ammonia and nitrate In tlie presence of paraffin, but these disap- 

 peared so rapidly that " it is impossible to say whether such formation was 

 equally as rapid as in the absence of paraffin." In no case did the quantity of 

 ammonia or nitrate nitrogen, where Parowax or paraffin had been added, ap- 

 proach the quantity in the controls at the end of two weeks. The inhibitory 

 effect of the paraffin oil was more marked than that of other forms of paraffin 

 during the early stages of incubation. The effect of the oil appears to be quite 

 largely an inhibition of formation rather than a disappearance of ammonia and 

 nitrate nitrogen. 



" When ammonium sulphate was added to the soil either with or without 

 calcium carbonate, all three forms of paraffin exerted a very marked effect upon 

 the accumulation of nitrate nitrogen. The decreased accumulation of nitrate 

 nitrogen was not so evident during the early stages of incubation except with 

 paraffin oil. With the oil the effect again seems to be to retard nitrification, 

 the quantity of active nitrogen [NOg+NHs] approaching very closely that in 

 the controls. Parowax and paraffin, however, not only decrease the accumu- 

 lation of nitrate nitrogen but also bring about a large reduction in the quantity 

 of active nitrogen. The reduction in active nitrogen occasioned by the various 

 forms of paraffin is not nearly so rapid where ammonium sulphate was added 

 as where nitrogen in the form of cottonseed meal was added." 



Further experiments with larger amounts of soil in paraffined 2-gal. earthen- 

 ware containers showed that " no ordinary sized container used for cultural 

 purposes can be protected with a coating of paraffin, as in these experiments, 

 without the available nitrogen content throughout the whole mass of soil 

 being affected." 



Nitrates and nitrification in relation to cultural practices and plant 

 growth, H. A. NoYES (Abs. Bad., 1 (1917), No. 1, pp. 38, 39). — A summary is 

 given of the first two years' results of soil bacteriological investigations which 

 are being conducted in an experimental orchard where different cultural prac- 

 tices are under direct comparison. The objects of these investigations are 

 first, to find out if the behavior of the trees can be directly correlated with 

 the activities of the bacteria in the soil, and second, to determine the effect of 

 the activities of the bacteria on the soil. 



*' The results are as follows : The nitrates in the field correlate with tree 

 growth (circumference gains). The lower nitrate content under field condi- 

 tions does not mean lower nitrate content after incubation. The field nitrates 

 when compared with the nitrates after incubation give the nitrifying efficiency 

 of the organisms under field conditions." It is concluded that "knowledge of 

 the nitrate content of field soil may throw more light on the activities of nitrify- 

 ing bacteria than the nitrification test itself." 



A program of soil improvement for New York State, E. O. Fippin {N. T. 

 State Col. Agr., Cornell Univ. Ext. Bui. 15 (1917), pp. 499-534, figs. 5). — "The 

 purpose of this bulletin is to point out the primary elements of a comprehensive 

 system of soil improvement, and to propose a program of work that will coordi- 

 nate and unify, so far as that is now practicable, the field study of soils." 



Barnyard manure and products of decomposition, H. Mubphy (Okla. Agr., 

 5 (1917), No. 9, pp. 13-16, 18). — This is a brief summary of experience at sev- 

 eral of the State experiment stations and at certain foreign experiment stations. 



Manure from the sea, E. H. Jenkins and J. P. Stbeet (Conn. State Sta. Bui. 

 194 (1917), pp. 3-13, figs. 7).— This bulletin treats of the manurial value of 



