1917] 



FIELD CROPS. 



133 



it was found that on an area of 46.3 acres the average Wayne County farmer 

 produced annually crops valued at $764, while on an area of 40 acres of rep- 

 resentative soil at Wooster the value of the same crops had amounted to 

 $1,251 per annum. The additional expenditures for fertilizers, lime, and labor 

 are estimated at $197, which is thus returned with a dividend of $287, or 140 

 per cent. 



It is concluded that by reducing the acreage in crops and concentrating time 

 and energy on a smaller area of the best land, two-thirds of the area now cul- 

 tivated in the county might be made to produce all that is now grown within 

 the county, and at a saving in laljor which would more than pay for the ferti- 

 lizers required. 



The residual effect of fertilizers and manure, C. E. Thorne {Mo. Bui. Ohio 

 Sta., 2 {1911), No. 2, pp. 48-50). — Supplementing a report previously noted 

 (E. S. R., 36, p. 829), average results obtained in crop-rotation experiments 

 extending over a period of 23 years show that from one-third to one-half the 

 total effect of fertilizers and manure is carried forward to the crops following 

 the one receiving the treatment. The results are summarized in the following 

 table : 



Residual effect of fertilisers and manure. 



The effect of soluble nitrogenous salts on nodule formation, E. B. Feed 

 and E. J. Geaul {Jour. Amer. Soc. Agron., 8 {1916), No. 5, pp. 316-328) .—This 

 paper gives the results of some investigations of soluble nitrogenous salts and 

 their effect on nodule formation. The plan of the experimental work included 

 the following points of investigation: (1) The effect of ammonium nitrate on 

 nodule formation in sand, (2) the effect of calcium nitrate on nodule formation 

 in a mixture of soil and sand, (3) the effect of sodium nitrate and ammonium 

 sulphate on alfalfa and crimson clover in Miami silt loam, and (4) the effect 

 of accumulated nitrates in various soils on nodule formation. 

 ' From the data secured it seems evident that under field conditions nitrates 

 rarely, if ever, occur in amounts sufficient to proliibit nodule formation. It is 

 probable, however, that the percentage gain of nitrogen in legumes is injured 

 by the presence of soluble nitrogen. The nitrogen assimilating power of legumes 

 in the presence of soluble salts appears to depend upon many factors, such as 

 the physical, chemical, and biological composition of the soil, species of 

 plant, etc. An abundant moisture supply may be beneficial to nodule formation 

 in two ways, (1) water is necessary for the normal function of the plant and 

 bacteria, and (2) water tends to leach out the soluble nitrogen. As a general 

 conclusion it may be said that, in order to secure a maximum growth as well 



