626 EXPERIMENT STATION RECORD. 



under of leguminous crops was found to be the cheapest means of supplying 

 grains and other nonleguminous crops with nitrogen. 



Experiments with untreated rock phosphate in comparison with acid phos- 

 phate indicate that the untreated phosphate is " a cheap and effective source 

 of phosphorus where immediate returns are not required. . . . For quicli re- 

 turns, acid phosphate or some other readily avaihible form should be used." 

 In these experiments heavy applications of rock and acid phosphate still 

 showed marked results after three years. 



Similar results were secured with applications of potash, and the con- 

 clusion is therefore drawn that there is little danger of serious loss by leach- 

 ing of either phosphorus or potassium on ordinary Indiana soils. " Nitrogen 

 on the other hand is readily washed out and should not be applied much in 

 excess of what can be takencare of by the immediate crop." 



No injurious effect on the soil was observed from the continued use of acid 

 l>hosphate. General recommendations regarding the maintenance of fertility 

 of southern Indiana soils and specific directions for fertilizing wheat, corn, iuid 

 potatoes are gl\en. 



Plant nutrition studies, E. li. Voorukks and J. G. Lipman (Xcir Jcrncj/ Sfus. 

 Rpt. 1 006, pp- 101-115). — This is a report of progress in experiments begun in 

 1005 (E. S. R., 18, p. 14), the plan of which is fully described in the abstract of 

 the last report. 



The results obtained to date indicate that the red shale soils used in these 

 experiments are in greater need of phosphoric acid than of nitrogen and pptash. 

 but that while the yield of nonleguminous plants may be materially increased 

 by applications of phosphate alone, the best results will be obtained by using 

 phosphates and nitrogen. " The application of potash will probably prove of 

 some advantage onlj- after an abundance of phosphoric acid aud^nitrogen had 

 been supplied." 



The experiments in the improvement of light soils at Hammonton, especially 

 for the production of forage crops, begun in 1904 indicates that the large areas 

 of such soils now uncultivated and unproductive " may under proper conditions 

 be utilized for dairy purposes to supply local needs, and to furnish, besides, 

 a supply of dairy products for the large centers of population more or less 

 distant." 



Brief accounts are also given of the results obtained with cowpeas in a rota- 

 tion designed for the improvement of soils, and of field ex])erinients with fer- 

 tilizers upon asparagus. 



The predominant role of nitrogen in the productiveness of soils, li. 

 (iRANDEAU {Jour. Agr. Prat., n. scr., I'f {1901), So. 32, pp. 169-171).— The 

 results of 8 years' comparative tests of nitrogenous and nounitrogenous fer- 

 tilizers on a soil of medium quality, somewhat deficient in nitrogen and phos- 

 phoric acid, on which potatoes, rye, colza, wheat, beets, barle.v, maize, and oats 

 were grown in succession are summarized and show that the supply of nitrogen 

 was much more important in increasing the yield than that of phosphoric acid 

 or potash. 



Investigations relative to the use of nitrogenous materials, E. B. Vook- 

 HEES and J. G. Lipman {Sew Jersey 8ta.s. Rpt. 1906, pp. 71-100). — This is a 

 report of progress in investigations which have been going on since 1899 (E. 

 S. R., 18, p. 18). The crop grown in 1906 was wheat and the results obtained 

 in that year are compared with those obtained with the same crop in the regu- 

 lar course of the rotation in 1901. 



Analyses of the different kinds of manure used in these experiments are re- 

 ported as in previous years, attention being called especially to the fact brought 

 out by these analyses that exposure to the leaching action of rain results not 



