218 EXPERIMENT STATION RECORD. 



Pot culture experiments, 1913, J. A. Voelcker {Jour. Roy. Agi: Sac. Eng- 

 land, 74 (1913), pp. 41I-422, pis. 0). — These included experiments in continua- 

 tion of tliose of previous years (E. S. R, 29, p. 520) on tlie influence of various 

 metallic salts (zinc, copper, manganese, and cerium) on wheat and on the 

 relation of lime to magnesia in soils, as well as experiments with sulphur as a 

 fertilizer and on the effect on tomatoes of adding lithium phosphate and mag- 

 nesia to natural and heated soils. 



From the results of the pot experiments to test the influence of zinc salts 

 it was concluded " that the addition of zinc up to 0.01 per cent will have, on the 

 whole, a stimulating result and produce better tillering, but that above this 

 amount the influence will be one of a toxic nature. In the form of nitrate the 

 metal will be more active than in that of carbonate or of phosphate." 



In studying the influence of copper salts on wheat it was foiuid in pot experi- 

 ments that " when sulphate of copper was used 0.1 per cent of the metal was 

 absolutely destructive of the plant and 0.05 per cent nearly so; 0.02 and 0.01 

 per cent, however, showed stimulating action, more corn and more straw being 

 alike produced. In smaller amounts copper appeared to have no action. With 

 the carbonate the results were much the same, though not quite so strongly 

 marked. . . . With the heavy dressing of copper, as sulphate, the roots went 

 down only li in. into the soil. With 0.05 per cent they were but little better, 

 but with 0.02 per cent there was a great change visible, and an extensive and 

 very flbrous root growth was produced. With 0.01 and lower quantities the root 

 was much like that of the untreated plants. Carbonate of copper gave similar 

 results, though not so marked." 



Manganese and cerium salts are reported to have shown no indication of 

 stimulation or of toxic effect with wheat plants. 



Experiments upon the relation of lime and magnesia in soils showed an in- 

 jurious effect when magnesia predominated, but when lime was in excess no 

 such effect was produced. 



No influence could be detected with mustard, rape, and clover by the applica- 

 tion of flowers of sulphur at the rates of 3, 6, and 12 cwt. per acre as a fertilizer. 



The results of the experiments with tomatoes indicated that lithium phos- 

 phate in amounts of from 0.0025 to 0.005 per cent and magnesia in amounts of 

 from 0.792 to 1.584 per cent were toxic to the plants, the toxic effect being 

 much more decided with tomatoes than with wheat. It was not clear from the 

 results whether the effect of these substances was due to their action upon the 

 bacterial nature of the soil. 



Manurial experiments (Bd. Agr. and Fisheries [London], Misc. Pub. 17 

 {1914), pp. 22). — In this publication directions, originally drawn up in 1903 by 

 the Agricultural Education Association of England, for making simple fertilizer 

 experiments are given. 



The plans include experiments to show the manurial necessities of the soil 

 as well as the fertilizer requirements of meadow land, permanent pasture, rye 

 grass and clover hay, ruta-bagas, mangolds or cabbages, potatoes, wheat, oats, 

 and barley. Directions are also given for the use of lime in the prevention 

 of finger-and-toe disease, and a method of reporting results is outlined. Dupli- 

 cate plats are arranged for each treatment, these duplicates being as widely 

 separate in the plan of experiment as possible. 



The mixing of fertilizers, K. Diem {Meded. Deli-Proefstat. Medan, 8 {1914), 

 No. 4, pp. 112-117, pi. 1). — This article discusses the mixing of fertilizers and 

 shows how to prepare mixtures of a given composition, explaining also what 

 substances may and what should not be combined in a fertilizer mixture. 



The topographic features of the desert basins of the United States with 

 reference to the possible occurrence of potash, E. E. Feee {U. 8. Dept. Agr. 



