FIELD CEOPS. 339 



bulletin describes experiments conducted at the Fort Hays substation in cooper- 

 ation with the Bureau of Plant Industry of this Department. 



Meteorological data show the monthly precipitation for a period of 46 years 

 aggregating 22.98 in. per annum, while evaporation that took place from a free- 

 water surface during the growing season for a period of seven years (1907 to 

 1913, inclusive) averaged 49.344 in. Other data show the moisture conditions 

 of the soil and the crop yields for each season (1910 to 1913, inclusive) for soil 

 that had been prepared for wheat by late fall plowing, early fall plowing, and 

 fallowing. 



The average results for the four years show that the late fall-plowed ground 

 contained 2.7 per cent of available moisture at seeding time, early-fall-plowed 

 ground 4.2 per cent, and summer-fallowed ground 8.8 per cent. The late-fall- 

 plowed ground produced an average of 5.9 bu. of wheat, early-fall-plowed ground 

 11.1 bu., and summer-fallowed ground 21.2 bu. 



As an average of six years, ground subsoiled once in three years and pre- 

 pared each season for wheat by plowing early in the fall has produced an 

 average yield of IS.l bu. an acre, or 3.9 bu. more than ground plowed at the 

 same date but not subsoiled. Alternate cropping and summer fallowing have 

 produced an average yield of 21.3 bu. of wheat an acre, or an average annual 

 yield of 10.6 bu. 



Occurrence of manganese in wheat, W. P. Headden (U. S. Dept. Agr., Jour. 

 Agr. Research, 5 {1915), No. 8, pp. 349-355). — The author briefly reviews the 

 work of other investigators in this field, describes the methods employed in this 

 investigation, which was conducted at the Colorado Station, and gives tabulated 

 data showing the amounts of iron or manganese found in the kernels of wheat 

 samples secured from various parts of the United States, Canada, and Europe. 

 The quantity of manganese found ranged from 0.003 to 0.008 per cent. 



" Manganese seems to be present in wheat wherever grown, irrespective of 

 the conditions of soil and climate. Manganese is present in the wheat kernel 

 in about the same proportion as iron, though iron greatly predominates in soils. 

 Fertilizers applied to the soil did not affect the amount of manganese stored 

 in the kernels. Variation in the quantity of water applied, from 1 to 3 ft., did 

 not affect the amount of manganese in the grain. I do not wish to draw con- 

 clusions from my facts relative to the essential character of manganese as a 

 mineral constituent of plants, though these facts seem to support this view 

 for wheat and possibly for emmer, rye, oats, etc. It seems improbable that a 

 nonessential constituent would occur in all samples and in essentially the same 

 quantity under such a variety of conditions." 



Wheat — barley, P. Symeonides {Cyprus Jour., No. 39 {1915), p. 884)- — This 

 briefly describes a cereal known locally on the Island of Cypress as " Sit- 

 arokrithi." It is considered a hybrid between wheat and barley. 



Quack grass eradication, A. O. Arny {Minnesota Sta. Bui. 151 {1915), pp. 

 82, figs. 26). — In part 1 of this bulletin the author describes the characteristics 

 of quack grass and gives methods employed in two experimental fields in efliorts 

 to eradicate the weed. Part 2 contains tabulated data of the operations on 

 the fields under rotation. The following is a summary of results of several 

 years' work: 



" Quack-grass seed will grow even if the plant is cut before the seed is 

 mature. In order to prevent quack grass from developing seeds to the point 

 where they will germinate, crops in which it is growing should be cut not later 

 than the last week in June. Young quack-grass plants, if attacked before they 

 have formed underground stems, are as easily killed as plants of wheat or 

 other grains of the same age. Manure containing quack-grass seed may be 

 24307°— No. 4—16 4 



