FIELD CROPS. 635 



_tbaiL would be. lost by evaporation from a free water surface of equal area. 

 The presence of a sufficiency of soluble phosphates helps to reduce the trans- 

 piration ratio, and this makes the crop more economical of water, 



"A 15-acre block of lucern yielded 6.5 tons of commercial hay during the 

 second season of growth, and 4.3 tons during the third season, though receiving 

 only three irrigations during the past season. Tamworth lucern has given the 

 best average yield during the past two years, averaging 22i cwt. per acre for 

 ten cuts. The heaviest seedings of lucern gave the best returns, but there 

 appears to be no material benefit in sowing more than 18 lbs. of seed per acre. 

 Sixteen lbs. is the seeding adopted at Werribee. 



" The application of artificial fertilizers gave decided and profitable increases 

 over the unmauured plats. Nitrogenous manures, though not generally used to 

 fertilize leguminous crops, gave the most marked crop increa.ses. Superphos- 

 phate proved to be the most efficient of the artificial phosphates. An application 

 of 2 cwt. at seeding, costing 9s., gave an increase of a ton of lucern hay to 

 the acre in the second season of growth, and this in spite of the dryness of the 

 season. Lime has given an increase in crop yields, but the increase was barely 

 sufficient to cover the cost of the application. Heavier dressings than 20 cwt. 

 appear to depress the yield. The effect of these manures will probably be felt 

 next season. Lime has given greater crop increases than an equivalent value 

 of ground limestone, though the effect of the latter manure may be expected to 

 persist longer. In view of the heavy demands made on the mineral constituents 

 of the soil by good lucern crops, top-dressings, applied every winter, of phos- 

 phates at the rate of 1^ to 2 cwt. per acre are recommended. On soils similar 

 to Werribee dressings of lime or ground limestone applied every two years at 

 the rate of 10 to 12 cwt. lime and 20 to 25 cwt. ground limestone are likely 

 to prove profitable." 



Alfalfa, G. W. Carver (Alabama Tuskcgee Sta. Bui. 29 (1915), pp. 1-7).— 

 This bulletin notes the great value of alfalfa as a hay and forage crop as indi- 

 cated by tests from 1912 to 1915, and gives directions for its production. 



Sug'g'estions to alfalfa growers, A. Atkinson and M. L. Wilson (Montana 

 8ta. Circ. 49 (1915), pp. 9-42, figs. SI). — In this circular are discussed the types 

 of alfalfa, methods of production of hay and seed under irrigated and dry- 

 land conditions, and the value of alfalfa as a pasture crop. 



Studies on bean breeding. — I, Standard types of yellow eye beans, R, Peabl 

 and F. M. Surface (Maine Sta. Bui. 239 (1915), pp. 161-176, pis. 6).— It is 

 here stated that observations have shown that the bean, usually a self-fertilized 

 plant, may be cross-pollinated by the action of the large bumblebee, so that 

 for breeding purposes it has been found necessary to erect bean cages inclosed 

 with screen wire. The commercial importance of the Maine bean crop and of 

 the two types of yellow eye beans are discussed. Standards of types, including 

 the characters of sizes and shape, ground color, and eye pattern and color, are 

 suggested for the Improved Yellow Eye and the Old Fashioned Yellow Eye, 

 followed by comments of leading Boston dealers. 



Seed values of maize kernels, butts, middles, and tips, Mary G. Lacy (Jour. 

 Amer. Soc. Agron., 7 (1915), No. Jf, pp. 159-171). — This article reviews the 

 work of experimenters along this line with a view to determining how far the 

 apparently contradictory results of different experiments could be reconciled 

 by taking into account the fact that the silks of the kernels from the tip end of 

 the ear are the last to appear, and hence are more likely to escape self-fertiliza- 

 tion than other kernels. 



The experiments from which these data are compiled cover a period of 45 years, 

 and show that " the average yield of seed from the butt is 103 per cent of that 



