FIELD CROPS. 143 



The observations indicate that the most destructive conditions are lack of 

 sufficient snowfall, successive thawing and freezing, and excessive moisture in 

 autumn, especially when followed by dry winters. The capacity to react 

 promptly to stimuli producing dormancy is perhaps the most important quality 

 in producing hardiness in alfalfas and clovers. Variation in the percentage of 

 hard seed accompanies difference in hardiness, but in a way that is not fully 

 understood. Well inoculated plats were uninjured by a frost which had marked 

 effect on slightly inoculated plats. 



Of 68 strains tested during the winter of 1908-9 42 lost 80 per cent or more by 

 winterkilling and 3 lost 10 per cent or less. All European alfalfas lost 79.5 per 

 cent or more, those from Arabia lost 100 per cent, those from Turkestan an 

 average of 72.3 per cent, those from Mongolia 33.5 per cent, those from Canada 

 45.4 per cent, those from Mexico 85 per cent, and those of 18 American strains 

 83.3 per cent, while the hardiest American strain suffered to the extent of 43.7 

 per cent. Grimm seed from Fargo, N. Dak., and Clearwater, Minn., winter- 

 killed only 2.8 and 7 per cent respectively, while Turkestan seed from High- 

 more, S. Dak., winterkilled 9.2 per cent. 



In general the observations recorded indicate that good tillage and suitable 

 strains of seed in favorable winters are the controlling factors in successful 

 alfalfa production on the average fertile Northwest soils. Inoculation deter- 

 mines success or failure. If considerable growth was left on the field in autumn 

 strains of inferior hardiness endured severe conditions, probably because of 

 exhaustion of soil moisture and the protective snow covering held over the 

 crowns by the plants. A thin stand meant high winterkilling save in the hard- 

 iest varieties. The experiments indicate that the most important cause of 

 failure in practice is the use of seed from the wrong regions. The Mongolian 

 alfalfa proved the hardiest newly imported strain, probably because the crowns 

 were the most deeply set in the soil. It is suggested that the long endurance 

 of stands of the Grimm strain may be due in part to its power of putting out 

 new roots after the taproot has been broken. 



The importance of the inoculation of alfalfa on Nebraska upland soils, 

 F. J. Alway (Nchra.si-a Hta. Rid. 1909, pp. 3-20, figs. 2).— The results of 

 investigations elsewhere are summarized with references to the authorities 

 consulted. A discussion of the recognition of inoculated plants is followed by 

 a statement of observations made in alfalfa fields in various coimties in 

 Nebraska. 



Crimson clover culture, A. E. Geantham (Delaware 8ta. Bui. 89, pp. 36, figs. 

 4). — Experiments with fertilizers for crimson clover indicated that acid phos- 

 phate and potash singly or in combination produced marked advantages, but 

 that nitrate of soda did not greatly increase the growth. Suggestions are given 

 for seed production, harvesting, and the detection and removal of weed seed. 



Replies to letters sent out to several hundred Delaware farmers indicated 

 that those replying have grown crimson clover for an average period of 10 

 years, that the average area devoted to the crop was 16.6 acres, that moderately 

 good sandy loam is the predominating soil, and that July and August are the 

 best months and September the latest safe month for sowing. Crimson clover 

 is usually grown after another crop. In 95 per cent of the cases the seed is cov- 

 ered, in 73 per cent not more than 15 lbs. per acre is sown, 80 per cent of 

 spring sowings fail, winterkilling results in a majority of cases, fertilizers 

 are rarely applied at time of sowing in com, liming is successful mainly on 

 clay soils, and acid phosphate and potash are most prominently mentioned as 

 fertilizers. About 83 per cent of those replying on this point cut the crop for 

 hay at or just before full bloom, the average yield of hay being 2.12 tons per 

 acre with an average farm value of $10.60 per ton, while the average seed 



