170 MASS. EXPERIMENT STATION BULLETIN 154. 



fodder or corn and reduces the expenditure necessary for con- 

 centrated feeds. 



2. Cultivation of alfalfa greatly improves the soil as a 

 result, chiefly, of the deep penetration of its great tap roots 

 and of the assimilation of atmospheric nitrogen which is left 

 behind in large quantities in roots and stubble. 



3. Alfalfa will thrive on almost all thoroughly drained soils, 

 but the field should have considerable surface slope, and a soil 

 rich in lime is best. 



4. A heavy application of lime is in almost all cases neces- 

 sary, usually from 1^ to 2| tons at least. 



5. On soils which are low in humus and relatively poor, one 

 good application of manure plowed in is beneficial, but in 

 general, fertilizers should be preferred to manure because less 

 likely to bring in weeds, grasses and clovers. 



6. The best source of potash for the crop is sulphate, and 

 one of the best sources of phosphoric acid is basic slag meal. 



7. The Grimm variety is superior. 



8. Among the principal obstacles to success are leaf spot or 

 rust, w^hich can be prevented by cutting when it first appears; 

 dodder, which can be avoided by care in the purchase of 

 seed; the competition of weeds, grasses and clovers, w^hich is 

 reduced by avoiding manures or fertilizers rich in 'nitrogen; 

 and winterkilling, which is due to poor drainage, formation of 

 ice and insufficient growth for protection.^ 



' Since this bulletin was written we have had opportunity to note the condition of alfalfa upon 

 the station and college grounds in the spring of 1914. There is more winterkilling than for many 

 years; and reports received from different correspondents indicate that the winter of 1913-14 ha3 

 destroyed a large portion of the alfalfa in the State. A great deal appears to have been destroyed 

 also in Connecticut. 



The older seedings have in general suffered more than newly seeded areas, but in one case at 

 least, reported by a large grower in Connecticut, the opposite was true. 



The minimum temperature records were not exceptionally low, but from the middle of January 

 until about the end of February the average temperature was low, and when lowest there was 

 little snow protection. The principal known difference in conditions during the winter of 1913-14, 

 and the winters of the recent years during which alfalfa has suffered little injury, was the higher 

 proportion of water in the soil due to heavy autumn and early winter rains. It is the writer's 

 belief that this was an important predisposing cause of injury. Alfalfa will endure extreme coid 

 in relatively dry soils, but in soils containing a large proportion of water such temperatures sub- 

 ject its root system to most unfavorable conditions. 



The Grimm variety has suffered far less than the common, even when the seed from which the 

 latter was started was northern grown. In the light of existing conditions the writer's conviction 

 is strengthened that our farmers will be wise not to depend too exclusively upon this crop. He 

 would particularly urge that even although the seed be considerably higher in price, all farmers 

 undertaking the growth of alfalfa should, for the present, plant Grimm varietj', and as the demand 

 for this seed is heavy and the price high he calls attention to the fact that there will be much 

 temptation to substitute seed not true to name. The utmost care should be taken, therefore, 

 to purchase only from parties known to be reliable. 



