492 STATE BOARD OF AGRICULTURE. 



overcropped in rare instances only. A porus soil is essential, and where a good 

 percentage of vegetable matter is lacking, it can be readily supplied by plowing 

 under clover, field peas or sand vetches early enough during the preceding fall 

 to permit perfect decomposition for early spring planting. 



When all conditions are favorable, the alfalfa plants, during the first and 

 sometimes second season, may nevertheless behave as they have at the Station, 

 i. e assume a sickly appearance as if in need of moisture, and the leaves during 

 midsummer turning more or less yellow and dropping off after a few days of 

 hot, dry weather. Careful observations during several years would seem to point 

 to the conclusion that this condition is due to a lack of moisture, and becomes 

 manifest even during seasons which are too wet for most all other crops. Many 

 plants are known to evaporate during the growing season a weight of water 

 equal to several hundred times their own weight. This should particularly apply 

 to alfalfa, since if cut at the proper time for hay, it will furnish a daily growth 

 of nearly one inch during the entire growing season, the growth of the best plot 

 during the past season having been 50 inches for the first cutting, 36 inches for 

 the second and 25 inches for the third, or 111 inches during the season. The 

 extreme longevity of alfalfa and its readiness to furnish several crops each season, 

 indicate that the plants cannot be damaged by frequent cutting unless when per- 

 haps done too late in the season. Frequent cutting reduces evaporation surface, 

 hence is the proper remedy against the yellowing of the leaves, though in irri- 

 gated districts the trouble may be avoided by timely applications of water and 

 Is probably for this reason, practically unknown in such districts. As for tubercles 

 upon alfalfa roots. It is no doubt true that they are necessary for best results, 

 but it is equally true that satisfactory results have been obtained here without 

 any tubercles, for during the past four years 2 to 8 plants have been dug up 

 each season and no tubercles have as yet been found upon any roots, not even 

 upon the plot of Turkestan alfalfa which was partly inoculated in 1903 with soil 

 obtained from the Michigan Experiment Station. Equally negative results were 

 obtained with two plots planted in the orchard at the same time and with the 

 same seed, these plots being plowed up in 1902 as reported in a former Bulletin 

 and owing to a poor job of plowing, quite a number of plants survived, and some 

 were still found growing late in 1903. Each of these plants when dug up, was 

 found with tubercles upon its roots. Similar results have since been obtained 

 with a plot of sand Lucerne which was plowed up when found to be alfalfa. In 

 shape, the tubercles resembled those found upon the roots of the Sand Vetch, 

 and while some could probably be found upon the roots of some plants on the 

 original plots, if enough were dug up, the prompt action of the bacteria upon 

 all plants disturbed by plowing is nevertheless strange. 



The depth of soil to permanent water will need but secondary consideration 

 except in a few localities where, as at the Station, the soil of terraces bordering 

 the streams may possibly be too shallow. The soil of the alfalfa plots has a depth 

 of 12 to 15 feet to permanent water, and comparative tests will be started upon 

 the shallow soils which average three feet in depth. 



The difference in yield of the several plots is not a question of origin of the 

 seed. It is due in the first place to a difference in the quality of the soil as ex- 

 plained in a former Bulletin, and in the second place to a difference in the vitality 

 of the seed which resulted in a correspondingly good or poor stand. The same 

 amount of seed, or at the rate of 30 lbs. per acre, was used for each plot, but as 

 the seed was not tested before planting, the resulting stand ranges from the best, 

 or about 90 per cent of a perfect stand for the German alfalfa, to the poorest, 

 or about G5 per cent for the Turkestan. It follows that 35 lbs. of seed per acre is 

 not any too much for the purpose of obtaining a perfect stand. 



The yields of the plots are shown in the following table: 



