12 MASS. EXPERIMENT STATION BULLETIN 417 



harvested, these plots were also grazed rotationally three times each season. 

 The heavy grazing following the removal of a crop of hay so weakened the alfalfa 

 that most of it had disappeared by the beginning of the third season. If grazing 

 had been restricted to one or two light grazings or if a second crop of hay, only, 

 had been taken, alfalfa would undoubtedly have persisted much longer. Under 

 conditions as they exist at Amherst, alfalfa is a better hay plant than a pasture 

 plant. If alfalfa is used for pasture, cutting the first crop for hay and lightly 

 grazing the second crop is probably the most satisfactory system of management. 

 By 1943, the third harvest year, wide variations were evident in the proportion 

 of grass to ladino in the different seeding mixtures. The following grasses had 

 eliminated most of the ladino clover: Tall fescue, orchard grass, and Kentucky 

 bluegrass. Redtop provided strong competition but did not eliminate the clover. 

 The most serious competitor to the ladino clover was Kentucky bluegrass. This 

 grass appeared in all plots during the third season, whether seeded or not, with 

 the exception of those with good stands of orchard grass or tall fescue. There 

 was a greater proportion of bluegrass in the plots which were grazed than in 

 those which were cut for hay and then grazed. Observations in the field together 

 with the results of these experiments indicate rather definitely that it is neither 

 necessary nor even desirable to include Kentucky bluegrass in a pasture seeding 

 mixture except where the rapid establishment of a bluegrass sod is desired. To 

 sow bluegrass with ladino clover merely reduces the effectiveness and shortens 

 the life of the clover. 



Grasses which persisted but which did not crowd out the clover were smooth 

 brome grass (Canadian strain), meadow fescue (Svalof's early), pasture strains 

 of orchard grass S26, S37, and S143, and perennial rye grass (O.A.C. No. I). The 

 smooth brome-ladino mixture continued to be one of the best mixtures in the 

 experiment. It was the most palatable; yields were good, particularly during 

 midsummer, and a satisfactory clover-grass composition was maintained at all 

 times. By the end of the summer about 60 percent of the herbage was clover and 

 40 percent grass. Some bluegrass was present in addition to the smooth brome. 



Timoth}' was the only grass included in the experiment which tended to be 

 suppressed by the ladino clover. After the second grazing period in June, timothy 

 made very little growth until cool weather in the late summer and fall. 



Response of Different Hay and Pasture Seeding Mixtures to Heavy Nitrogen 

 Fertilization. (W. G. Colby.) In the early spring of 1943, nitrate of soda was 

 applied at the rate of 450 pounds per acre to half of each plot in the series with 

 different seeding mixtures. These plots, seeded in the summer of 1940, made 

 it possible to study the effect of liberal nitrogen fertilization on a number of the 

 more important pasture grasses, both In stands made up largely' of grass and also 

 in stands with varying amounts of clover, chiefly ladino. The following results 

 are of interest. 



Rate of Application: For conditions as they existed, 450 pounds of nitrate of 

 soda supplied too much nitrogen for best results. The weather during the spring 

 months, particularly May, was much wetter than usual, so that the growth re- 

 sponse was abnormally large. Serious lodging occurred in man^- of the hay plots, 

 and in several of the pasture jlots feed was produced for a time faster than It 

 could be efficiently utilized. Under the circumstances, It is probable that 50 

 pounds of elemental nitrogen to the acre would have been more satisfactory than 

 75 pounds. Lodging in the hay plots smothered out most of the clover. 



Dry Matter Yields: The first harvest on the pasture plots was made on May 

 27. Increases In yields as a result of nitrogen fertilization varied from no increase 

 in the case of a poor stand of perennial rye grass and ladino clover, to more than 



