A FERTILIZER EXPERIMENT WITH ASPARAGUS. 239 



less weight in 1911 than in 1910, which is shown clearly by the table. 

 The plots thus affected were Nos. 1 to 10 and 21 to 27. Plots 37 to 40 

 were somewhat affected without showing it in a depressed yield. The 

 yields for 1914 and 1915 showed a nearly complete recovery from the 

 rust. The percentages of increase of the crops for 1914 over those of 

 1910 were determined and the recovery was well shown, except in plots 

 1, 21, 22 and 23, which were most severely affected. The percentages of 

 increase on these plots were, respectively, 51 per cent on plot 1, 57 per 

 cent on plot 21, 59 per cent on plot 22, and 56 per cent on plot 23. On the 

 rest of the plots the majority of percentages of increase ranged between 

 70 and 80 per cent, with a few above 80 per cent, and the recovery from the 

 rust attack on plots 2 to 10 and plots 24 to 29 was evidently thorough. 



The effect of the rust has been considered in comparing the relative 

 effects of different methods of fertilizing the crop, and the yields for the 

 years 1911, 1912 and 1913 have been omitted from the comparisons. 

 The results of the first two years and the last two years are sufficient, 

 however, to give a good view of the effects, since the former serve to 

 show the immediate and the latter the cumulative effects of the fertilizers. 



When the crop yields of the different plots are surveyed as a field it 

 will be noted that plots 11, 12, 13, 31, 32 and 33 jaelded out of proportion 

 to the rest of the field, and from the plan it will be seen that these plots 

 formed a section across the middle of the field. This persistently high 

 jaeld could not have been caused by the fertilizers, but was probably due 

 to a slightly greater depth of soil above the underlying gravel, by which 

 the plants had a slightly greater supply of moisture throughout the season. 



Plots 3, 7, 11 and 34 were fertilized exactly alike with the medium 

 quantities of nitrogen, phosphoric acid and potash. Plots 21 and 13 

 received equal amounts of manure with no chemicals. Plots 1 and 40 

 received medium weights of acid phosphate and muriate of potash without 

 nitrogen. From these plots it can be seen that the western half of the 

 field, including plots 1 to 20, was more productive than the eastern sections, 

 containing plots 21 to 40. The southeastern corner, plots 34 to 40, was 

 the poorest part of the field, all things considered, which may have been 

 due to the slightly coarser character of the soil, as mentioned with the 

 analyses. 



Plot 11 has produced the biggest weight of stalks every year, although 

 by no means the most heavily fertilized. 



Asparagus is considered to be a hearty feeder, and to require an abun- 

 dance of plant food to produce profitable results. Three groups of plots 

 were planned to compare graduated amounts of chemical fertilizers. 

 These plots were Nos. 1 to 12. Table II shows the jdelds. This section 

 was attacked by rust, as already described, but plot 1 alone failed to 

 recover completely from its effects by the year of maximum production, 

 1914. It is clearly demonstrated that the maximum amounts of ferti- 

 lizer were of no appreciable effect, and that the medium quantities were 

 ample for a full yield. The actual need of the medium amount of nitrate 



