The Wohurn Pot-Culture Experiments, 1910-11-12. 383 



again later for comparison with those of 1910 and 1911. Suffice 

 it ni'^antinie to repeat that the results of the first year were not 

 marked by any increase of corn from the addition of lime, 

 though there was a slight increase in straw. 



2. Experiment of 1910. 



It was decided to continue the experiment in 1910, the soil 

 being turned out of the pots and aerated, but no further lime 

 being added. An artificial dressing of superphosphate, sulphate 

 of potash and sulphate of ammonia was, however, given in 

 order to make up for the corn crop already removed. Wheat 

 (" Square Head's Master ") was sown November 15, 1909. It 

 was noticed that the period of incubation was increased with 

 the heavier applications of lime, but eventually all the plants 

 came iip, though there were 17 days' difference between the 

 coming up of the full number of the " untreated " plants and 

 the full number of those that had the heaviest lime dressing. 

 At first the "untreated" plants came on much the quickest, 

 and they were soonest in ear, but then gradually the limed lots 

 gained, and were, moreover, distinguislied by a deeper colour 

 and increased size of flag. They also had much increased water 

 requirements, showing that more rapid growth and trarspira- 

 tion were going on. The water requirements for the six sets 

 were relatively represented by the following figures : — 100 

 (untreated), 112 (lime 1*25 per cent.), 131 (lime 1*50 per cent.), 

 168 (lime 1-75 per cent.), 187 (lime 2 per cent.), 212 (lime 2-25 

 per cent.). 



It was found (in contrast to 1909) that the straw was longer 

 where lime had been applied, also the length of the ears was 

 increased. At harvesting, the produce both of corn and of 

 straw w^as shown to have been increased very materially with 

 the addition of lime. The grain from the limed lots was also 

 more glutinous than that from the untreated. 



3. Experiment of 1911. 

 In 1911 the experiment was repeated, no further additions 

 of lime being made, but the artificial manuring being given 

 again as in 1910. Wheat ("Square Head's Master") was sown 

 on November 9, 1910. It is important to bear in mind that the 

 soil now used was the very same that had been employed for 

 the crops Ijotli of 1909 and 1910, only the one addition of lime 

 (at starting) being made. As in 1910, the " untreated " plants 

 appeared considerably before the lime-treated ones, and until 

 the end of April they were well ahead of the others. The 

 " limed " lots, however, showed the characteristic broad and 

 green flag that had been noticed before, and by the end of May 

 they had practically caught up the " untreated." The " un- 

 treated," as before, showed at first the greatest length of straw. 



