New York Agricultural Experiment Station. 481 



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above, acid phosphate, sulphate of potash and nitrate of soda were 

 applied equally and in liberal quantities. 



Taking the whole series of experiments into consideration it 

 appears that the soils have been varied from pure sand and manure 

 on the one hand to medium clay loam and manure on the other. 

 A very light sandy loam also has been tried and the texture of 

 the clay loam has been lightened by adding sand in various pro- 

 portions. There is nothing in the results to show that a light 

 sandy soil is essential to securing the best results in forcing head 

 lettuce. In fact, in these tests the best lettuce has been grown on 

 the clay loam where its texture has been loosened by mixing lib- 

 eral quantities of stable manure with the rotted sod. This pro- 

 duces a soil full of " fibre " with a great capability for conserving 

 moisture and with a superabundance of available plant food. 



With 50 per cent of sand added to the clay loam and manure, 

 see Soil 11, Crop IV, the crop was three days later, the heads 

 averaged slightly less in weight, the texture, firmness and general 

 appearance were not so good and the tip-burn decidedly increased. 

 When the texture of the clay loam was loosened by increasing the 

 sand 16 per cent and 26 per cent with Crop I and 32 per cent with 

 Crops II and III, the only noticeable advantage was a very slight 

 tendency to earlier maturity where the larger percentages of sand 

 were used. 



A comparison of the records of the four crops, as set forth in 

 Table 4, might at first give the impression that the different crops 

 do not agree very closely as to their results, but a more careful 

 study will show that in reality they conflict with each other but 

 very little, if at all. With the first crop there was no marked 

 difference in the weight of the lettuce on the different soils. With 

 the second crop the sand and manure, Soil 6, gave decidedly 

 heavier plants than did the soils which contained clay loam, but 

 the latter really gave superior lettuce, for the plants on Soil 6 

 formed rather loose heads, actually less valuable for market than 

 the more compact though somewhat smaller lettuce which was 

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