LIMING ONIONS 



141 



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Figure 1. Graphical Representation of the Relation between Soil Acidity and Growth 



of Onions. 



Color on Soil-Tex pH Values 



Onion Growth 



Deep blue 



Deep blue to 

 light green 



Light green to 

 lemon yeUow 



Orange-yellow 



7. V Neutral 



6.5 ) Slightly acid 



GOOD 



5,5 ) Moderately acid FAIR 



4.5 ) Very acid 



POOR 



Forty-one fields, or about 36 per cent, were found in the acid ramge 

 of pH-.5.1 to 6.0. In tliis group of less acid fields the yields were gener- 

 ally better, 54 per cent being 250 or more bags per acre. But even in 

 this range of soil acidity there were far too many failures. 



Few fields were found showing the more nearly neutral reaction. There 

 were 15 fields with soils pH-6.0 or above in reaction. The yields from 9 of 

 these exceeded 250 bags per acre. 



It is apparent that most of the poor yields of set onions were from 

 very acid soils, and most of the good yields from soils not so acid; and 

 that lack of lime is responsible for many set onion failures. Otiher con- 

 ditions, such as previous crop effects and poor sets, may be blamed in 

 some cases. 



