of experiments on widely different soils show that it p^J or 

 nearly always responds profitably to an application of — 

 about 200 pounds of salt per acre. This guides us to l6 s 

 the choice of kainit for this crop, as that product con- 

 tains about 35 per cent, of chloride of soda, or common 

 salt, which also aids in conserving the moisture in the 

 soil. Good judgment must be used, however, as the 

 kainit might have a harmful effect in a wet season on a 

 low and naturally damp soil. 



About 400 pounds of kainit per acre should be used, 

 as a rule. It should be drilled into the entire surface 

 of the ground early in the spring to a depth of at least 

 three inches, for the kainit becomes fixed in the soil 

 very quickly and should be rather deep, so as not to 

 attract the feeding roots too near the surface. In case 

 wood ashes or muriate of potash are used, the- time of 

 making the application should be the same. Most 

 vegetables will give greatly increased returns from the 

 use of chemicals if lime is employed in conjunction with 

 them. 



An application of 75 bushels per acre of ground 

 quicklime has also proved preventive of onion smut. 



If the soil is a medium heavy clay upland and not 

 acid it is best to use the acid phosphate which contains, 

 besides the phosphoric acid, about 50 per cent, of cal- 

 cium sulphate (gypsum). This unlocks the natural 

 potash in the soil. 



The quantity of either to apply on ordinary soils is 

 1,000 pounds per acre very early in the spring, so that 

 in preparing the ground it will become very thoroughly 

 incorporated with the soil before the onion seed is 

 sown. 



The following table gives the actual field results 

 of six years' experiments with fertilizers and seven years 

 with manures at the rate of 30 tons per acre: 



Manure. Chemicals. 



Tons per acre, average 8 . 90 14 . 02 



Market value per ton, average. . $18 . 16 $20 . 52 



The crop grown with chemical fertilizers was 5.12 

 tons greater per acre, or a gain over the stable manure 

 of nearly 58 per cent.; while the Nitrate crop averaged 



