THE MONTHLY BULLETIN. 407 



cation of any fertilizers. It -will be noted that this soil contains approxi- 

 mately twice as much sulphur as the sample from the Medford fine 

 sandy loam. Large applications of superphosphate, on part of this 

 'particular field of ]\Iedford clay loam, have produced no increases in 

 yield over the untreated check plots. 



It will be noted that our results from applications of sulphur are con- 

 firmed by chemical analyses of the alfalfa plant, and also by analyses 

 of some of our soils. 



LIME-SULPHUR SPRAY A FERTILIZER. 



The speaker has observed some very striking examples of the effect 

 of lime-sulphur spray on alfalfa, red clover, vetch, and Canadian field 

 peas. The crops when grown under fruit trees which had been sprayed 

 with lime-sulphur were usually larger, more robust, and darker green 

 directly under the tree where the spray drippings had fallen than the 

 plants beyond the spray drippings. This is particularly noticeable on 

 the granite soils. Similar observations have been reported to me by 

 fruit growers at Hood River, Oregon, and in certain sections of Idaho. 

 These fruit growers had attributed this effect to the lime in the lime- 

 sulphur spray. This, however, has often been noted on soils Avhich are 

 normally rich in lime. 



HOW SULPHUR ENTERS THE PLANT. 



The alfalfa plant cannot utilize sulphur as pure sulphur. When sul- 

 phur in the form of flowers of sulphur is added to the soil it must first 

 combine with other elements in the soil, such as calcium, magnesium, 

 potassium, and iron, to form sulphates, before the plant can use it. 

 Possibly the alfalfa plant can also absorb it as sulphites. Sulphur 

 readily combines with lime and forms calcium sulphate, or gypsum, in 

 the soil. This is indeed fortunate for our alfalfa growers, since their 

 soils are usually rich in lime, as well as magnesium, iron, and potassium. 



RECOMMENDATIONS. 



Our w^ork with sulphur, has not been carried on long enough to war- 

 rant any recommendations. We have obtained increases in yield from 

 100 pounds of flowers of sulphur per acre, and usually better results 

 from 300 pounds per acre. We have used iron sulphate with excellent 

 results at the rate of 300 to as high as 840 pounds per acre ; superphos- 

 phate from 300 to 820 pounds per acre ; gypsum from 300 to 590 pounds 

 per acre. Flowers of sulphur will give better results when applied in 

 early winter than late in the spring. 



Heavy applications of sulphur will probably produce a sour soil 

 unless there is plenty of lime in the soil. On soils normall.y sour or low 

 in lime applications of gypsum may be more desirable than flowers of 

 sulphur. For all practical purposes we regard the crude powdered 

 sulphur, analyzing about 98 per cent sulphur, as just as satisfactory as 

 the flowers of sulphur, and it is considerably cheaper. 



Applications of sulphur or gypsum alone will probably not give satis- 

 factory results for any length of time on soils poor in either potassium, 

 magnesium, phosphorous, or lime. 



