Table III. Gypsum or Land Plaster. 



Note: The product carried 18.67% of water. The small amount of calcium and magnesium 

 carbonates present would to a slight extent neutralize sour soils: the calcium sulfate would not be 

 effective for this purpose. 



Deciding the Lime Requirements of the Soil and the Purchase 

 of Lime Products. 



In securing information as to the amount of lime needed on any particular 

 soil for a given crop, the common practice is to call in the County Agent or the 

 Extension Agronomist, who draws the sample, preferably by means of a soil 

 auger, and makes the test. Oftentimes, however, inquiry is made by the farmer 

 as to how he shall proceed in securing a representative sample of his soil for 

 testing. Assuming that a five-acre tract is to be sampled; have at least ten 

 different samples drawn from the area, each sample to be about uniform in 

 weight. Select the places to be sampled so that two of them will be located on 

 each acre and so that the ten places will, so far as possible, be a fair representation 

 of the whole area. Remove all vegetable matter from the surface to be sampled. 

 It is immaterial what tools are employed in taking the sample: it may be a soil 

 auger, trowel or shovel. Each sample should represent a thin section from the 

 top down as deep as one would naturally plow. When a sufficient number of 

 samples have been drawn and placed in a pail or other container, thoroughly 

 mix the whole lot, breaking up the large lumps and continuing the mixing until 

 a thoroughly uniform mass is secured. Fill a clean quart jar with the mixture, 

 taking small portions from the whole area of the mixed mass. Take the sample 

 to the County Agent, Extension Agronomist, or anyone who has the proper equip- 

 ment and experience to make the test and who can advise as to the lime applica- 

 tion necessary for the crop to be grown. 



In purchasing lime in large quantities it is good practice to ask for quotations 

 from several firms, basis f.o.b. at the farm in case truck delivery is most econom- 

 ical, if not, then f.o.b. at railroad station nearest to the farm. In cases where 

 indications of magnesium deficiencies in the soil have been noted through a lack 

 of green coloring matter in the leaves, or a whitening of the leafy structure of 

 plants, a lime product high in magnesium oxide should be selected. As previous 

 lime bulletins have furnished examples for calculating the most economical 

 lime product to buy, further information along this line seems unnecessary at 

 this time. 



Publication of this Document Approved bv the Commission on Administration and Finance 

 2,500— 2-'35. No. 3589. 



