No. 4.] CHEMICAL AND FARM MANURES. 161 



All* slacked or water-slacked lime may be applied to soils 

 at a rate of from one half to two and one-half tons per acre. 

 Upon light, sandy or gravelly soils small applications should 

 be made, while heavier clayey soils, particularly if rich in 

 humus, may be dressed at a greater rate. 



Lime should be spread upon the surface of the ground, 

 and thoroughly harrowed in, preferably shortly before seed- 

 ing or before some crop especially helped by it. Full details 

 regarding lime and its use may be obtained by sending to 

 the United States Department of Agriculture for Farmer's 

 Bulletin No. 77, on " Lime and its use." 



It is possible for the practical farmer to obtain a good idea 

 as to whether his land stands in need of lime. If clover 

 fails to thrive, if beet leaves turn red and many of the plants 

 die or remain small, if onions cannot be successfully grown, 

 if timothy runs out too quickly and if the soil is infested 

 with sorrel, there is good reason to suspect a lack of lime. 

 To determine more definitely, the following suggestions will 

 be of service : — 



Soils which contain any considerable amount of carbonate 

 of lime are either neutral in their action upon litmus paper, 

 or, as is usually the case, they are alkaline. A neutral soil 

 does not change the color of either a blue or red litmus 

 paper. An acid soil will turn a blue paper red and an alka- 

 line soil will turn a red litmus paper blue. To learn if a 

 soil is acid (sour), take a tablespoonful or more of soil and 

 place it in a glass or cup, moisten with sufiicient water to 

 make it about like a very thick paste. If possible, allow it 

 to stand fifteen minutes to an hour, though in very acid soils 

 the test will readily show at once. With a knife blade part 

 the soil and introduce one end of a piece of blue litmus 

 paper, one-fourth to one-half an inch wide and two inches 

 long, taking care not to touch the fingers to the end intro- 

 duced. Press the soil against the paper. After from five to 

 fifteen minutes, remove the paper, rinse the soil from it as 

 hastily as possible, taking care not to wash the blue color 

 from above into the portion of the paper that was in the 

 soil, and if it has turned distinctly red, there is evidence that 

 lime is needed. If the soil has a strong reddish tint, as is 

 sometimes the case, and tends to cling to the paper, bring 



