so-called sour grasses are not acid. They may be just the opposite 

 especially when they are surrounded by limestone hills whence lime 

 is carried in the natural waters into the marsh. 



Is Your Soil Sour? 



Soils are sour when they lack sufficient limestone carbonates to 

 counteract or neutralize acids that may occur in both the poorest 

 and the richest of soils. Many of our farms which grow big crops 

 of corn and potatoes need lime to grow alfalfa. 



I do not wish to say all soils need lime. That is not true. Very 

 rich soils will sometimes grow alfalfa even though they are quite acid. 

 But_so many soils need lime that all should be tested for sourness 



Fig. 20. It Tells How Much Lime the Soil Needs. 



Truog's test not only determines the acidity of the soil but gives 

 the amount of lime required to grow alfalfa successfully. 



or acidity before attempts at alfalfa growing are made. These tests 

 are simple. They will save thousands of dollars that are annually 

 wasted in trying to grow alfalfa on soils too sour for a healthy growth 

 of this crop. 



The Litmus Test 



Not long ago a grower "of alfalfa told me: "The first time I tried 

 testing my soils with blue litmus paper I did it on the sly. I didn't 

 want anyone to know about it, because I really didn't think there 

 was much to it. I bought a dime's worth. Just for my own satis- 

 faction I tried it out with some vinegar and it did turn right red. 



"Then I went up into one field where I never could get alfalfa 

 started. It had rained the day before, so the soil was moist. I 

 made a slit in the ground with my knife, put a strip of the litmus in, 

 and closed the dirt about it. I left it there for five minutes and then 

 removed the dirt. Well, sir, that paper had turned to a sort of mot- 

 tled pink. That meant the soil was sour. I tried it in three or four 

 places by taking handfuls of dirt and making them into balls with 

 the litmus in the center, and they all did the same thing. 



"I WES just curious enough to haul out three loads of waste air- 

 slaked lime that I got from our dealer and put it on one acre. The 

 next year I inoculated and seeded down to alfalfa and got an excel- 

 lent stand The litmus test may not be absolutely reliable for all 

 soils, but it's a mighty close indicator of soil acids. 



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