98 BOARD OF AGRICULTURE. [Jan., 



to the black matter mentioned by Grandean, or to the total 

 organic matter. 



It 's a fact that some of the most fertile soils in the United 

 States have neither a large amount of " black matter " nor of 

 total organic matter. The soil of the Experiment Station 

 farm in Rhode Island was found to contain from 3V2 to 3^ 

 per cent, of " black matter " or far more than many of the fer- 

 tile soils referred to above. In addition a considerable amount 

 of less fully decomposed organic matter was also present. 

 Here one would suppose there must surely be an abundant 

 supply of " humus," but yet as a matter of fact so large an 

 amount of the very fine " black matter " is present that it 

 seems to injure rather than benefit the physical character of the 

 soil. Notwithstanding the large amount of " humus," as the 

 term is ordinarily used, the further introduction of vegetable 

 matter, either undecomposed or in the first stages of decom- 

 position, seems to improve the condition of the soil greatly for 

 certain varieties of plants. Such matter is in condition to 

 lighten the soil and improve its tilth, but if already in the stage 

 of the " black matter " as described by Grandeau, the same re- 

 sult could not be expected. 



WHY WAS LIME BENEFICIAL TO THE RHODE ISLAND SOILS? 



The question which arose early in the history of the lime 

 investigations in Rhode Island was : How is lime beneficial ? 

 If it was helpful solely as plant food then this deficiency could 

 only be revealed by field tests with plants or by complicated 

 laboratory methods. If lime was needed because the soils of 

 Rhode Island were acid, then the simple test with blue litmus 

 paper was likely to reveal the need. This is a test which it 

 is possible for every farmer to make. It is also one by which 

 hundreds of soils can be tested in Station laboratories in a short 

 time at small expense. If lime were needed solely for physical 

 reasons it seemed possible tliat land plaster or other lime com- 

 pounds might prove equally or more efficient. At all events 

 the importance of answering why lime was needed must be ob- 

 vious to all. 



If lime helped by virtue of correcting an acid condition of 

 the soil it was to be expected that similar benefit would result 

 from the use of still other substances that could neutralize 



