No. 4.] MANUKIAL PROBLEMS. IS? 



dilute aminoiiia water, — and 3011 will sec after letting it 

 stand a few hours whether you have a blacli. extract. If you 

 get a l)lack extract, you may be sure the soil is in need of 

 lime. The tests are described in Bulletin No. 4G, which I 

 can send to any one who will make a])})lication for it. 



Mr. Ware. In mentioning amounts of lime did you 

 mean air-slacked lime? 



Dr. Wheeler. No, calcium oxide. 



Mr. Ware. It amounts to how nmch air-slacked lime? 



Dr. Wheeler. I think the ap})lication of I ton to | 

 ton once in five or six years is necessary to maintain the 

 conditions we want. Sometimes, at the outset, if the soil is 

 acid, it may be necessary to put on 1 or 11 tons of air-slacked 

 lime. If I had a soil that was very hea^ y clay, or contained 

 a large amount of humus, — black, sour humus, — I might 

 use two tons of lime to an acre, dependent on the crop to 

 be grown. On light, sandy soil I should want to use only 

 1 or I ton. 



Mr. Ware. Do plants assimilate lime? 



Dr. Wheeler. All higher plants do. 



Mr. Ware. Why don't we have it given in analyses? 



Dr. Wheeler. It is an essential plant food, and some- 

 times has not been reported in the analyses, because we have 

 heard so much of the three essential elements that we have 

 forgotten sometimes that lime may be as essential as those 

 three. 



Mr. Ware. You spoke in regard to the grass crop, that 

 w^here you employed nitrate of soda you had plenty of herd's 

 grass, and wdtli nitrogen it increased ; where you used no 

 nitrogen all the herd's grass disappeared. Did the roots of 

 the herd's grass die ? Weren't they all there ? 



Dr. Wheeler, xipparently at the end of five years most 

 of them were dead. 



Mr. Ware. This change seemed to be in one year? 



Dr. Wheeler. What I was talking about w^as producing 

 grass of a high grade. In that case plenty of manures and 

 lime will insure maintenance of timothy. 



Mr. Moore (of Orange). Is it possible to compost our 

 green manure with materials other than lime, for instance, 



