350 MISCELLANEOUS FARM SUBJECTS 



lence of certain trees or weeds frequently offers safe indications of 

 soil conditions and of crop adaptations. 



The character of the native vegetation frequently affords a 

 very safe guide to the prevalence and amount of alkali salts con- 

 tained in the soils of any particular locality. Some native plants 

 are not found where the salt content exceeds 0.20 per cent. Other 

 plants are characteristically found where the salt content is very 

 much higher. These indications, however, differ in different places, 

 and for different types of alkali. 



It is a well-known fact that cultivated crops differ as regards 

 the amount of alkali and this varies with the character of alkali 

 which they can withstand. Alfalfa is exceedingly sensitive. Sor- 

 ghum and sugar beets, on the other hand, are very resistant. In 

 the development of the tobacco interests in the Miami Valley, Ohio, 

 the sugar maple was taken as a safe indication of the soils on which 

 the best grades of tobacco could be produced. 



Perhaps nowhere is the use of character of the native vegetation 

 as a guide to the utilization of soils more marked than in certain 

 areas in Florida. With little or no Observable difference in the 

 character of the soils, the hammock land, with its luxuriant growth 

 of hardwood trees, is considered the strongest and most reliable land 

 for the general crops of the locality. The high pine land, with its 

 sparse growth of 'well-developed pine, is second in importance, be- 

 ing adapted, under intensive methods of cultivations, to the pro- 

 duction of early truck and vegetables, though rather less valuable 

 for citrus fruits than the hammock land. The lighter members 

 of the sandy types, if not too coarse, are adapted to the early spring 

 vegetables, the intermediate loam types are adapted better to wheat, 

 corn, cotton, and general farm crops, under suitable climatic con- 

 ditions, and the heavy clay types are better for grass and soiling 

 crops for dairying and stock raising. This is general over the east- 

 ern half of the United States, but not specific, as there are many 

 modifying influences. For instance, a rather fine sand in a low 

 situation where a more moist condition than usual is maintained 

 produces good yields of wheat. Also, after the intensive fertiliza- 

 tion given truck or tobacco a good crop of wheat may be produced 

 on land too light for profitable culture in this crop under general 

 farm methods. It may therefore be given a place in rotation with 

 special crops when it would not be advisable to grow it under less 

 intensive culture given other crops. Also when clover runs out 

 and has to be omitted from the rotation it is often inadvisable to grow 

 wheat on a soil which would otherwise be considered suitable, be- 

 cause the yields can not be maintained without the intervening 

 clover crop. 



Corn may often be recommended for a soil not particularly 

 adapted for this crop, because of its value in the rotation and as a 

 necessary feed for farm stock. Such utilization of soils is only 

 justified when other crops equally valuable for forage and grain 

 and better adapted to the soil can not be found. 



