The Bulletin. 35 



POTASH. 



The mountain types so far studied, without exception, contain 

 iin ahuiidance of potash in the surface soil for the production of 

 maximum crops for several hundred years. It is more a problem 

 of making this supply available than of increasing it. Not only do 

 the chemical analyses show that there is an abundance of potash in 

 these soils,* but in no case do we find any marked increase in yield 

 due to its use, and frequently the yield is actually reduced. It cer- 

 tainly would give better immediate returns and would be far more 

 beneficial to eliminate potash altogether for general farm crops, and 

 put the money into an additional supply of phosphoric acid. Potash, 

 however, can be applied with profit to tobacco and very probably to 

 Irish potatoes. 



LIME. 



The plat results already obtained on both upland and valley land 

 indicate that burned lime can be used at a profit for temporary gains. 

 These soils are not strongly acid, neither are they lacking in lime; 

 therefore, the beneficial results obtained from the use of lime must 

 be due, not to the correction of acidity, or to the effect of lime as 

 a plant food, but rather to the liberation by the burned lime of the 

 plant food already in the soil. This process of the liberating of plant 

 food by burned lime is destructive, as it reduces the amount of plant 

 food in the soil. This effect, though justifiable so far as potash is 

 concerned, on these soils so low in phosphoric acid and nitrogen, is 

 certainly not to be desired. Furthermore, in liberating nitrogen 

 organic matter is destroyed, and much of the nitrogen in it may be 

 lost. Unburned lime, calcium carbonate, does not have these de- 

 structive effects. Therefore it would seem that the unburned lime is 

 preferable in the case of the mountain soils, with the possible excep- 

 tion of the Porter's black loam or other soils containing high amounts 

 of organic matter and phosphoric acid. On these burned lime may 

 prove more profitable. 



CROP ROTATIONS AND PERMANENT AGRICULTURE. 



It is the duty of every owner of agricultural land in this or any 

 other section of the State to follow methods of crop rotation and 

 fertilization which shall maintain the producing power of the fertile 

 soils, and which shall build up that of the poorer ones. Our methods 

 of farming should be such that the soils would become more pro- 

 ductive year by year. The one great purpose in the present inves- 

 tigation of North Carolina soils as outlined in the begining of this 



• In some cases the composition is as high as 5% which is nearly half as much as is contained in 

 kalnit. It would require in this case something like 400 tons of kainit to supply aa much potash as 

 is contained in the top 6 2-3 inches of an acre. 



