SWEET CLOVER 199 



in Montana Neill (23) reports a diminished yield where the 

 alkali content was about 4000 parts per million, mostly 

 of sodium sulphate, while Kearney (17) places the highest 

 quantity under which alfalfa will succeed at 6000 of this 

 salt. Very few important crops will grow with larger 

 quantities of these alkalies in the soil. In most soils, 

 there is a mixture of the salts in various proportions so 

 the limits of the separate salts serve only for general 

 purposes. The high resistance of alfalfa may be assigned 

 to its deep feeding habits in many cases, the feeding roots 

 not being in the alkali zone but being in the purer solu- 

 tions below. 



Sweet clover (Melilotus alba and M. officinalis) is widely 

 recommended for alkali lands. It is as resistant as alfalfa 

 and is often preferred to alfalfa for alkali land. Coe (1) 

 states that it will withstand so much black alkali that 

 salt grass is the only other crop that can compete with it 

 on this kind of land. It gives more satisfaction than 

 alfalfa on alkali lands which are water-logged or have a 

 shallow water-table. Sweet clover is not ordinarily so 

 satisfactory a forage crop as alfalfa because it is necessary 

 to reseed it every alternate year, whereas alfalfa yields 

 well for years. It is so difficult to secure a good stand 

 of these crops under alkali conditions that it is very de- 

 sirable to have a continuous or perennial crop. Sweet 

 clover is easier to get started on alkali land than alfalfa. 

 It requires more care in harvesting because if it is allowed 

 to grow too long it acquires a disagreeable flavor and it is 

 not so readily eaten as alfalfa. The few observations on 

 the resistance of sweet clover to alkali show it to rank 

 about with alfalfa, so that other conditions being equal 

 alfalfa is the preferable crop. However, on water-logged 

 land or where alfalfa does not thrive for other reasons, 



