340 STATE BOARD OF AGRICULTURE. 



til the plants had made a good start. Sui-facc watering was then discon- 

 tinued, in the tanlc two feet in lieighl the plants grew to maturity and 

 appeared normal. In the tanlc four feet in lieiglit a few weak plants 

 grew to be six to eight inches higli and tlieu died, the majority of the 

 plants, however, died slH)rlly alter surface watering was discontinued. 



In the six and eight feet tanks the i»lants died as soon as surface water- 

 ing was discontinued. From these results it appears that the water table 

 in sands of this character must be very near the surface in order to grow 

 normal crops. This conclusion is boi-ne out by Held observations. In 

 the nortliern part of the state a large area of sand was drained by the 

 construction of a large dredge ditch. The ditch was dug extremely deep 

 thus lowering the water table to suoh an' extent that crops could not be 

 grown successfully on the area when the rainfall Avas low. It was found 

 necessary to dam the ditch in order to raise the water table before satis- 

 factory crops could be grown. 



A preliminary report of results obtained from studjdng the composi- 

 tion and concentration of the soil solution as measured by the freezing 

 [)(>int lowering of the root and leaves of plants, appear in Soil Science 

 Vol. Ill, pages 113-138, 191G. This project is being continued and promises 

 to be a fertile research field. 



The movement of soluble salts through soils of different texture and 

 water content, together with tlie changes induced in the composition of 

 the soil solution in various layers are being studied. The results ob- 

 tained show that salts move from regions of high to those of lower con- 

 centration even in closed containers, such movement being accompanied 

 by changes in the composition of the soil solution. Field studies are 

 underAvay to determine to what extent, if any, soluble salts rise from the 

 subsoils. 



The lime and green manure studies mentioned in last year's report 

 are being continued. In the latter, comparisons of the lasting effect of 

 limestone of different fineness of division, marl and hydrated lime are 

 being made. It is proposed to make an exhaustive study of this problem. 



During the year, R. S. Bogan made comparisons of the lime require- 

 ment of soils as determined by the Jones, Veitch, and Freezing Point 

 methods respectfully. A large number of widely different samples of 

 soil taken from several counties were employed. In all cases virgin 

 soils were compared with those that had been cropped many years — -in 

 most cases until ''catches" of clover were impossible without the use of 

 lime or stable nmnure. The result jjresented reveals that the virgin 

 soils often show a higher lime requirement than those cropped many 

 years, upon which clover fails. Moreover, the methods give different re- 

 sults for the same soil samples. It thus seems that laboratory' methods 

 for determining the lime requirement of soils for maximum returns may 

 be misleading. We are forced to so conclude when we recall that the 

 virgin soils as a rule Avould doubtless produce nmny excellent crops of 

 clover without the use of either lime or manure. It seems that the field 

 trial method is the only reliable one to use to determine the optimum 

 amount of lime to apply. 



