SOILS AND FERTILIZERS 373 



eolution (1 to 1,000) or formalin be omitted, or serious injury from 

 potato scab will be likely to result- 

 Fifth. In liming in the course of a rotation, applications at 

 intervals of from five to six years are usually sufficient. The lime 

 should, if possible, be applied just before a crop which is especially 

 likely to be helped by it, and the more indifferent crops may be in- 

 troduced later. 



Sixth. The lime may be slaked in small piles in the field or in 

 larger piles at one side, or it may be air-slaked in a water-tight build- 

 ing, so that there may be no danger of fire. In the case of small 

 piles, some moist soil thrown over the lime facilitates slaking. Sprin- 

 kling the burned lime with the proper amount of water will make 

 it slake quickly to a powder. 



Seventh. Magnesian lime may sometimes be used to advan- 

 tage in place of pure lime, but it should not be used repeatedly on 

 the same land. (Bu. of Chem. B. 30; Fla. E. S. B. 83; An. Rpt. 

 Del. E. S. 1899; Ore. E. S. B. 90; Univ. 111. B. 110; Fla. E. S. B. 

 93; Of. Ex. Sta. F. I. Lecture 3; F. B. 77.) 



TREATMENT OF ALKALI SOILS. 



Many ways of handling alkali soils have been tried in the past 

 with varying results. Remedies quite successful in one locality have 

 proven utter failures when tried in other districts. It is well to state 

 at first that no chemical means of treating white alkali has proved 

 economical or practical. 



Drainage. As poor drainage is usually one of the direct causes 

 of alkali, the first step in treatment is to supply the best possible 

 drainage. The high cost of tile drainage eliminates this method at 

 present, but a few open ditches will often remove the surface water 

 in the spring and prevent it from collecting in these low places. 



Cultivation. After the best possible drainage has been secured, 

 heavy application of strawy horse manure should be made at the rate 

 of from fifteen to twenty tons per acre during the summer or early 

 fall. The manure has three beneficial effects, first, it makes the soil 

 more open and porous, allowing better drainage, preventing both 

 puddling and baking; second, it will act somewhat like a mulch, 

 preventing surface evaporation and gathering of the salts at the 

 surface; third, it will supply the young plant with available plant 

 food in the spring, when the alkali soil, which is inclined to be cold 

 and dead, will not. Plow the land in the summer as deep as the 

 subsoil will permit. This will leave the soil open and exposed to 

 the snow and frost during the winter, which will tend to sweeten it 

 for the following year, as fall plowing always tends to do. In the 

 spring, as soon as the land is dry enough to permit, surface cultiva- 

 tion either with the cultivator, disc or spike tooth harrow should be 

 followed. This will prevent surface evaporation and form the best 

 possible seed bed for the crop. Thorough cultivation must always 

 be maintained upon alkali soil in the spring before the crop is 

 seeded. 



Crops. Next comes the question, what crop is to be tried upon 

 such soil? Experiments have proved conclusively that plants differ 



