Show IN FORMATION OF ALKALI SPOTS sal ne incrustation upon surface of soli SON hinders vegetation and annoys the farmer it appears that within the past nun num oer of beals more than ever before a phenomenon resulting un question ably from the dry summers and rath er moist springs and falls in differ fint sections of the middle northwest has come under the observation of the farmers it is a saline incrustation apon the surface of the soil it hinders vegetable growth and causes annoyance to the farmer wherever such s spots pots are found the alkali spots some times appear of light whitish gray olor and form a narrow ring on the outer edge where the water and land seem to touch or meet in a pond or mud puddle this happens where the land Is low the soil rich in plant food and the soil in need of drainage alkali spots are prevalent in our western states particularly in the arid regions they are caused prin cipully by the capillary movement of soil water which comes from lower zones of soil and contains in solution saline and soluble matters feces sary to the ithe growth of the plant the alkali spots are more in evidence in the late summer in times of drought and when the evaporation of moist ure from the surface of the soil ex ceede the amount of rainfall and the percolation of water in the soli soil the upward capillary movement of moisture Is very slow it Is incessant so long as there Is any tiny out outgo go of water mater from the upper layers of the soil either through mere evaporation or by force of exhalation of water by the growing plants capillary movement acts with equal density by day and by night the e evaporation v ap oration of water from the surface of the land will usually be largest during the day when the sun Is shining on the soil and on the plants that are growing on it during the night when the evaporation is checked the capillary movement with in the soil still goes on and has in III so tar far better opportunity to supply moisture from below to make good what has been post from the surface during the preceding day when a sheet of water stands over a field and there Is no capillary movement there the physical forces in the soil under such condition are practically at a standstill but when water Is removed and the pore space in the soil becomes open and to a de gree tree free from water evaporation from surface of soil takes place and capillary begins to act the salts at the surface are brought up but not evaporated like moisture would be it Is this action that gives rise to the accumulation of salts near sur face of soil in wet fields |