The Huttig news., 1911-11-25
Improvement of Soils.

study have demonstrated that plants take up from the soil at least ten elements which are re- quirsd for their growth and devel- opment under normal conditions. These elements are phosrhorous, potassium, nitrogen, colcium, mag nesium, sulphur. chlorine, silicon, iron and sodium. though the pro- portion of some of these clements needed in plant nutrition is very small. Most of these elements Tn fact. are contained in most soils in sufficient quantities to meet the requirements of plants for an in- definite period, and the number of elements liable to rapid exhaustion are limited in most cases to the three first named, viz: Phesphor- us, nitrogen and potassium, while in exceptional cases it becomes necessary to take account of and replace the lime (calcium) re- moved from the soil by continuous cropping. It has also been shown that the crop producing capacity of soil is, as a rule, measured by  that essential fertilizing constitu- e. t, which exists in the soil in the smallest quantity, and 1t becomes necessary to increase the supply of the different element or ele- ments in the soil m order to secure a satisfactory return from the cul- tivation of the soil in question. Whether the farmer applies to his land the crude domestic manures or the commercial fertilizers pre- pared by the manufacturer, the ob- ject in view in each case is the same and the end he desires to att tain is to prevent exhaustion of his soil by supplying in another form the essential fertilizing element : removed thereflom by a giyen. crop.
 Where the land is utilized Tn the growing of forage crops, the pro- dLcts are frequently fed to stock upon the farm, sni the farm yard manure, if properly collected and preserved, will restore to the soil a large proportion of the fertilizing material removed from the land by the crop itself. Where the crop is cotton, proportion of the loss of valuable soil constituents, is com pensated for by the application of the seed obtained as a secondary product or else the cottonseed mealitself is employed with a view to furnishing the constituents in a more concentrated from. Even where the greatest economy and care is practiced, the farmer can make good only a portion of the losses of soil constituents. by the application of domestic manures and by products from the crop it. self. and 1t b 3comes necessary to supplement these crude fertllizing materials with commercial ma nures, carefully selected with re- ference to the needs of given soil or crop. It is an established fact that certain crops have well defined preferences for given fertilizing constituent, while crops of different character may re- auire relatively only small amount of that particular sub stance to meet their needs. For instance, the tobacco plant upon given soil will require large suc- cessive applications of potash to produce satisfactory crop, while cotton may be grown for a number of years on the same soil without the addition of potash from extern. al sources. or else with the appli- cation of much smaller amounts of this constituent than were. re- quired for the tobacco plant. The cereals require liberal supplies of nitrogen in the soil for their full growth and development, while on the other hand, the leguminous crops by reason of their capacity for assilimilated of nitrogen from the air. can be successfully grown
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