Annual report ..[bulletins and circulars] . ^ for use in the soil. There is aplant-food which the roots seek and find,so that everj^ plant whichsends roots into the soil takes something from it to build in theplant tissue. The sharp edges of some sedges, which will cutthe hand like a dull knife, and the wood ashes left when a wood. 14.—A boulder-strewn soil of glacial origin with one of the large erraticson the left similar to those which early attracted attention to the page 42. fire is burned, represent in part this plant-food obtained fromthe .soil. Let us take a handful of soil f
Annual report ..[bulletins and circulars] . ^ for use in the soil. There is aplant-food which the roots seek and find,so that everj^ plant whichsends roots into the soil takes something from it to build in theplant tissue. The sharp edges of some sedges, which will cutthe hand like a dull knife, and the wood ashes left when a wood. 14.—A boulder-strewn soil of glacial origin with one of the large erraticson the left similar to those which early attracted attention to the page 42. fire is burned, represent in part this plant-food obtained fromthe .soil. Let us take a handful of soil from the field, the school yard,or the street and examine it. We find it to be dirt that soilsthe hands ; and when we try to brush off the dirt we notice agritty feeling that is quite disagreeable. This is due to the bitsof mineral in the .soil ; and that these are hard, even harder thana pin, may often be proved by rubbing soil against a piece ofglass, which the hard bits will scratch, while a pin will not. 37 Study this soil with the eye and you may not see the tiny bits,though in sandy soils one may easily notice that they are bits ofmineral. Even fine, loamy and clay soils when examined witha pocket lens or a microscope will be found to be composed oftiny fragments of mineral. It is evident that in some waymineral has
Size: 2268px × 1102px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherithac, bookyear1899
