Bulletin, Volúmenes48-60U.S. Government Printing Office, 1908 |
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Términos y frases comunes
absorbed absorption alkali ammonia ammonium aqueous solutions Average for area Average for type Bureau of Soils CaCO3 Caddo Parish calcium carbonate carbon dioxide carboxylic acid Cecil cent Chem Chim compounds concentration condition curves decrease dihydroxystearic acid dioxide in aqueous effect Escambia County Grams growth attributable humic acid humus hydroxide increase in growth ingredients Jour Leonardtown Leonardtown loam liquid liter magnesium carbonate manure method moisture content nitrate of soda nitrogen Norfolk fine sandy Norfolk sand obtained optimum water content Orangeburg organic matter P.ct particles penetration percolation phosphate Phys Podunk fine sandy potash potassium chloride pots Prairie County precipitate pressure quantity quartz quartz flour rate of evaporation Rusk County salts sample sandy loam saturated sodium chloride soil grains solu solubility substances sugar surface temperature tion U. S. Dept volume changes water vapor Waycross Waycross area weight of plants wetting Zeit
Pasajes populares
Página 115 - With potash the form does not exert so great an influence upon availability as is the case with nitrogen and phosphoric acid. All forms are freely soluble, in water, and are believed to be nearly if not quite equally available as food. The form of the potash has an important influence upon the quality of certain crops. For example, the results of experiments seem to indicate that the quality of tobacco, potatoes, and certain other crops is unfavorably influenced by the use of muriate of potash, while...
Página 126 - form" as applied to a fertilizing constituent has reference to its combination or association with other constituents which may be useful, though not necessarily so. The form of the constituent, too, has an important bearing upon its availability, and hence upon its usefulness as plant food. Many materials containing the essential elements are practically worthless as sources of plant flood because the form is not right ; the plants are unable to extract them from their combinations ; they are "unavailable.
Página 125 - Soils vary greatly in their capabilities of supplying food to crops. Different ingredients are deficient in different soils. The .way to learn what materials are proper in a given case is by observation and experiment. The rational method for determining what ingredients of plant-food a soil fails...
Página 126 - It is not good economy to pay' high prices for materials which the soil may itself yield, but it is good economy to supply the lacking ones in the cheapest way. The rule in the purchase of costly commercial fertilizers should be to select those that supply, in the best forms and at the lowest cost, the plant-food which the crop needs and the soil fails to furnish.
Página 126 - ... returns when used for crops of relatively low value. The agricultural value is distinct from what is termed "commercial value," or cost in market. This value is determined by market and trade conditions, as cost of production of the crude material, methods of manipulation required, etc. Since there is no strict relation between agricultural and commercial or market value, it may happen that an element in its most available form, and under ordinary conditions of high agricultural value, costs...
Página 239 - The root cap is slightly, if at all, colored ; the zone of primary meristematic cells immediately back of the root cap is marked by a distinct narrow band of color; the zone of actively growing cells in the region of greatest elongation is not intensely colored; the more slowly growing portions of the root possess the purplish color, but it becomes less intense as one passes to the upper parts of the root. The superior Oxidizing power of the meristematic tissues of the plant is not only shown by...
Página 9 - shall not appear upon any bag or other package of any acid phosphate with potash which shall contain by its guaranteed analysis less than 11 percent available phosphoric acid and 1 per cent potash, or a grade or analysis of equal total commercial value; that the words "High grade...
Página 126 - ... plant-food which the crop needs and the soil fails to furnish. Plants differ widely with respect to their capacities for gathering their food from soil and air; hence the proper fertilizer in a given case depends upon the crop as well as upon the soil. The fertility of the soil would remain practically unchanged if all the ingredients removed in the various farm products were restored to the land. This may be accomplished by feeding the crops grown on the farm to animals, carefully saving the...
Página 9 - High grade" shall not appear upon any bag or other package of any plain acid phosphate...
Página 56 - ... presentation by Forester Gifford Pinchot and of the further conviction of the then head of the Bureau of Soils of the Department of Agriculture, as follows: The soil is the one indestructible, immutable asset that the nation possesses. It is the one resource that can not be exhausted; that can not be used up. As a national asset the soil is safe as a means of feeding mankind for untold ages to come. But, by the time Franklin D. Roosevelt came to the presidency, the evidence that all was not well...