منابع مشابه
Nitrogen and Soil Fertility
amounts involved are much smaller. The amount of boron in the 7-ton potato crop (if determined) would have been about 0.2 pound. In the case of boron (and to a lesser degree the other micronutrients) if the soil contains excessive amounts, toxic quantities are absorbed by plants and growth is restricted. The need for a reasonable balance in amounts of available nutrients in the soil has been po...
متن کاملSoil Fertility - Chap 01
If all resources are harnessed, and adequate measures taken to minimize soil degradation, sufficient food to feed the population in 2020 can be produced, and probably sufficient for a few billion more. These were the key conclusions from a Discussion Meeting held at the Royal Society in London in December 1996. The meeting entitled ‘Land resources: on the edge of the Malthusian precipice?’ atte...
متن کاملIron and Soil Fertility
Fertilizers that are essentially sulfurfree have been used increasingly. Ammonium nitrate, anhydrous ammonia, urea, and ammonia solutions are examples among the nitrogen carriers. The use of concentrated superphosphate and other phosphorus carriers with little sulfur has been expanding. We recommend that farmers in areas of potential deficiency should have a planned program of adding sulfur ins...
متن کاملManganese and Soil Fertility
variety of crops. Pot tests indicated that addition of about 200 p.p.m. of copper from copper sulfate produced a toxic reaction in soils low in copper, but otherwise comparable to Alsatian vineyard soils, which were found to contain as much as 400 p.p.m. of copper. Among the crops tested, vines were most resistant to copper toxicity; clover and alfalfa were most sensitive. Symptoms of copper po...
متن کاملSoil Fertility and Bean Production
Beans require adequate amounts of all essential plant nutrients for optimum growth but only a few nutrients are documented to be needed for southern Idaho soils. These nutrients include phosphorus (P), nitrogen (N), zinc (Zn), potassium (K), sulfur (S), and to a much less extent B, Cu, Mn and Fe. University of Idaho Agricultural Experiment Station research as well as research from throughout th...
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ژورنال
عنوان ژورنال: Science
سال: 1915
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.42.1088.632