Nitrogen-rich fertile soil

What to do Do not overfeed with nitrogen-rich fertilizers. Use a potassium fertilizer if rust is a regular problem. Improve the drainage of soil if necessary. Use a crop rotation. Grow more resistant leek cultivars such as Poristo and Poribleu. Do not overcrowd seedlings. Clear away and compost any diseased plant debris. 

Agriculture demands vast quantities of fertilizers to supplement soil nutrients this is critical when the same land is used year after year for crop production. Essential nutrients are N, P, K (the three required in largest amounts), Ca, Mg and S plus trace elements. In 2002, in the US, direct use and its conversion into other nitrogenous fertilizers accounted for 88% of all NH3 produced. In addition to NH3 itself, the nitrogen-rich compound C0(NH2)2 (urea) is of prime importance, along with... 

The primary use of ammonium nitrate is the manufacture of fertilizers. In 2005, about 2 million metric tons (2.2 million short tons) of ammonium nitrate fertilizer was used in the United States. The compound is added to soil to provide the nitrogen that plants need to grow. It may he used by itself or in combination with another nitrogen-rich compound, urea, in a mixture known as UAN. 

Often, the rates of fertilization in intensively managed agriculture are intended to satiate the needs of crop plants for these chemicals, so their productivity will not be limited by nutrient availability. However, excessive rates of fertilization have important environmental costs. These include the contamination of ground water with nitrate eutrophication of surface waters caused by nutrient inputs (especially phosphate) acidification of soil because of the nitrification of ammonium to nitrate large emissions of nitrous oxide and other nitrogen gases to the atmosphere, with implications for acid rain and Earth s greenhouse effect and the need to use herbicides to control the weeds that flourish under artificially nutrient-rich conditions. 

Sow seeds indoors 10 weeks before last spring frost. Seeds need light to germinate, so don t cover them. After the last frost, transplant outdoors into rich, well-drained soil and moderate shade. Too much sun fades leaves and causes drooping. Feed with high-nitrogen fertilizer to encourage leaf development. 

Sewage sludge is rich in organic matter, nitrogen and phosphorus and may be used as fertilizer and soil-conditioner. It may be applied for the remediation of disturbed soil cover, for instance, in the areas of mining. The typical rates are of hundreds of tons per hectare. In these areas, artificial landscapes can be made up by planting trees and grasses. 

Ammonia is the primary basic gas in the atmosphere and, after N2 and N20, is the most abundant nitrogen-containing compound in the atmosphere. The significant sources of NH3 are animal waste, ammonification of humus followed by emission from soils, losses of NH3-based fertilizers from soils, and industrial emissions (Table 2.8). The ammonium (NH ) ion is an important component of the continental tropospheric aerosol. Because NH3 is readily absorbed by surfaces such as water and soil, its residence time in the lower atmosphere is estimated to be quite short, about 10 days. Wet and dry deposition of NH3 are the main atmospheric removal mechanisms for NH3. In fact, deposition of atmospheric NH3 and NH4" may represent an important nutrient to the biosphere in some areas. Atmospheric concentrations of NH3 are quite variable, depending on proximity to a source-rich region. NH3 mixing ratios over continents range typically between 0.1 and lOppb. 

To sum up vegetables are often surprisingly rich in nitrates. If surplus fertilizers are used to increase the amount of nitrogen in soils, this may further exaceibate the problem. The solution is controversial artificial fertilizers with reduced nitrogen content must be used, and natural fertilizers should also be apphed with extra care. Needless to say, these precautions will decrease the yield of the vegetables. 

Kohlrabi seeds may be planted as soon as the soil can be cultivated in the spring. The vegetable may also be planted in the summer for harvesting in the fall. A rich soil is needed for high-quality kohlrabi. Therefore, it is often desirable to fertilize with nitrogen, phosphorus, and potassium. 

In addition to seed meal, the husks of the fruit that bears castor seed is a significant coproduct of castor oil production. Castor meal is sold and used as fertilizer, as it is rich in nitrogen, 7.54% N, which is 10 times that of steer manure (Lima et al., 2011). The authors found that castor meal in excess of 4% prevented germination and caused plant growth inhibition or death, but a mixture of 4.5% meal and 5.5% husk promoted plant growth. While the meal is rich in N and P, the husk is rich in K, providing a balanced soil amendment that also adds organic material to the soil. 

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