Effects of different moisture and different temperatures on soil nitrification
Nitrogen is one of the main factors limiting the productivity of various ecosystems. Soil organic nitrogen must be transformed into inorganic nitrogen that can be absorbed and utilized by plants through the action of soil microorganisms. This process is called nitrogen mineralization. Studies have shown that temperature, moisture and other factors affect the process of soil nitrogen mineralization.
From the perspective of the composition of mineralized nitrogen, the nitrate nitrogen content increased significantly, while the ammonium nitrogen content decreased, which may be in the process of nitrification, that is, NH4-N is rapidly oxidized to NO2--N, and further oxidized to NO3-- The continuous increase of N and NO3--N concentrations inhibits the growth of denitrifying bacteria, further inhibits the conversion of NO2--N to NO3--N, and may result in the loss of some N2O during the nitrification process. In forest soils, the release of ammonia was also observed. Studies have shown that the maximum net mineralization rate usually occurs at 25~35°C, and the optimum soil mineralization rate of typical grassland is 15~35°C, and it increases with the increase of temperature. Zhang Shulan et al.'s study believes that 20 °C can delay nitrification, but the rate is reduced. 30 °C is the most suitable soil nitrification temperature in Shaanxi, and the critical point of microbial activity in temperate forest soil is around 20 °C. It shows that nitrification is dominated by the mineralization process, and the optimum mineralization temperature range varies with the soil type, which is the evolutionary adaptation of nitrifying microorganisms. The temperature can be measured with the temperature and humidity autograph.
The study found that under the same water conditions, the maximum net mineralization rate appeared at 25°C. The net mineralization rates at 5 and 15°C were significantly lower than 25°C, indicating that the net mineralization rate had a turning point at 15°C, indicating that 25°C is beneficial to The nitrification of black soil, the critical temperature of nitrification in the soil of alfalfa grassland in autumn is about 15°C. Self-reporting thermo-hygrometers are used to determine the temperature at which the maximum net mineralization rate occurs, and can keep track of changes in temperature and record. At low temperature, both ages show net nitrogen retention. Under low temperature conditions, nitrogen mineralization mainly accumulates NH4+-N, which is expressed as nitrogen retention. This is because the process of nitrification is slowed down at low temperature, and nitrifying bacteria are more than ammoniated microorganisms. It takes longer to adapt to the cold environment. As the culture temperature is gradually reduced, the microbiological nitrogen and total nitrogen retention rate will also increase due to the growth of suitable microbial populations. The nitrifying bacteria are aerobic microorganisms whose activity is strongly affected by the partial pressure of nitrogen in the soil, which in turn is affected by the soil moisture content. In general, as soil moisture content increases, the soil nitrogen mineralization rate increases, nitrification. The optimum moisture content range is from 50% to 70% of the maximum water holding capacity in the field. It is also reported that under the condition of 15-30°C, the nitrification rate of sandy loam relative to the soil moisture content of 30% to 60% is close to that of Nitrification is insensitive to soil moisture.
High speed door
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Material Selection:
1. Frame: 2MM thicknesses cold-roll Stainless steel.
2. Motor: Germany SEW brake motor (outer), power 0.75KW, power supply 220V.
3. Control system: Imported Japan Mitsubishi converter and PLC to control of electric box (150%1HZ)
4. Opening & closing speed: 0.6-1.5m/s (adjustable).
5. Safety Device: Korea Photocell Sensor, emergency stopping reaction when sensing obstacles.
6. Curtain: France high-density polyester fiber and the surface coating processing, thickness 0.8MM, variety colors can be chose: Red, yellow, blue, green, orange, gray, white, transparent, etc. Tensile strength: 4000/3500N/5cm, tear strength 600/600N. Fire-proofing level: German standard DIN75200 Usage temperature: -30 ° C +70 ° C.
7. Wind resistant: The Aluminium alloy Reinforce Girder to increase wind resistant effect.
8. Curtain replacement function: Aluminium alloy Reinforce Girder is loaded between 2 pieces Curtain, can be replaced easily if any curtain broken, save your cost.
9. Transparent window: 1.2MM thickness transparent PVC window, size and location is up to your request, more safer.
10. Seal: Seal brush are Installed inside the guides, and the special bottom design, to fit any uneven ground.
11. Cotrolling way: Push button + radar sensor, very convenient.
12. Limiting Switch: Mechanical limiting switch, easily and exactly.
13. Emergency STOP: With emergency stop button on control panel, can stop easily by
Hand once disconnect or accident
14 Fault recovery function: All Hongfa's production is with fault recovery function, system will self-recovery after power cut off.
15. Delivery time: About 7 business days with contract and deposit confirmed.
16. Pyament item: 50% before production, and the other 50% before shipment.
17. Warranty Details: We provide 12 months warranty for all doors and accessories (except man-made disasters, Irresistible natural disasters, ect^).
We have many professional engineers with rich experience, qualified products, perfect service system, and good cooperation relationship with many famous companies.
We have the best solution for you, and we provide all the support you need to achieve optimum results, or value, or both, from whatever products you buy.
We provide 12 month warranty for all product and accessories. And custom made door size/color/material.
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