Screening Methods of Soil Nutrients

Balanced and matched fertilization is based on the application of farmyard manure and straw to fertilize fertility. Based on the target crop yield, soil fertility, and fertilizer effects, it is scientifically matched with N, P, K and trace fertilizers to provide reasonable The time and method of application to achieve high yields and improve soil fertility are one of the important contents of the "fertile soil project" at the end of the "Ninth Five-Year Plan" period of the Ministry of Agriculture. The key to popularizing balanced fertilization technology is to solve the rapid determination of nutrient data such as organic matter, available phosphorus, and available potassium in different soils, and to grasp the soil fertility, as an important basis for determining the type, quantity, and fertilization methods for applying fertilizers. Soil nutrients are determined using conventional domestic soil analysis methods. Although the reliability, accuracy, reproducibility, and precision of the analysis results are all good, the first is the need for sophisticated equipment and a large number of chemical reagents; the investment is large; The process analysis is technically strong, and requires a certain level of professional education to be mastered after special training. Third, the analysis procedure is cumbersome and time consuming, and it cannot solve the problem of rapid determination of a large number of soil samples. In this regard, we conducted a screening and application study of the soil speed measurement method.
1 There are two or more rapid test methods for organic matter, available potassium, and pH for the screening of soil organic matter, available potassium, and rapid acidity and alkalinity. Which method is suitable?
Organic matter has potassium dichromate oxidation colorimetric method and complex alkali solution colorimetry. Soil nutrient determination method we use potassium dichromate oxidation colorimetric method, because it is easy to operate, color tone changes significantly, easy to distinguish, make the standard color scale suitable for all kinds of soil types of advantages, and complex alkali solution ratio When the color method is used to extract different soil types with the EDTA extractant, the leaching amount of the humus is inconsistent, and the color tone of the leachate is also different. Therefore, the uniform standard color scale cannot be used to quickly measure the organic matter content of different soils. There are five soil types in Zunyi City, and eight soil types in Guizhou Province. It is very troublesome to create a standard color scale for each soil type. In addition, Guizhou is a mountainous region. The arable soil is scattered and fragmented, and the types are staggered. Before the rapid measurement of soil organic matter, it needs to be divided. And to distinguish the soil type, labor and time-consuming.
Available potassium is tetraphenylboron sodium turbidimetric method and sodium nitrite turbidimetric method. We choose the former. Because, first, sodium tetraphenylborate and potassium ions in the test solution are in the alkaline medium at pH 8, forming fine white particles of tetraphenylborate with extremely low solubility (1.8×10-5 mol/L). It is stable in the liquid, that is, the turbidity is stable, and the turbidity determination result is stabilized. Second, the potassium tetraphenylborate is generally not affected by changes in room temperature, and can be measured at room temperature in different seasons. The sodium nitrite sodium cobalt nitrite method has a high solubility (2×10-3 mol/L), which is more than 100 times the solubility of potassium tetraphenylborate, and its measurement is also affected by the change of room temperature.
There are 4-8, 7-9, 4-11, etc. indicators in the colorimetric method of pH indicators. According to the standard of soil acidity and alkalinity, pH<4.5 is strongly acidic soil; pH>8.5 is strongly alkaline. Soil, therefore, a mixed indicator with a pH of 4.5 to 8.5 was used, and the color gradation and color tone changed significantly.
2 Quick colorimetric soil color card production using soil colorimetric colorimetric method, made into a soil colorimetric color card, colorimetric card booklet determination items have water content, pH, organic matter, ammonium nitrogen, nitrate nitrogen, quick effect Phosphorus and quick-acting potassium were used. Seven items such as measuring methods, operating procedures, calculation of results, colorimetric color scales and nutrient grading standards for colorimetric determination items were included in the colorimetric booklet, which was convenient to use and carry.
The soil moisture content was determined using the alcohol combustion method.
The soil acidity and alkalinity were determined by mixed indicator colorimetry. The colorimetric card was used to determine the pH value of 4.5 to 8.5, which was divided into 9 different color gradations. The pH difference between adjacent gradations was 0.5 and the hue difference was obvious. Compared with the conventional analysis acidometer method, it can save 9/10 time.
Determination of soil organic matter, using potassium dichromate sulfuric acid oxidation colorimetric method, the use of concentrated sulfuric acid to dilute the heat, without heating equipment, without calibration and titration, simple operation, color gradation, color change significantly, easy to distinguish.
Organic matter measurement range 0.5 ~ 5.0g/kg, divided into 9 color levels, the difference between adjacent color levels 0.5g/kg. The standard color scale is made with glucose. It can save 4/5 of the time than conventional analysis and reduce the use of ovens and analytical instruments.
Soil nitrate-nitrogen determination was performed using a nitric acid powder colorimetric method with a range of 2.5-80 mg/kg, divided into 6 color grades for use in dryland soil determination.
Determination of ammonium in soil, using Na’s reagent colorimetric method, determination range of 2.5 ~ 80mg/kg, divided into six levels, used for rice soil determination.
Determination of soil available phosphorus, the use of molybdenum blue colorimetric method, the measurement range of 3 ~ 50mg/kg, divided into seven color levels, compared to conventional analysis to save about 7/8 of the time, and reduce the use of analytical balance and spectrophotometer.
Determination of available potassium in soil, using sodium tetraphenylborate turbidimetry, the determination range of 25 ~ 200mg/kg, divided into 6 turbidimetric reading grade. The colorimetric analysis saves about 4/5 of the time compared to conventional analysis and does not require expensive instruments such as flame photometers.
The use of color cards to solve the problem of non-standard color scale in organic texts in professional textbooks and soil pH, available phosphorus, ammonium nitrogen, and nitrate nitrogen in textbooks. Despite the standard color gradation, it is still due to printing and other reasons. The color difference of the color scale is very large and cannot be practically used.

Electric Airless Sprayer with piston pump is specifically designed for the professional painter, equipped with EzControl system and TEFC Brushless DC motor. 
It's the ideal choice for contractors who need a higher output Airless Paint Sprayer for daily use on residential jobs. It is the portable sprayer with maximum flow.
Electric Airless Paint Spray Machine Advantage
1)  Proven Pump can ensure exceptional life
The imported leather V-packing also provide the machine longer lifetime.

2)  Exclusive Brushless DC Motor
Brushless DC Motor-Never change brushes with this maintenance-free, which makes the machine work efficiently no matter low or high speed.

3)  Easy out Manifold Filter
Easy out manifold filter will reduce the tip clogs. The pump filter could be disassembled by hand easily.

4) Smart Pressure Control system
Latest pressure control system delivers a consistent spray fan at all spraying pressure. And with digital display, you can read and regulate the pressure easily. The microprocessor will generate the fast response when spraying.

5) Stainless Steel Rack.
Stainless steel Rack makes the machine firm stand


Electric Airless Paint Sprayer

Electric Airless Paint Sprayer,Electric Airless Sprayer,Wall Spray Paint Machine,House Painting Machine

Fuzhou HVBAN Mechanical Equipment Co., Ltd. , http://www.hi-sprayer.com