User manual HANNA INSTRUMENTS HI 38050

[. . . ] 7 CONVERSION FACTORS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 WARNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 CHEMICAL REACTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Nitrate-nitrogen is not durable in soil. The large amount required for crop production, makes it necessary to administer this element in moderate quantities during the crop growth season. An excess of Nitrogen weakens plants' structure creating an unbalanced relationship between the green and wooden parts. In addition, the plant becomes less resistant to diseases. Furthermore excessive nitrogen fertilization can contaminate groundwater and cause environmental problems. The Hanna Nitrate Test Kit for Soil and Irrigation Water makes it possible to determine the need for nitrogen fertilization. It also obtains the best crop response and avoids over-fertilization. TEST PROCEDURE FOR DETERMINING NITRATE IN IRRIGATION WATER READ THE ENTIRE INSTRUCTIONS BEFORE USING THE KIT 1- Using the plastic pipette, fill each glass vial with 5 mL of water sample (up to the mark). 2- Insert one of them into the left hand opening of the 5 mL checker disc. This is the blank. THE NITROGEN CYCLE Nitrogen is the most abundant element present on our planet and can be found in many different forms. Only a very small part of the total nitrogen is available for plant growth. The exchanges between available and unavailable nitrogen combine to form a complex system which is called the nitrogen cycle. 3- Add to the other glass vial 1 packet of HI 38050-0 reagent. Replace the cap, shake vigorously for 1 minute and wait for 5 minutes. 4- Remove the cap and insert the reacted sample into the right hand opening of the checker disc. 5- Hold the checker disc so that a light source illuminates the samples from the back of the windows. 6- Keep the checker disc at a distance of 30-40 cm (12-16") from the eyes to match the color. Rotate the disc while looking at the color test windows and stop when you find the color match. Read the value in the result window directly in mg/L (ppm) of nitratenitrogen (N-NO3-). Multiply the reading by 4. 43 to obtain mg/L of nitrate (NO3-). Note: Perform the reading three times and take the average value (divide by 3 the sum of the three numbers). 4 9 CONVERSION FACTORS 1 kg 1 ha 1 kg/ha 1 ppm (soil) 1 ppm (irrigation water) 1 ppm N 2. 205 lb. 2. 471 acre 0. 891 lb. /acre 1 mg/kg 1 mg/L 4. 43 ppm NO3 Note: Legumes (soybean, pea, clover, alfalfa, etc. ) are able to take atmospheric nitrogen by a symbiotic association with Rhizobium bacteria. WARNING This test gives accurate results for most soil types, nevertheless, some local circumstances can cause erroneous readings. Therefore use this test always with caution. Whereas an insufficient dose of nutrients decreases the potential crop production, an excess can have a detrimental effect on the physiology of the plants and the crop quality. [. . . ] manure or anhydrous ammonium), then use the lower value of recommended fertilizer. Take more samples to assure your mixed sample is a representative one for your field. HOW TO PROGRAM NITROGEN FERTILIZATION When this test is used for the first time, it is better to perform it during a complete growth cycle without changing the normal fertilization program. This helps to familiarize oneself with this test and provides a good reference point in order to improve the fertilization program. In the subsequent growth cycle, preplant fertilization rate should be reduced by approximately 30%. [. . . ]