A common question require to agriculturalist when troubleshooting a crop problem is , " What are you fertilizing with ? " and " At what concentration is that being applied ? " nursery growers often know what ppm ( constituent per million ) N ( nitrogen ) they are inseminate at because they mix their plant food according to the chart on the plant food bag . Human error and problems with plant food injectors can affect concentration and a grower might not be fertigating to the storey that they await . But how can growers be sure the fertilizer engrossment apply to the harvest is the same as the intended concentration ? Michigan State University Extension recommends tally the irrigation solution ’s EC ( electric conductivity ) to help oneself determine the actual ppm N in the crop ’s irrigation water .
Table 1 . A commercial-grade water - soluble fertilizer label put up the amount of juiceless fertilizer ( oz . ) to bestow to each gallon of pee to make a concentrated solution and the EC time value for a given ppm N. Note : The EC listed is of the diluted solution after fertilizer is injected into well-defined water
How to check fertilizer concentrationA high - timbre water - soluble fertiliser will put up a chart indicating the EC value to the corresponding ppm N ( tabular array 1 ) . For good example , in Table 1 , when blend at 100 ppm N , this fertiliser will have an EC time value of 0.64 mmhos . It is significant to observe this is not the EC of the concentrated stock solution , but the EC of the dilute solution after fertiliser is injected into clear H2O . These values list on the base are the EC values when fertilizer is tot up to double-dyed water system . Since most growers are irrigating with metropolis or well body of water ( not water treat with reverse osmosis or distilled water ) , they need to answer for for the EC economic value of the irrigation water before fertilizer is added .
To quiz the EC of unimpregnated irrigation piss , make full a 5 - gallon bucketful with the same water used to dilute the fertiliser and measure its EC value . Take this figure and subtract it from the EC economic value come out of the “ hose death ” ( irrigation water with fertilizer ) and liken it to the chart on the fertiliser bag .
For good example , suppose a agriculturalist ’s irrigation water with fertilizer had an EC of 0.78 mmhos , and their irrigation water without fertilizer had an EC value of 0.3 mmhos . In that slip , they are actually fertilizing at just about 75 ppm ( 0.78 EC of irrigation with fertilizer – 0.3 EC of irrigation with no fertiliser = 0.48 EC of fertilizer in irrigation water ) .
Although the chart in Table 1 does not specifically lean 0.48 mmhos , growers can square off that it corresponds to a N concentration of 75 ppm because 0.48 is halfway between 0.32 and 0.64 . When calibrating injectors , guarantee that the EC at the hosiery end ( water plus plant food ) is equal to the EC of the unclouded water plus the EC for your target N charge per unit from the bag .
Troubleshooting an incorrect concentrationIn summation to checking the injector for mechanical issues , some other tips to ensure the correct concentration of plant food are to :
Source : canr.msu.edu
