What should be the minimum level of nutrients in compound fertilizers?
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At my previous workplace, a total nutrient level of 48 was considered acceptable, with levels above 47.5 deemed qualified; for a total nutrient level of 40, 39.95 was considered acceptable； For the current standard, 48 requires a value of over 47.6, while 40 requires a value of over 40.01 to be considered qualified. Which one is more suitable? Is there any established standard regarding the lower limit for nutrients? Thank you!
Generally, operations are carried out in accordance with national standards, but different organizations may have their own requirements.
According to national standards, for values greater than 40, such as 48, the requirement is that they be no less than 48; for values equal to or less than 40, such as 40, the requirement is that they be no less than 40.0； As mentioned above, should 48 and 40.0 be considered as 47.5 and 39.95 based on the minimum rounded value?
I think this is determined based on customer requirements. For products like those from our company with specifications of 25, 35, and 40, negative deviations are not allowed; this rule comes from quality inspections and customer demands. For other nutrients, the lower limit is -0.3 and the upper limit is +0.8. As for the production formula, it is determined whether it meets the standards based on the results of inspections conducted by the quality control department.
According to GB 15063-2009, for products with contents of 40.0%, 25.0%, and 30.0%, the actual content must reach 39.95% and 24.95% respectively. A percentage of 29.95% or higher is considered qualified; for other products that do not have a decimal point in their percentage value (such as 48%), a level of 47.6% is sufficient to be considered qualified.
Thanks! Follow-up question: 1. According to the rounding standards, would 47.51% meet the requirements for 48%? 2. In the actual production process, requirements of 48.0% or 45.0% have not been encountered; the requirements are always 48% or 45%. But if such requirements of 48.0% or 45.0% do arise, does it mean that 47.95% or 44.95% is required in order to meet the standards? 3. The national standard specifies only ≥40.0%, without setting any requirements regarding the decimal place for values above 40. So, which requirement should be followed regarding whether the maximum allowable fertilizer content is 48% or 48.0%?
Follow-up question: 1. According to the rounding standards, would 47.51% meet the requirements for 48%? It meets the requirements. 2. In the actual production process, requirements of 48.0% or 45.0% have not been encountered; the requirements are always 48% or 45%. But if such requirements of 48.0% or 45.0% do arise, does it mean that 47.95% or 44.95% is required in order to meet the standards? If the customer has a special requirement for zeros after the decimal point, it will be as you said. 3. The national standard specifies only ≥40.0%, without setting any requirements regarding the decimal place for values above 40. So, which requirement should be followed regarding whether the maximum allowable fertilizer content is 48% or 48.0%? The national standard specifies only 25.0%, 30.0%, and 40.0% (not just 40.0%); all other values are treated as having no digits after the decimal point.