Does zakat become obligatory on an agricultural yield of five qintars, and if it does, how is it calculated, keeping in mind that we do not pay zakat unless it reaches ten qintars?

If the crop reaches the zakat (definition) threshold, which is 2.5 quintals or 653 kilograms, zakat becomes obligatory on it. One-tenth is to be given if it was irrigated by rain or springs, and half of one-tenth if it was irrigated by machinery. Zakat must be paid for previous periods in which it was not rendered, despite the threshold being reached, because it is a debt upon one's conscience that does not lapse with the passage of time.