Navel orange peel residue selenium-rich fertilizer for cultivating high-quality selenium-rich navel oranges and preparation method of navel orange peel residue selenium-rich fertilizer

The invention discloses an application method of a navel orange peel residue selenium-rich fertilizer for cultivating high-quality selenium-rich navel oranges, which comprises the following steps: respectively spraying a selenium fertilizer on leaf surfaces of plants in any two periods of a flowering period, a young fruit period and a fruit swelling period of the plants, adding an activating agent, a microbial agent and a trace element supplement, and simultaneously reducing the proportion of inorganic selenium in the selenium fertilizer; the absorption and accumulation of selenium by plants are greatly improved, the tree body is protected from being damaged by inorganic selenium, and the problem of environmental pollution caused by the fact that the plants cannot completely absorb the selenium element of the existing selenium fertilizer is solved; the selenium fertilizer provided by the invention has a slow-release effect, solves the technical problems that the existing selenium fertilizer does not have a sl