Every spring-sowing season, many farmers ask our agronomy team: “We already applied autumn fertilizer. Now that we’re sowing in spring, should the first irrigation also include fertilizer?” Once you clearly understand the timing and purpose of base fertilizer, seed fertilizer, seedling fertilizer, and topdressing , the answer becomes obvious. I. Base Fertilizer: The “Nutrient Foundation” for the Entire Growth Cycle 1. Definition Base fertilizer — also called pre-plant fertili