Detailed Explanation of Nutrient Uptake Patterns of Rice at Different Growth Stages

The nutrient uptake of rice at various growth stages differs considerably depending on the type. Double-season rice has a short growth period, especially the shortened vegetative growth period in the field, so vegetative growth and reproductive growth overlap shortly after transplanting. That is, tillering in the field begins at the same time as panicle differentiation, and the peak tillering stage occurs during panicle differentiation, thus forming a prominent nutrient uptake peak 2 to 3 weeks after transplanting; single-season rice forms two nutrient uptake peaks 2 to 3 weeks and 7 to 9 weeks after transplanting.

The uptake rates of various nutrients by rice all reach their maximum before heading, after which the rates tend to decrease. Among the various nutrients, nitrogen, phosphorus and potassium are absorbed the fastest, reaching their maximum values about 20 d before heading; silicon reaches its maximum absorption later.