Effects of15Nitrogen-Labeled Gel-Based Controlled-Release Fertilizer on Dry-Matter Accumulation and the Nutrient-Uptake Efficiency of Corn

Effects of a new gel-based controlled-release fertilizer (G-CRF) on the growth and nutrient uptake efficiency of corn were investigated based on a pot experiment. The fate of fertilizer nitrogen (N) was also studied by 15N tracer method. The results showed that, compared with conventional fertilizer, the G-CRF had significant effects on increasing dry matter, N, phosphorus (P), and potassium (K) accumulations, which increased by 6.4% (P < 0.05), 14.2% (P < 0.01), 8.0% (P < 0.01), and 6.0% (P < 0.05), respectively, in the mature stage. The 15N tracer experiment showed N-uptake efficiency in G-CRF treatment increased by 8.0% and loss rate decreased by 8.9% compared with conventional fertilizer treatment. Application of G-CRF improved P and K uptake efficiency by 5.8 and 11.6 percentage points in the mature stage. Thus, the results implied the G-CRF tested could provide essential plant nutrients including N, P, and K and delay the release of them efficiently. Moreover, G-CRF had significant effects on improving nutrient-uptake efficiencies and plant yield.