Effects of combined application of slow-release nitrogen fertilizer and urea on nitrogen uptake, utilization and yield of maize under two tillage methods

Objective The objective of this study is to investigate the effects of the combined application of slow-release nitrogen fertilizer and urea on soil water use efficiency, dry matter accumulation, nitrogen uptake and utilization, operation and yield under two tillage methods. Method Qiangsheng 388 was selected as the test material, and under rotary tillage (R) and rotary tillage + subsoiling (R + S), the fertilization methods of CK (no fertilization), U (100% urea), S (100% slow-release nitrogen fertilizer) and different UNS ratios (urea and slow-release nitrogen fertilizer) were set up for two years in field experiments. Result The results showed that compared with CK, U and S, UNS significantly improved water use efficiency, dry matter accumulation, nitrogen uptake, operation and yield. Among them, UNS2 (the ratio of S and U was 7:3) was the best. In 2022, R UNS2 had the best water use efficiency, dry matter accumulation, nitrogen uptake, operation and yield, which were 5.05%, 2.0%, 3.88%, 6.18% and 4.06% higher than those of R + S UNS2, respectively. In 2023, R + S UNS2 had the best treatment, which was 1.98%, 2.52%, 1.85%, 2.60% and 2.20% higher than that of R UNS2, respectively. Conclusion R + S tillage can effectively improve maize yield, nitrogen uptake and utilization, water use and dry matter accumulation; Nitrogen application treatment UNS2 treatment was the best. In summary, R + S UNS2 is the best coordination strategy.