Effects of Topdressing Frequency on Growth and Yield of Maize in Aeolian Sandy Soil under Fertigation

【Objective】 Fertilizer topdressing is an agricultural practice to provide crops with additional nutrients, but how topdressing frequency affects crop growth and yield is inadequately understood. The objective of this paper is to determine the optimal nitrogen topdressing frequency for improving maize cultivation in aeolian sandy soil. 【Method】 The experiment was conducted in a maize field with nitrogen fertilizer applied in one (F1), two (F2), four (F3), seven (F4) and eleven (F5) topdressings. For each treatment, we measured the growth and grain yield of the maize. 【Result】 Topdressing once at the jointing stage or before the earing stage increased vegetative growth, stem length and diameter, leaf area index, and SPAD content. In contrast, multiple topdressing improved spike length and diameter, kernel numbers per spike, and 100-seed weights, ultimately leading to an elevated yield. The grain yield depended not only on topdressing frequency but also on when and how the fertilizer was applied in each topdressing. For example, in the multiple topdressing, applying fertilizer during earing and tasseling stage reduced the kernel numbers, 100-seed weights, yield, and fertilizer use efficiency. Aligning fertilizer application with plant requirements in the multiple topdressing was critical to improving plant growth. Among all treatments, topdressing 11 times was optimal, with the yield reaching 7.36 t/hm2, irrigation water use efficiency, water use efficiency, nitrogen use efficiency reaching 3.27 kg/m3, 1.25 kg/m3 and 24.52 kg/kg, respectively. 【Conclusion】 Increasing the frequency of fertilizer topdressing proves to be a highly effective strategy for improving maize growth and yield in aeolian sandy soil, presenting a promising approach for optimizing fertilization in this region.