Effects of sowing pattern and one-time application of controlled-release fertilizer on dry matter accumulation, remobilization, and yield of winter wheat

Objectives We investigated the effect of one-time basal application of controlled-release fertilizers on the photosynthetic characteristics and dry matter accumulation and remobilization of winter wheat, under wide-belt sowing and conventional drilling sowing condition, to provide technical support for the labor-cost effective fertilization in winter wheat.

Methods In the 2020–2021 growing season, field experiments with split design were carried out in Tai’an and Weifang cities, Shandong Province. Two widely planted cultivars, Tainong 18 and Taimai 198, were selected as the experimental materials. The main plots were conventional drilling sowing and wide-belt sowing; and the subplot was four nitrogen fertilizer treatments: conventional urea with multiple application (F1), and stable urea, humic acid blended controlled release nitrogen fertilizer, and resin coated nitrogen fertilizer, denoted as F2, F3, and F4, respectively, with one-time application as basal fertilizer. The net canopy photosynthesis rate, duration of net high photosynthesis rate of wheat canopy (DNHP), dry matter accumulation before and after anthesis (DMAB, DMAA), and remobilization before anthesis (DMRB), grain yield and yield components were investigated.

Results Compared with conventional drilling sowing, wide belt sowing increased the spikes per unit area, N uptake post anthesis, net canopy photosynthetic rate post anthesis, DNHP post anthesis and DMAA by 48.0×10⁴/hm², 12.4 kg/hm², 7.9 μmol CO₂/(m²·s), 5.6 days and 920.7 kg/hm², respectively, and increased the yield by 902.6 kg/hm². Under both sowing patterns, the DMAA was positively and linearly correlated with the DNHP post anthesis, and the latter positively and linearly correlated to the N uptake post anthesis. Compared with F1, the N uptake post anthesis and DNHP post anthesis were significantly decreased under F2, F3, and F4, with the decrement ranging from 21.8 kg/hm² and 2.6 days under wide belt sowing, and 27.2 kg/hm², and 4.5 days under conventional drilling sowing, respectively. Under wide belt sowing, the relatively lower decrement of DMAA (631.4 kg/hm²) could be compensated by the increment of DMRB (551.7 kg/hm²), while under conventional drilling sowing, a relatively higher reduction of DMAA (1054.8 kg/hm²) could not be remedied by the increase of DMRB (540.6 kg/hm²).

Conclusions Regardless of fertilization method, wide belt sowing elicited higher winter wheat yield than drilling sowing. The one-time application of three controlled release fertilizers did not decrease winter wheat yield as the compensation for high dry matter accumulation before anthesis under wide belt sowing, not under conventional drilling sowing. Thus, one-time application of controlled-release fertilizers should not be chosen under conventional drilling sowing method.