关键词: 春小麦, 水氮减量, 宽幅匀播, 地上干物质, 产量构成

Abstract:

【Objective】Water shortage and high fertilizer input have become the dominant factors restraining spring wheat production in arid oasis irrigated areas. It is urgent to study the technology of the effects of water and nitrogen reduction in different planting modes on dry matter accumulation and yield formation of spring wheat, so as to provide a theoretical and practical basis for efficient production of spring wheat with water and fertilizer saving. 【Method】A field experiment with split-split plot was conducted at arid oasis irrigated areas from 2020 to 2021. Two planting modes, including wide-width uniform sowing (W) and conventional strip sowing (C), were designed, with two irrigation levels on local conventional irrigation (I2, 2 400 m³·hm^-2) and local conventional irrigation reduced by 20% (I1, 1 920 m³·hm^-2), and three levels of nitrogen fertilizer at a local conventional nitrogen (N3, 225 kg·hm^-2), local conventional nitrogen reduced by 20% (N2, 180 kg·hm^-2), and local conventional nitrogen reduced by 40% (N1, 135 kg·hm^-2). The adaptability of spring wheat yield to water and nitrogen reduction under wide-width uniform sowing and conventional strip sowing was studied. 【Result】Compared wtih conventional strip sowing, the wide-width uniform sowing increased the maximum dry matter growth rate (V_max), average dry matter growth rate (V_mean), and dry matter accumulation rate after booting stage of spring wheat, and delayed the time of emergence of the highest dry matter growth rate (T_m). Compared with conventional strip sowing with conventional irrigation and nitrogen levels, the V_max and V_mean values of spring wheat under the wide-width uniform sowing were increased by 13.0%-23.4% and 11.0%-16.9%, respectively, and T_m was delayed by 3.3-3.7 days with the treatment on the reduction of 20% for water and nitrogen, so the growth and development dynamics of spring wheat could be effectively regulated by wide-width uniform sowing. The wide-width uniform sowing had greater grain and biomass yields by 11.0%-17.3% and 4.3%-9.6%, respectively, and the greater harvest index by 6.3%-6.9%, than conventional strip sowing. Furthermore, the grain and biomass yields were 16.0%-22.5% and 5.6%-13.2%, and harvest index was 8.2%-10.9% greater under wide-width uniform sowing with the reduction of 20% in water and nitrogen than those under the conventional strip sowing with conventional irrigation and nitrogen levels. There was no significant difference in grain and biomass yields, and harvest index of spring wheat was found between the reduction 20% of water and nitrogen, and the reduction of 20% irrigation and conventional nitrogen application under wide-width uniform sowing. The increase of spring wheat yield was mainly attributed to the synergistic of grains per ear and 1000-grain weight, which were increased by 3.9%-7.1% and 18.4%-22.7%, respectively, compared with conventional strip sowing with conventional irrigation and nitrogen application, and the 1000-grain weight increased by a greater extent. Path analysis showed that the reduction 20% of water and nitrogen in wide-width uniform sowing enhanced grain yield mainly through increasing harvest index and 1000-grain weight. 【Conclusion】 The wide-width uniform sowing could realize the simultaneous reduction 20% of water and nitrogen in spring wheat production, which was a feasible measure to save water and nitrogen for stable and high yield of spring wheat in oasis irrigation areas.

Key words: spring wheat, water and nitrogen reduction, wide-width uniform sowing, aboveground dry matter, yield components