控制氮肥施用并增加作物产量已成为我国农业生产中急需解决的问题。本试验以不施氮肥（N0）为对照，设置常规施肥（N100）、2个减氮施肥处理（减氮20%、减氮40%）以及减氮+2个丛枝菌根（arbuscular mycorrhizal, AM）真菌处理的田间试验，探究减氮+AM真菌处理对AM真菌侵染发育情况、玉米产量性状、氮代谢相关酶活性以及氮肥吸收利用效率的影响。结果表明，减氮20%+AM真菌能够促进AM真菌侵染发育，提高菌根侵染率、丛枝着生率、孢子密度以及泡囊数。与N0处理相比，减氮20%以及减氮20%+AM真菌处理下玉米产量、穗长、穗粗、穗行数以及行粒数均有所增加，玉米氮肥农学效率（NAE）、氮肥吸收利用率（NRE）在减氮20%+AM真菌处理下表现最高，减氮20%+AM处理的玉米根系硝酸还原酶（NR）、亚硝酸还原酶（NiR）、谷氨酰胺合成酶（GS）以及谷氨酸合成酶（GOGAT）活性比N0处理分别增加140.4%~147.4%、96.1%~117.9%、131.5%~183.1%和122.8%~128.9%。同时，减氮20%处理以及减氮20%+AM真菌处理显著增加了玉米各生育期的地上部和地下部氮吸收量，土壤铵态氮和硝态氮含量也表现为不同程度的增加趋势，以玉米成熟期看，减氮20%+AM真菌处理下地上部和地下部氮吸收量最高，分别为109.33和39.94 kg/hm2，显著高于其他处理。减氮20%+AM真菌处理下的易提取球囊霉素相关土壤蛋白（EE-GRSP）、总球囊霉素相关土壤蛋白（T-GRSP）含量分别是N0处理的1.6-3.3倍以及2.7-3.6倍。结论认为:减氮20%并接种AM真菌能够提高玉米对氮的吸收量并增加氮肥利用率，促进氮代谢相关酶活性的提高，是增加玉米产量、减少氮肥施用的有效举措。

Controlling the application of nitrogen fertilizer and increasing crop yield has become an urgent problem in agricultural production in China. This experiment used no nitrogen fertilizer (N0) as a control, and set up field experiments with conventional fertilization (N100), two nitrogen reduction fertilization treatments (20% and 40% nitrogen reduction), and two arbuscular mycorrhizal (AM) fungal treatments to explore the effects of nitrogen reduction+AM fungal treatment on AM fungal infection and development, maize yield traits, nitrogen metabolism related enzyme activity, and nitrogen fertilizer absorption and utilization efficiency. The results showed that reducing nitrogen by 20%+AM fungi can promote the infection and development of AM fungi, increase the mycorrhizal infection rate, arbuscular growth rate, spore density, and vesicle number. Compared with the N0 treatment, the maize yield, ear length, ear diameter, ear rows, and grain number all increased under 20% nitrogen reduction and 20% nitrogen reduction+AM fungal treatment. The agronomic efficiency (NAE) and nitrogen uptake and utilization efficiency (NRE) of maize nitrogen fertilizer were highest under 20% nitrogen reduction+AM fungal treatment. The maize root nitrate reductase (NR) and nitrite reductase (NiR) were highest under 20% nitrogen reduction+AM fungal treatment The activities of glutamine synthase (GS) and glutamate synthase (GOGAT) increased by 140.4% to 147.4%, 96.1% to 117.9%, 131.5% to 183.1%, and 122.8% to 128.9%, respectively, compared to the N0 treatment. At the same time, the 20% nitrogen reduction treatment and the 20% nitrogen reduction+AM fungal treatment significantly increased the nitrogen absorption in the aboveground and underground parts of maize at various growth stages. The soil ammonium nitrogen and nitrate nitrogen content also showed varying degrees of increasing trends. In the mature stage of maize, the nitrogen absorption in the aboveground and underground parts was the highest under the 20% nitrogen reduction+AM fungal treatment, at 109.33 and 39.94 kg/hm2, respectively, which was significantly higher than other treatments. The content of easily extractable soil protein (EE-GRSP) and total soil protein (T-GRSP) associated with sacomycin under 20% nitrogen reduction and AM fungal treatment was 1.6-3.3 times and 2.7-3.6 times higher than that of N0 treatment, respectively. The conclusion is that reducing nitrogen by 20% and inoculating AM fungi can increase maize"s nitrogen absorption and nitrogen fertilizer utilization efficiency, promote the activity of nitrogen metabolism related enzymes, and is an effective measure to increase maize yield and reduce nitrogen fertilizer application.

山东省农业科技(2019LY003),国家自然科学基金(32071959)资助。