施氮水平与种植密度互作对鲁东小麦病虫害发生、产量与氮素利用率的影响

Effects of Interaction between Nitrogen Rate and Planting Density on Pest and Disease Occurrence,Yield,and Nitrogen Use Efficiency of Wheat in East Shandong

为了探明施氮水平与种植密度互作对鲁东麦区病虫害发生、产量及氮素利用率的影响,于2018—2019、2019—2020年小麦生育季,选择太麦198、山农30、济麦23等3个小麦品种为试验材料,在大田条件下设置4个施氮水平(120、180、240、300 kg/hm^(2))和4个种植密度(太麦198设置90万、180万、270万、360万株/hm^(2),山农30和济麦23均设置135万、270万、405万、540万株/hm^(2)),探究施氮水平与种植密度互作对鲁东小麦茎基腐病、纹枯病和蚜虫发生、产量与氮素利用率的影响。结果表明,小麦纹枯病、茎基腐病的发病率和病情指数随着施氮水平及种植密度的增加而升高,并且该试验条件下增加施氮量对病害发生的提升效应高于提高种植密度,说明虽然增加施氮量或种植密度均会造成病虫害发生的加重,但适度密植配合适量减氮的氮密组合在控制病害发生方面优于高施氮与低密度组合,有利于降低病害防控压力,表现出较高的减药潜力。施氮180 kg/hm^(2)与太麦198的270万株/hm^(2)或360万株/hm^(2)、山农30和济麦23的405万株/hm^(2)种植密度组合,能在获得相对较高氮素利用率的同时实现高产,有利于鲁东小麦的减肥增效。综上,在鲁东麦区可以通过合理密植配合适量减氮,在控制病虫害发生的同时,以密补氮确保植株养分吸收积累和干物质生产,从而实现高产高效稳产。

IIn order to investigate the effect of the interaction between nitrogen rate and planting density on the occurrence of diseases and pests,yield,and nitrogen use efficiency in the wheat region in east Shandong,in this study,three wheat cultivars(Taimai 198,Shannong 30,and Jimai 23)were used as the test materials during the 2018-2019 and 2019-2020 wheat growing seasons,four nitrogen rates(120,180,240,300 kg/ha)and four planting densities(0.9,1.8,2.7,3.6 million/ha for Taimai 198;1.35,2.7,4.05,5.4 million/ha for Shannong 30 and Jimai 23)were set under field conditions to explore the effects of nitrogen rate and planting density on the occurrence of wheat stem rot,sheath blight and aphids,yield,and nitrogen use efficiency.The results showed that the incidence and disease index of wheat sheath blight and stem rot were aggravated with the increase of nitrogen rate and planting density.Compared with planting density,the increase in nitrogen rate had a stronger effect on the occurrence of wheat disease,indicating that although increasing the nitrogen application rate or planting density would worsen the occurrence of diseases and pests,the combination of moderate dense planting with appropriate nitrogen reduction was more effective than the combination of high nitrogen application rate and low density.This approach helped to reduce the pressure of disease prevention and control and showed high potential for reducing the need for chemical treatments.The combination of 180 kg/ha nitrogen application with 2.7 million/ha or 3.6 million/ha of Taimai 198,and 4.05 million/ha of Shannong 30 and Jimai 23,could simultaneously achieve high yield while achieving relatively high nitrogen use efficiency.This was beneficial for reducing fertilizer use and improving the efficiency of wheat in east Shandong.In conclusion,reasonable dense planting combined with appropriate nitrogen reduction could be used to control the occurrence of diseases and pests,at the same time,reasonable dense planting ensured the absorption and accumulation of nutrients for plants,and dry matter production,accomplishing high yield,high efficiency,and stable yield in the wheat region in east Shandong.