华北旱地覆膜对春甘薯干物质和氮素生产特征的影响

Effects of Plastic Film Mulching on Dry Land on Dry Matter and Nitrogen Production of Spring Sweet Potato in North China

为了探求覆膜栽培对春甘薯产量、干物质和氮素生产特征的影响,以春甘薯品种冀薯99为试材进行大田试验,研究了地膜覆盖对甘薯产量,以及干物质和氮素积累与运转的影响。结果表明:雨养春甘薯的干物质生产表现为前期和后期积累快、中间慢的台阶式变化,氮素积累表现为前期快速积累、后期出现流失的特征。与裸地种植相比,地膜覆盖甘薯的氮素积累量增加20.56%,但氮素薯块转运率降低9.33个百分点。覆膜处理促进了甘薯的干物质积累,但降低干物质向薯块转运量达28.27%,最终,覆膜甘薯较裸地减产1.86%。而汛期揭膜处理的产量效果明显优于全程覆膜。甘薯覆膜栽培时,雨季揭膜是明显提高甘薯产量的关键。

The spring sweet potato variety Jishu 99 was used in this experiment,and the effects of plastic film mulching on the dry land on the yield,dry matter production and nitrogen accumulation and transloca-tion of spring sweet potato were studied. The results showed that the dry matter production character was fast accumulation in prophase and anaphase,and slow accumulation in middle stage. The nitrogen accumulation character was rapid in earlier stage and loss in later stage. Compared with the bare land planting,the nitro-gen accumulation with plastic film mulching increased by 20.56%,and the transport rate of tuber decreased by 9.33 percentage point. Plastic film mulching promoted the dry accumulation,while the transfer amount of dry matter to tuber decreased by 28.27%. So,the yield decreased by 1.86%. The yield effect of removing plastic film mulching in rainy season was better than that of film mulching in whole growth period,which was the key for increasing the yield of spring sweet potato.