摘要
以马铃薯克新13号脱毒种薯为材料,在相同氮肥用量下,设置不同生育时期施氮的田间小区试验,通过测定主要生育期植株各器官干物重和含氮量,研究施氮时期对马铃薯不同器官氮素积累、分配及块茎产量和质量的影响。结果表明,马铃薯在营养生长期的吸氮素量仅为全生育期的1/3,块茎形成中期达到马铃薯的吸氮高峰期,块茎增长后期至成熟期块茎中的氮素主要来自营养器官的二次分配。与N 150 kg/hm2全部做基肥相比,将1/3的氮在块茎增长初期追施可使商品薯产量提高25%(P<0.05),达到30.01 t/hm2。氮肥利用率达到44%(P<0.05)。适宜氮肥用量下,基肥和追肥的合理分配是获得马铃薯高产优质的重要条件,基肥氮不足,氮肥集中在苗后施用,则易导致植株贪青。试验在肥力中等的土壤种植马铃薯,150 kg/hm2氮素用量条件下,将2/3的氮作基肥施用,1/3的氮在块茎增长初期追施,较有利于养分在块茎中的分配,同时也能获得最高的块茎产量。
The study was carried out to analyze the characteristic of N accumulation and distribution in potato plants with the same N application rate but different application time, with cv. Kexin 13 used in the field experiments. Four treatments were conducted with the same N application rate but different application patterns. The N needed by potato plants in vegetative growth stage was only 1/3 of the total N needed over the whole growth period. The potato plants needed much more N from the tuber initiation stage and reached the peak value at the middle tuber bulking stage. After that the differences of the N accumulation among different organs came from the second allocation of N stored in plants. Combination of pre-plant and in-season N application was necessary to increase N uptake efficiency and produce higher yield and higher quality potato tubers. Compared to all 150 kg N / ha applied at planting, the 100 N kg/ha applied at planting plus 50 kg N/ha applied at early tuber bulking stage increased the marketable tuber yield by 25% （P〈0.05）and increased the N use efficiency （NUE） by 19 percentage points. Optimal N application should meet the plants need in different growth stage and keep the balance between vegetation growth and reproduction growth. Insufficient basal N application combined with dressing large amount of N at emergence and early tuber bulking stage would cause the plants remaining green when harvested. So, on loamy soil with medium level of fertility, 2 / 3 of the total N 150 kg / ha should be applied as basal fertilizer and the rest 1 / 3 dressed at early tuber bulking stage.
出处
《中国马铃薯》
2011年第6期350-355,共6页
Chinese Potato Journal
基金
公益性行业科研专项(201103003)
