绿肥全部还田条件下烤烟化肥氮用量调整研究

Adjustment of N fertilization rate in flue-cured tobacco production when applying green manure

采用田间小区试验研究了绿肥全部还田条件下不同施氮水平对烤烟生长发育以及烟叶产量、产值和品质的影响。结果表明:在绿肥全部还田条件下,不同氮肥用量对烤烟株高、烟叶SPAD值、烟株干物质累积以及烤后烟叶产量、产值和化学成分均有一定的影响。与对照(即绿肥地上部不还田,按当地传统习惯施肥)相比,施氮量为60%的烟株农艺性状表现较好,产量、产值和上等烟比例分别增加5.68%、23.57%和34.33%,同时烟叶内在化学成分更为协调;而施氮量为80%和100%两处理的烟株田间有贪青晚熟现象,产量最高,但产值小于施氮量为60%的处理,而高于对照;施氮量为40%以及不施氮肥处理的烟株成熟较早,产量和产值相对较低。综合而言,在绿肥全部还田条件下,烤烟化肥氮施用量以当地习惯推荐量的60%为宜。

Field experiment was carried out to study effect of different nitrogen rate on growth,yield and quality of flue-cured tobacco when applying green manure to soil. Results showed that nitrogen fertilization rate significantly affected tobacco plant growth,leaf SPAD value,dry matter accumulation,leaf yield,economic value as well as chemical components. Compared with control which was supplied with nitrogen at traditional recommended rate even in the condition that roots of green manure were remained in soil,treatment with nitrogen supplied at 60% of the recommended rate and with all green manure applied to soil,resulted in better growth,higher leaf yield and better quality. Leaf yield,economic value,and superior leave percentage were increased by 5.68%,23.57%,and 34.33%,respectively. While for treatments with nitrogen supplied at 80% or 100% of the recommended rate and with all green manure applied to soil,field growth were delayed and the highest leaf yield were obtained,but economic value was lower than the one with 60% nitrogen rate although it were still higher than control. Tobacco plant fertilized with 40% nitrogen rate or without applying any chemical nitrogen yielded less than other treatments due to earlier maturity. It suggested that nitrogen rate applied to tobacco plant be reduced at least 40% when applying green manure to soil,in order to obtain desirable leaf quality and higher economic value.