冬种黑麦草对农田杂草及其种子库的影响

Effects of planting ryegrass on farmland weeds and seedbank in winter

农田杂草的萌发、生长,明显地依赖于土壤中活动的杂草种子库。2009-2010年冬季,在广州市农业科学研究所花都基地构建的"黑麦草(Lolium multiflorum)-蔬菜"轮作系统中,通过对大田杂草种类和数量的跟踪调查,以及用诱萌法对土壤中杂草种子库的研究,探讨我国南方农区冬种意大利黑麦草对农田杂草的影响。结果表明,在冬闲时种植黑麦草可以很好地抑制农田杂草的发生,还可以减少土壤中活动的杂草种子数量。在冬季种植黑麦草和菜心(Brassica parachinensis)后的试验田中,重新种上蔬菜后发现,黑麦草区内的平均杂草数目仅为菜心区的25.00%,冬闲区(对照区)的23.28%;而且,种植黑麦草后的土壤中,活动的杂草种子数量下降了67.85%;另外还发现,冬种黑麦草还可以影响农田中杂草种类,减少甚至避免农田中植株较大的杂草的生长。因此,冬种黑麦草不仅可以生产优质牧草,还可以降低杂草对农作物的危害。

The seed germination and growth of weed in farmland rely on the active seedbank obviously.To identify if planting ryegrass in fallow farmland in winter can reduce the active seedbank of the soil,present study investigated the number and species of weed and weed seedbank in the field of a rotation system with ryegrass and vegetables in Guangzhou City from 2009 to 2010.The results showed that planting ryegrass in the winter fallow land significantly reduced the weed seeds in the soil.The amount of weeds in the field originally planted with ryegrass was only 25.00% and 23.28% of that in the field originally planted with cabbage and the fallow land on average;and the active weed seedbank in the soil after planting ryegrass was only 67.85% of the original land.In addition,planting ryegrass in the winter fallow land could also affect the dominant species of weeds in the farmland;it could decline the larger weeds.Generally,planting ryegrass in the winter fallow land not only produced good quality forages,but also reduced the harm to crops by the weeds.