Effects of direct seeding methods on weed community composition and ecological niche in paddy fields in Chongqing,China
In order to efficiently and greenly prevent weeds in direct seeding paddy fields in Chongqing,China,the community composition and ecological niche of weeds in paddy fields under flooded direct seeding and wet direct see-ding were studied.The results showed that the weed communities in paddy fields under flooded direct seedig and wet direct seeding were composed of 16 species(belonging to 15 genera of 9 families)and 18 species(belonging to 17 genera of 10 families),respectively.Polygonum hydropiper and Bidens pilosa were endemic in the paddy field under wet direct seeding.The community structure of important weeds in paddy fields undre flooded direct seeding and wet direct seeding were composed of Ludwigia prostrata + Monochoria vaginalis + Echinochloa crus-galli and Lindernia procumbens + E.crus-galli + Alopecurus aequalis + Cyperus difformis,respectively.There were significant(P<0.05)difference in important values of important weeds(except E.crus-galli)between flooded direct seeding and wet direct seeding.Among the 14 important or major weeds both appreared under flooded direct seeding and wet di-rect seeding,the niche width of Echinochloa colonum,E.crus-galli,C.difformis,L.procumbens,A.aequalis,Juncus prismatocarpus,Paspalum distichum under flooded direct seeding were significantly reduced compared with that under wet direct seeding,and the niche oeverlap value of inter-species(except the inter-species of J.prismato-carpus and P.distichum)under flooded direct seeding were either significantly reduced or equaled to that under wet direct seeding.Therefore,flooded direct seeding could inhibit the germination of P.hydropiper and B.pilosa,there-fore change the community structure of important weeds in paddy fields,as well as control the quantity of E.colo-num,E.crus-galli,C.difformis,L.procumbens,A.aequalis,J.prismatocarpus,P.distichum.
direct seeding methodweeds in paddy fieldcommunity compositionecological niche
万方数据
维普
