Aims Understanding the response of farmland weed community assembly to fertilization is important for designing better nutrient management strategies in integrated farmland ecological systems.Many studies have focused...Aims Understanding the response of farmland weed community assembly to fertilization is important for designing better nutrient management strategies in integrated farmland ecological systems.Many studies have focused on weed characteristics,mainly crop–weed competition responses to fertilization or weed communities alone.However,weed community assembly in association with crop growth is poorly understood in the agroecosystems,but is important for the determination of integrated weed management.Biodiversity promotes ecosystem productivity in the grassland,but whether it applies to the agroecosystems is unclear.Based on an 11-year field experiment,the cumulative effects of different fertilization patterns on the floristic composition and species diversity of farmland weed communities along with wheat growth in a winter wheat–soybean rotation were investigated.Methods The field trial included five fertilization patterns with different combinations of N,P and K fertilizers.Species composition and diversity of weed communities,aboveground plant biomass and nutrient accumulation of weeds and winter wheat,light penetration to the ground surface and wheat yield were measured at each plot in 2009 and 2010.Multivariate analysis,regression and analysis of variance were used to analyze the responses of these parameters to the different fertilization treatments.Important Findings Four dominant weeds(Galium aparine L.,Veronica persica Poir.,Vicia sativa L.and Geranium carolinianum L.)accounted for~90%of the total weed density in the 2 years of experimental duration.The residual weed community assembly was influenced primarily by topsoil available nutrients in the order P>N>K.Competition for nutrients and solar radiation between crops and weeds was the main indirect effect of fertilization on the changes in weed community composition and species diversity.The indices of species diversity(species richness,Shannon–Wiener,Pielou and Simpson indices)showed significant linear relationships with wheat yield.The balanced fertilization treatment was more efficient at inhibiting the potential growth of weeds because of solar radiation being intercepted by wheat.These results support the conclusion that wheat yield is favored by balanced fertilization,whereas the weed community is favored by PK fertilization in terms of density and diversity.However,the negative effects on wheat yield may be compromised by simultaneous positive effects of weed communities in the fertilization treatments,for instance,the NP and NK treatments,which are intermediate in terms of increasing wheat production and to a level maintaining a diverse community.展开更多
A long-term fertilized paddy field under rice/rape rotation in the Taihu Lake Region was selected to investigate the dynamics of soil weed seed diversity.Four fertilizer treatments were performed,including non-fertili...A long-term fertilized paddy field under rice/rape rotation in the Taihu Lake Region was selected to investigate the dynamics of soil weed seed diversity.Four fertilizer treatments were performed,including non-fertilizer(NF),chemical fertilizer only(CF),chemical fertilizer combined with pig manure(CMF)and chemical fertilizer plus crop stalk(CSF).We recorded the seed numbers and crop yields,estimated the weed seed bank density and identified the kinds of weed seeds in the top-soil(0-15 cm)in the study area using a stereomicroscope.Based on the records,we analyzed the effect of long-term fertilization on soil weed seed bank diversity and the rela-tionship between weed seed diversity and crop yields.Comparing the four treatments,it was found that in the cultivating seasons of both rice and rape,the density of soil weed seed bank was the lowest with the treatment of chemical fertilizer plus crop stalk.Whereas,the total number of species and the weed seed bank diversity was the highest.Furthermore,the crop yields were at maximum and kept constant with this treatment.There was a definite correlation between fertilizer treatment and soil weed seed bank diversity and crop yields.It was concluded that balancing the fertilizer management was helpful in main-taining soil weed seed bank diversity,increasing crop yields and alleviating crop yield fluctuation.Therefore,among the four fertilizer treatments,chemical fertilizer plus rice crop stalk treatment was the best one to stimulate the productivity of agricultural ecosystems and simulta-neously protect biodiversity.展开更多
基金China Program of International Plant Nutrition Institute(IPNI-HB-34)the Opening Project of Hubei Key Laboratory of Wetland Evolution&Ecological Restoration(2011-02).
文摘Aims Understanding the response of farmland weed community assembly to fertilization is important for designing better nutrient management strategies in integrated farmland ecological systems.Many studies have focused on weed characteristics,mainly crop–weed competition responses to fertilization or weed communities alone.However,weed community assembly in association with crop growth is poorly understood in the agroecosystems,but is important for the determination of integrated weed management.Biodiversity promotes ecosystem productivity in the grassland,but whether it applies to the agroecosystems is unclear.Based on an 11-year field experiment,the cumulative effects of different fertilization patterns on the floristic composition and species diversity of farmland weed communities along with wheat growth in a winter wheat–soybean rotation were investigated.Methods The field trial included five fertilization patterns with different combinations of N,P and K fertilizers.Species composition and diversity of weed communities,aboveground plant biomass and nutrient accumulation of weeds and winter wheat,light penetration to the ground surface and wheat yield were measured at each plot in 2009 and 2010.Multivariate analysis,regression and analysis of variance were used to analyze the responses of these parameters to the different fertilization treatments.Important Findings Four dominant weeds(Galium aparine L.,Veronica persica Poir.,Vicia sativa L.and Geranium carolinianum L.)accounted for~90%of the total weed density in the 2 years of experimental duration.The residual weed community assembly was influenced primarily by topsoil available nutrients in the order P>N>K.Competition for nutrients and solar radiation between crops and weeds was the main indirect effect of fertilization on the changes in weed community composition and species diversity.The indices of species diversity(species richness,Shannon–Wiener,Pielou and Simpson indices)showed significant linear relationships with wheat yield.The balanced fertilization treatment was more efficient at inhibiting the potential growth of weeds because of solar radiation being intercepted by wheat.These results support the conclusion that wheat yield is favored by balanced fertilization,whereas the weed community is favored by PK fertilization in terms of density and diversity.However,the negative effects on wheat yield may be compromised by simultaneous positive effects of weed communities in the fertilization treatments,for instance,the NP and NK treatments,which are intermediate in terms of increasing wheat production and to a level maintaining a diverse community.
文摘A long-term fertilized paddy field under rice/rape rotation in the Taihu Lake Region was selected to investigate the dynamics of soil weed seed diversity.Four fertilizer treatments were performed,including non-fertilizer(NF),chemical fertilizer only(CF),chemical fertilizer combined with pig manure(CMF)and chemical fertilizer plus crop stalk(CSF).We recorded the seed numbers and crop yields,estimated the weed seed bank density and identified the kinds of weed seeds in the top-soil(0-15 cm)in the study area using a stereomicroscope.Based on the records,we analyzed the effect of long-term fertilization on soil weed seed bank diversity and the rela-tionship between weed seed diversity and crop yields.Comparing the four treatments,it was found that in the cultivating seasons of both rice and rape,the density of soil weed seed bank was the lowest with the treatment of chemical fertilizer plus crop stalk.Whereas,the total number of species and the weed seed bank diversity was the highest.Furthermore,the crop yields were at maximum and kept constant with this treatment.There was a definite correlation between fertilizer treatment and soil weed seed bank diversity and crop yields.It was concluded that balancing the fertilizer management was helpful in main-taining soil weed seed bank diversity,increasing crop yields and alleviating crop yield fluctuation.Therefore,among the four fertilizer treatments,chemical fertilizer plus rice crop stalk treatment was the best one to stimulate the productivity of agricultural ecosystems and simulta-neously protect biodiversity.