| The North China Plain is one of the main grain-producing areas in China.While increasing crop yield,the intensive rotation of wheat and corn and the intensive application of chemical fertilizers and pesticides have led to a large decrease in farmland biodiversity,resulting in a single ecosystem structure,soil nutrient imbalance and accumulation of soil harmful substances.It is considered an effective way to increase plant diversity,improve biodiversity of different trophic levels and enhance the function of farmland ecosystem through farmland ecosystem reconstruction.Soil ecosystem plays an important role in maintaining ecosystem stability,and the change of soil fauna community is an important indicator of the change of soil ecosystem function.Therefore,the changes of soil fauna community composition and the diversity and feeding activity of soil fauna under different plant and grassland combinations are studied by artificial planting.Thus,the collaborative development of plant,soil and soil animal can be realized,which can provide theoretical basis for farmland ecosystem reconstruction,farmland biodiversity protection and agricultural sustainable development.We constructed two(T2),four(T4),six(T6),and eight(T8)plant combinations at the edge of the field,respectively.Taking the wheat-corn rotation farmland(CKN)and the abandoned wasteland(CKH)as the control,we explored the effects of different plant and grass combinations on the diversity,feeding activity,and physical and chemical properties of large,small and medium-sized soil fauna.The relationship between plant and grass assemblage and soil fauna community was revealed,and the plant and grass assemblage conducive to the conservation of subsurface soil fauna community was selected,so as to provide technical support for protecting farmland biodiversity and restoring farmland soil health.The main conclusions are as follows:(1)Different combination treatments of planting and grass affected soil physicochemical factors.Compared with CKN,T6 and T8 treatments significantly reduced soil p H and soil ammonium nitrogen and nitrate nitrogen contents.Compared with CKH treatment,T6 and T8 treatment only significantly reduced soil nitrate nitrogen content.Correlation analysis showed that soil p H was negatively correlated with aboveground plant biomass and plant species,and positively correlated with plant coverage.(2)The composition of soil macrofauna community was affected by different plant and grass combinations.For large soil animals,the results of principal coordinate analysis showed that compared with CKH treatment and CKN treatment,T6 and T8 treatment could change soil animal community composition.Univariate analysis of variance showed that T6 and T8 treatments significantly increased the abundance of large soil animals,while other plant treatments showed an increasing trend but the difference was not significant.T6 and CKH treatments had the most significant increasing effect on the population number of large soil animals and reached the highest value in CKH treatment,but the abundance of large soil animals in CKH treatment was less.Correlation analysis showed that the group number of soil macrofauna was significantly positively correlated with aboveground plant biomass and plant cover.The Shannon-Weiner diversity index was significantly positively correlated with both plant abundance and plant cover,and the Margalef richness index was significantly positively correlated with plant abundance.Margalef richness index and Pielou evenness index were significantly positively correlated with plant cover and aboveground plant biomass,respectively.Soil p H and nitrate nitrogen content are the main environmental factors affecting the composition of soil macrofauna community.(3)The composition of small and medium soil animal community was affected by different planting and grassland combinations.For small and medium-sized soil animals,the principal coordinate analysis results showed that T6 treatment could change the community composition of small and medium-sized soil animals compared with CKH treatment and CKN treatment.One-way ANOVA also showed that T6 treatment significantly increased the abundance and group number of small and medium soil animals,while other plant treatments were higher than CKH treatment and CKN treatment,but the difference was not significant.Correlation analysis showed that the abundance of small and medium soil animals was significantly positively correlated with aboveground plant biomass and negatively correlated with plant abundance,the Pielou evenness index was significantly positively correlated with plant abundance,and the abundance and group number of small and medium soil animals were significantly negatively correlated with soil p H,which was the main environmental factor affecting the composition of small and medium soil community.(4)Compared with CKN and CKH treatments,the feeding activity of soil animals can be improved by different planting and grassland combinations,and the highest value is reached in T6 treatment,and the difference is significant compared with CKN treatment,but not significant with CKH treatment.According to different layers of soil,the feeding activity of soil animals of 0～5 cm was higher than that of 5～10 cm.The feeding activity of soil animals was positively correlated with the Margalef richness index and Shannon-Weiner diversity index of small and medium soil animals,and with the number of groups of small and medium soil animals.There was a significant positive correlation between soil animal feeding activity and aboveground plant biomass.Multiple stepped-regression analysis showed that soil p H was the main environmental factor affecting the feeding activity of soil animals,and the feeding activity of soil animals was significantly negatively correlated with soil p H.In conclusion,the marginal herbage belt with different herbage combinations can provide sufficient food sources for soil animals through its complex plant community characteristics and stable habitat conditions,and has higher diversity of soil animals compared with the control treatment.Compared with CKN,the abundance,group number and feeding activity of soil animals were increased.Through the research,we believe that the T6 herbage combination of field edge herbage belt is the most beneficial to the function improvement of farmland ecosystem. |
PDF Full Text Request