Study On The Diversity Protection And Ecological Control Of Predatory Predators In Rice Fields

To explore the diversity protection of predatory natural enemies in rice fields and improve the ecological control,The community of predatory natural enemies in rice fields was investigated by applying organic fertilizers,constructing high-heterogeneity marginal habitats in rice fields,and interplanting multiple varieties,and the effects of ecological control were of predatory natural enemies in rice fields were evaluated.he results are as follows:1.Controlling effects of organic fertilizer on predatory natural enemies in rice fieldsIn paddy fields with organic fertilizers（RPOM）,the contents of alkali hydrolyzable nitrogen,available phosphorus,total phosphorus,and total potassium in paddy soils were significantly higher than those in conventional fertilizers（RPCF）,and the contents of total nitrogen and organic matter RPOM were significantly higher than RPCF.Field surveys for two consecutive years have shown that the species richness of predatory natural enemies is RPOM is significantly higher than RPCF,and the number of individuals RPOM is significantly higher than RPCF;the number of individuals benefit-harm ratio is significantly higher or significantly higher than that of RPCF.The compound microbial fertilizer significantly improves the soil fertility of rice fields;reduces the number of individuals in the functional groups of rice pests,showing a bottom-up effect driven by soil fertility;significantly improves the species richness and individual numbers of predatory natural enemies,Significantly increase the benefit-harm ratio of the number of individuals,showing a top-down effect.At the same time,it shows that the application of organic fertilizer can be expected to significantly enhance the ecological damage control efficiency of predatory natural enemies.2.The effect of habitat heterogeneity on predatory natural enemies in rice fieldsIn 2017,40 species of predatory natural enemies were collected from high heterogeneity marginal habitat rice fields（HHR）with 1667 heads;30 species of predatory natural enemies were collected from low heterogeneity marginal habitat rice fields（LHR）,with 991 heads.In2018,33 species of predatory natural enemies,1384 were collected from HHR rice fields;34species of predatory natural enemies,1031 were collected from LHR rice fields.In 2017,the species richness of predatory natural enemies in HHR rice fields was significantly higher than that in LHR rice fields;the survey results for two consecutive years showed that the number of predatory natural enemies in a unit plot area was significantly higher than LHR.The N pi value of the individual number benefit-to-harm ratio in HHR and LHR in 2017 were 2.62 and1.33,respectively;in 2018,they were 1.37 and 0.51,respectively.That is,the benefit-to-harm ratio of individuals HHR is significantly higher than LHR.The above results show that artificially constructing highly heterogeneous marginal habitats can increase the system’s potential to conserve predatory natural enemy species,significantly increase the number of individual predatory natural enemies in rice fields,increase the benefit-to-harm ratio,and have a better material basis for pest control,and promote predation The ecological control efficiency of natural enemies on rice pests.3.The effect of intercropping multiple varieties on the control effect of predatory natural enemies in rice fieldsInvestigations at each stage of the growing season of early rice in 2018 show that multiple varieties have no significant impact on the community characteristics of predatory natural enemies such as the species richness and the number of individuals in paddy fields.In2018,the species richness and individual number of predatory natural enemies in multi-variety interplanted rice fields were higher or significantly higher than that of single-variety rice fields.From the analysis of the whole growth period of rice,the N pi value of the individual number benefit-to-harm ratio is that the multi-variety interplanted rice field is significantly higher than the single-variety rice field.It shows that multi-variety interplanting has the material basis to control rice pests more effectively than single-variety planting.It can be expected that the ecological pest control efficiency of multi-variety interplanting is higher than that of single-variety planting.