Effects Of Lime And Film On Cadmium Accumulation,Physiological And Biochemical,Yield And Quality Of Peanut In Cadmium Contaminated Rice Fields

Cadmium pollution is an important environmental and ecological factor that affects the health and safety of rice in Hunan,which has aroused great concern of the whole society.Through the rice field restructuring,paddy fields to dry farming,is expected to reduce cadmium pollution in agricultural products.Peanuts are rich in protein and vegetable oil and cash crops,the damage status and mechanism of cadmium stress on peanut in paddy field is not yet clear.In this experiment,09-3106 large-seeded peanuts were used as test materials,and six kinds of lime application and coating were designed with 4 groups of lime and cap membrane respectively,The paddy soils of the middle cadmium pollution(0.7 mg/kg)in the Rongheqiao Village,Beishan Township,Changsha County were the experimental sites.The effects of cadmium contaminated rice on the growth and development of peanut,dry matter quality,chlorophyll content,antioxidant enzyme activity,soil p H,cadmium content and yield and quality of various organs were studied,Responses of lime and film mulching to cadmium content and cadmium absorption in peanut soil,explore the best way to cultivate peanut in cadmium contaminated rice fields,in order to provide the theoretical basis and technical reference for the high yield,high efficiency or ecological restoration of peanut in cadmium contaminated rice.(1)Growth and development Increasing the amount of lime applied to the cadmium contaminated rice field peanut pod and maturing stage of the morphological indicators and dry matter accumulation of a small increase,pod dry weight increased significantly,are applied lime 100 kg / mu treatment the highest,indicating that the application of lime to a certain extent to promote the growth of peanuts,for peanuts to increase production to lay a good foundation.Cover film is relatively no cover film treatment,the morphological indexes and dry matter accumulation were significantly increased after seedling stage.Comprehensive comparison of lime application rate of 100 kg / mu and assisted cover film can promote the best growth and development of peanuts.(2)Physiological and biochemical the increase of lime application rate increased the chlorophyll content in podding stage,cover film treatment in addition to podding period,than not cover the film high,indicating that the application of lime in the peanut results can improve photosynthesis,cover the film is to further improve the chlorophyll production,and thus protect the peanut yield.With the increase of lime application rate,the activities of SOD,POD and CAT were decreased in different degrees,cover film treatment are lower than not cover film,indicating that the application of lime to reduce the cadmium damage to the leaves,to reduce their own clearance,the content of malondialdehyde(MDA)was decreased at maturity,and the cover film is lower than the non-cap film treatment,are in the application of lime 100 kg / mu the lowest content.Comprehensive analysis,the application of lime can improve the photosynthetic capacity,reduce the formation of toxic substances,the use of lime 100 kg / mu and cover the film is the most appropriate improvement measures.(3)Soil p H and cadmium content The contents of cadmium,the enrichment coefficient and the total absorption rate of peanut were decreased in different degrees,and the contents of cadmium were root> stem and leaf> pods > seed kernel,with lime 100 kg / acre treatment minimum,indicating that the application of lime test soil acidity decreased,effectively reduce peanut absorption of cadmium content,improve the safety of peanut feeding.Cover film than the non-cover treatment cadmium content,enrichment coefficient,total cadmium accumulation and absorption rate decreased to varying degrees,indicating that the cover film to improve peanut production,while reducing the amount of cadmium adsorption.(4)Yield and quality With the increase of lime application,there are different effects of increasing the number of full pod,reducing the number of edible pod,increasing the yield,oil content,protein content and linoleic acid,and the best in lime 100 kg / mu,While the yield and quality of the coated film were significantly improved.In conclusion,the application of lime and cover film on cadmium contaminated rice field peanut growth and development of late,photosynthesis have a certain role in promoting,reduce the total amount of harmful substances in cadmium stress,and improve the yield and quality while significantly reducing the cadmium adsorption capacity of peanut organs.Comprehensive analysis,peanut in cadmium contaminated rice field application of lime amount of 100 kg / mu and auxiliary cover film for the best ecological restoration measures.