Screening Of The Effects Of 8 Orchard Swards On Weeds,mango And Soil

Cleaning and weeding is still the main way to deal with grass in many orchards.Clean tillage can effectively reduce the number of weeds,reduce the harm of competition for fertilizer and aqueous,and make the orchard soil loose,making the orchard look cleaner and more beautiful.However,long-term implementation of clear tillage system not only takes time and effort,but also causes serious damage to soil physical and chemical properties and soil structure,rapid reduction of organic matter and various mineral nutrient elements,seriously affecting the root growth and yield of fruit trees.And quality.Over the years,more and more research has been done on Weeding in orchards in China,and the benefits have emerged.It has a very good effect on the improvement of orchard soil,orchard microclimate and grass in orchards.Many orchards are planted with grass,which turns the disaster of grass into a harvest of grass.Hainan is a big tropical fruit province in China,but this advanced orchard management model has not been implemented in the orchard,and no research has shown that it is suitable for mango orchards in Hainan.Therefore,it has become a hot topic to select suitable grass species and formulate grass-growing model according to local conditions.In this paper,8 kinds of common grass(Stylosanthes、Paspalum notatum、Poa annua L.、Arachis pintoi、Axonopus compressus P.、Vicia villosa Roth、Festuca elata Keng ex E.、Vulpia myuros C.Gmelin)were used as primary screening varieties,and their weed suppression effects,stress effects on fruit trees and soil improvement were discussed.1、The results showed that the seed germination rate and germination index of the two receptors were significantly inhibited by 8 kinds of swards,and the most significant inhibiting effect was at the concentration of 40 mg/mL.The inhibiting effect of aqueous extract of Paspalum notatum on seed germination rate of Cynodon dactylon and Bidens pilosa increased with increasing concentration,showing a "dose effect".Stylosanthes,Axonopus compressus,Poa annua,Festuca elata and Vulpia myuros all promoted the germination rate of seeds of Cynodon dactylon and Bidens pilosa at the concentration of 5 mg/mL,showing the allelopathic effect of "low concentration promoting high concentration inhibition".When the concentration was 10,20 and 40 mg/mL,eight kinds of grass had very significant inhibitory effects on the stem length and root length of the seedlings of Cynodon dactylon and Bidens pilosa.The effect was not significant when the concentration was 5 mg/mL.The allelopathic effects of Paspalum notatum,Poa annua,Arachis pintoi,Vicia villosa,Festuca elata,Festuca arundinacea were negative in all treatments,while the allelopathic effects of Stylosanthes and Axonopus compressus were positive at 5 mg/mL.2、Compared with the control group,the activities of SOD POD CAT of man go fruit trees treated with 8 kinds of herbage all increased,among which Paspalum notatum increased the activities of POD,SOD and CAT by 34.66%,45.59%an d 43.88%respectively.Stylosanthes had the lowest promotion effect,and the three enzymes activities were not increased more than 30%.When the chlorophyll content of leaves was measured,it was found that the chlorophyll content of mango seedl ings treated with 8 kinds of swrods had a reduced effect compared with the contro 1 group.Among them,Paspalum notatum Arachis pintoi,Vulpia myuros and Poa a nnua had the most significant reduction effect.Compared with the control group,the content of MDA in the seedlings of eight kinds of mango fruit trees treated with herbicide had an increasing effect,among which Bahia grass had the most significant effect,while Stylosanthes had no significant effect.The powder of 8 kinds of swords had certain stress effect on Mango seedlings,among which Paspalum notatum had the most significant effect and Stylosanthes had the lowest effect.3、The fertilizer efficiency of the soil was improved by 8 kinds of grass,and the organic matter content of the soil after 8 kinds of grass treatment was signific antly higher than that of the control group.The increase rates of tall fescue,fescue and vetch were more than 60%.The soil urease activity of tall fescue,Pingtuola opintoi,Poa pratensis,Stylosanthes,Vicia villosa,Oilgrass and Bahia grass treatm ents increased significantly compared with the control group.Only the soil urease activity of fescue grass treatments decreased.The activities of soil catalase in tall fescue,Pingtuolao pintoi,Poa pratensis,Stylosanthes,Vicia villosa and treatment groups were significantly increased compared with the control group(P<0.05),while the activities of soil catalase in the treatment groups of Festuca arundinacea,Oleaceae macrophylla and Bahia grass were not significantly affected,among which Stylosanthes treatment group had the greatest improvement rate compared with the control group.The sucrase activity of tall fescue,fescue,Kentucky bluegrass and ole aginous grass treatments had no significant effect on the soil compared with the control.Pingtuolao pintoi,Stylo grass,villous vetch and Bahia grass all had significa nt improvement.Among them,Bahia grass had significant improvement on soil invertase activity and soil available N,among them,Pingtuolao pintoi had significant improvement on soil available N.Effective N increased by 44.24%,while Stylosant hes and Vicia villosa increased by 37.41%and 42.12%,respectively.Poa pratensis had the highest increase rate(40.05%)among the grasses.There was also a signi ficant increase in available P 8 species of grass,of which 3 leguminous species had an increase rate of more than 50%.Eight kinds of grass had significant increase in soil total N.Among them,vetch had the highest increase in soil total N by 32.46%,while pintoi and Stylosant had 35%and 18.75%respectively.Poa pratensis had the highest increase rate(28.76%)among the grasses.For all P 8 species of grass,the increase rate of three leguminous species was more than 30%.