Study On The Influence And Its Mechanism Of Sod-culture To Olive's Drought Resistance And Growth

Sod-culture has been practiced in more and more orchards for many benefits,due to its role of regulation in orchard microclimate,improvement in soil organic matter and available nutrient content,enhancent in soil biological activity,reduction in soil erosion,and enhancement in the diversity.Rational use of orchard sod-culture may be beneficial to the yield increase of olive,however,the application of sod-culture was obviously behindhand in olive orchard of our country.In this paper,we studied the bioactivity responses of sod-culture to the rhizosphere soil of olive,the drought resistance of olive leaf,the inflorescence of olive,AMF diversity,aimed at the function evaluation and system optimization of the compound ecosystem in the olive orchard,the application of the sod-culture on the drought resistance and physiological regulation of the olive,the application of mycorrhizal biotechnology in the development of the olive industry,provide a scientific basis for establishing a scientific and reasonable strategy and techniques of sod-culture in olive orchard,revealing the mechanism of sod-culture yield increase.The main conclusions are as follows:(1)Taking the olive orchard with sod-culture as test object,set the sod-culture(both intercropping with hairy vetch(Vicia villosa Roth.)and natural grass mulch)in olive orchard,the soil physical and chemical properties,soil enzyme activities and microorganism number were determinated,to study the effects of sod-culture on the rhizosphere soil microenvironment of olive.The results showed that sod-culture in olive orchard improved the soil water content,alkali-hydrolysable nitrogen content,available phosphorus content,and the activities of the soils urease,phosphatase,invertase activities,the enhancement effect of intercropping hairy vetch was better than natural grass mulch as a whole.Both intercropping hairy vetch and natural grass mulch improved the content of soil organic matter,reduced the soil pH value.Sod-culture in olive orchard increased the number of the soils bacteria,actinomyce and fungi,inhibited the new shoots elongation,and improved the development of short and middle length of bearing branches,this was very beneficial for the improving of the structure of the fruit tree branches.Measure the growth of olive new shoots,flower bud formation rate and the number of flowers per inflorescence to study the effects of sod-culture on the olive floral physiology was discussed.The results showed that the effects of intercropping hairy vetch also improved the flower bud differentiation rate and the number of flower bud per length of the single branch,especially for the bud differentiation rate in short shoot branches.In a word,sod-culture in olive orchard checked the new shoots overluxuriant growth and promoted flower bud differentiation through improving the soils property and the soil fertility level.(2)Six alternative treatments were designed with three sod-culture types(intercropping of hairy vetch,naturally grown grass and clean tillage)and two irrigation types(supplementary irrigation and no supplementary irrigation)in the olive orchard.The effects of sod-culture and supplementary irrigation of olive orchard on the yield and fruit quality indexes were studied.The results showed that sod-culture treatments slowed the water loss of olive leaves under drought stress and increased the water holding capacity of leaves.The chlorophyll a,chlorophyll b and total chlorophyll content of the leaves intercropping hairy vetch and supplemental irrigation was the highest.Natural grass mulch and intercropping hairy vetch both were increased activities of SOD and POD and content of soluble sugar in olive leaf;intercropping hairy vetch were increased the natural proline in olive leaves.The effects of sod-culture and irrigation was more obvious.The intercropping of hairy vetch improved the content of proline in the leaves of olive.The interaction effects of sod-culture and supplementary irrigation treatments on yield per plant,free fatty acid content,total polyphenol content and fruit flesh growth were extremely significant,and the interaction effects on oil content of the fruit and fruit weight were significant.Under the condition of no irrigation,the yield per plant were 8.79% higher in intercropping of hairy vetch than that of clean tillage.Under the condition of supplementary irrigation,the intercropping of hairy vetch and natural grass mulch improved the yield per plant by 10.56% and 5.79%,respectively,compared with clean tillage;Under both the conditions of no irrigation and supplementary irrigation,the fruit weight under the intercropped hairy vetch was significantly higher than the treatmnents of natural grass mulch and clean tillage.(3)Taking potted olive seedlings and rhizosphere soil as the research object,the effects of sod-culture on the AMF diversity in the rhizosphere soil of olive were studied by different sod-culture measures.The results showed that from the four treatments,a total of 19 species of AMF belonging to 4 genera and were isolated in this study.Among them,G.salsum and G.glomus were the dominant genera of AMF in the rhizosphere of olive.Glomus claroideum,Glomus constrictum,Acaulospora foveata,Glomus clarum,caulospora delicate,ntrophospora infrequens could be used as the dominant species of AMF.Sod-culture promoted AMF infection of root system of olive and increased the AMF spore density,species abundance and diversity index,and increased the content of Glomalin and microbial biomass.Overall,the promotion of intercropping Paspalum notatum Flugge was better.In summary,sod-culture enriched the AMF resources of olive rhizosphere.