Effects Of Carbon Enrichment And Fertilization On Soil Physicochemical Properties, Physiological Growth, Yield And Quality Of Wine Grapes In The Eastern Foothills Of Helan Mountains

The gravelly neogenetic soil with poor soil structure,low organic matter content and insufficient nutrients of at the eastern foot of Helan Mountain is one of the key factors restricting the coordinated improvement of wine grape yield and quality.A large number of studies have shown that increasing carbon and fertilizing is an effective measure to to improve soil structure,enhance soil water and fertilizer storage capacity,and improve crop yield and quality.In recent years,biochar and nano organic fertilizer have attracted more and more attentions due to the agglomeration of porous structure on soil particles,effective improvement of soil structure,and improvement of nutrient utilization efficiency.In order to further explore the effects of nano organic fertilizer and biochar on soil physical and chemical properties,physiological growth and development,yield and quality of wine grapes,and to analyze the internal mechanism of carbon increase and fertilization on soil structure nutrient utilization yield and quality of wine grapes.In this paper,eight-year-old "Cabernet Sauvignon" is used as the material in Guanlan winery at the eastern foot of Helan Mountain,and nano organic fertilizer and biochar are selected to carry out field positioning experiments with different dosages.According to the analysis of soil aggregate structure and field water capacity,soil nutrients and microbial community characteristics,as well as the physiological growth characteristics of wine grapes under the conditions of carbon enrichment and fertilization,this study explores its impact on soil water retention,nutrient cycling ability,and wine grape yield and quality.A reasonable amount of carbon enrichment and fertilization for the synergistic production and quality of wine grapes in the gravel soil of the eastern foothills of Helan Mountain is proposed to provide theoretical basis and technical support for high-quality cultivation of wine grapes in the eastern foothills of Helan Mountain.The main research findings are as follows:(1)Nano organic fertilizers and biochar can significantly improve soil aggregate structure and other physical characteristics.Compared with conventional fertilization(NPK),under the application of different amounts of nano organic fertilizer,each treatment can increase the total porosity of the soil layer,field water capacity,and reduce the soil surface bulk density.Among them,a significant increase is obtained in the treatment of 70%CK+nano organic fertilizer at 1800 kg/hm2,followed by the treatment of 80%CK+nano organic fertilizer at 1200 kg/hm2.Applying different amounts of nano organic fertilizers can significantly improve the content of soil macroaggregates.Soil silt and clay contents increased under the treatment of 80%CK+1200 kg/hm2,and clay contents increased most significantly Under the application of different amounts of biochar treatment,compared with conventional fertilization(NPK),the content of soil mechanical and water stable aggregates with a particle size of>0.25 mm is significantly increased.Among them,the treatment of 70%CK+biochar 11250 kg/hm2 shows the greatest increase.At the same time,this fertilization amount significantly increases the total porosity of soil surface layer and field water capacity.The mechanical composition of the soil surface is sand>clay>silt.Compared to conventional fertilization,the sand particles on the soil surface are reduced in all treatments,and the soil silt content can increase in all treatments.(2)Nano organic fertilizers and biochar can significantly improve soil nutrients and microbial biomass.Compared with conventional fertilization,the treatment of 70%CK+nano organic fertilizer at 1800 kg/hm2 can significantly increase the content of soil organic matter,alkali hydrolyzable nitrogen,available phosphorus,and available potassium in the 0-20 cm,20-40 cm,and 40-60 cm soil layers.Compared with conventional fertilization,the number of microbial bacteria,fungi,and actinomycetes in the soil topsoil significantly increased,with the highest number of bacteria,followed by actinomycetes,and the lowest number of fungi.Compared with conventional fertilization,the treatment of 70%CK+biochar 11250 kg/hm2 significantly increases the soil nutrient content of 0-20 cm,20-40 cm,and 40-60 cm in the soil layer.However,the treatment of 70%CK+biochar 7500 kg/hm2 showed the most significant increase in soil alkaline nitrogen content at 0-20 cm in the soil layer,,and the treatment of 70%CK+biochar 11250 kg/hm2 shows the most significant increase in the number of soil fungi,bacteria,and actinomycetes compared to conventional fertilization.(3)Nano organic fertilizers and biochar can significantly promote the physiological growth of wine grapes.Different amounts of nano organic fertilizers can significantly increase the new length,leaf area,and root activity of wine grapes at different stages of growth compared to conventional fertilization.Among them,the growth of wine grape new shoots is most significant under the treatment of 60%CK+nano organic fertilizer 2400 kg/hm2 compared to conventional fertilization,and the leaf area and root activity of wine grapes are most significant under the treatment of 70%CK+nano organic fertilizer 1800 kg/hm2.Compared with conventional fertilization,each treatment can increase the chlorophyll SPAD value of wine grapes,and thus increase the net photosynthetic rate,stomatal conductance,and transpiration rate of wine grapes.However,the intercellular CO2 concentration decreases,and it can also increase the daily average net photosynthetic rate,stomatal conductance,and transpiration rate of wine grapes.The daily average intercellular CO2 concentration also decreases,and the most significant increase in physiological indicators of each treatment is the 70%CK+nano organic fertilizer 1800 kg/hm2 treatment.Under different amounts of biochar treatment,at different stages of wine grape production,the treatment of 70%CK+biochar 7500 kg/hm2 shows the most significant increase in new shoot length compared to conventional fertilization.Under the treatment of 70%CK+biochar 11250 kg/hm2,the leaf area and root activity of wine grape reachs their maximum at 0-30 cm of soil layer,with root activity increasing by 80.70%compared to conventional fertilization.Meanwhile,the treatment of 70%CK+biochar 11250 kg/hm2 significantly increases the chlorophyll SPAD value of wine grape at different stages.Thus,the net photosynthetic rate,stomatal conductance,and transpiration rate of different periods and daily averages are increased,while the intercellular CO2 concentration is exactly the opposite,showing a decreasing trend.(4)Nano organic fertilizers and biochar can significantly improve the yield and quality of wine grapes.Under different amounts of nano organic fertilizer treatment,compared with conventional fertilization,the single fruit diameter,single ear weight,single ear length,and yield of wine grapes can be significantly improved.Among them,the single fruit diameter,single fruit weight,and yield are most significantly increased by 70%CK+nano organic fertilizer 1800 kg/hm2 treatment,with increases of 24.53%,16.78%,and 19.84%,respectively.Compared with conventional fertilization,the content of titratable acid in each treatment is decreased,while the content of soluble solids,reducing sugar,total phenols,total anthocyanins and tannins is increased.Among them,the content of reducing sugar,tannins and total anthocyanins significantly increases in the treatment of 70%CK+nano organic fertilizer 1800 kg/hm2,and the content of total phenols significantly increases in the treatment of 80%CK+nano organic fertilizer 1200 kg/hm2.Compared with conventional fertilization,different amounts of biochar treatment can significantly improve the yield and fruit morphology indicators of wine grapes.Among them,the 70%CK+biochar 11250 kg/hm2 treatment shows the most significant increase in single fruit diameter,single fruit weight,single ear weight,and yield of wine grapes,while the 70%CK+biochar 7500 kg/hm2 treatment shows the most significant increase in single ear length of wine grapes.Compared with conventional fertilization,the content of soluble solids in wine grape is significantly increased,and the content of titratable acid is significantly reduced.The tannin,total anthocyanins,and reducing sugar of wine grape is significantly increased under 70%CK+biomass carbon 11250 kg/hm2 treatment,and the total phenol content of wine grape is significantly increased under 70%CK+biomass carbon 7500 kg/hm2 treatment;The treatment of 70%CK+11250 kg/hm2 of biomass charcoal has the greatest impact on improving the quality and efficiency of wine grapes.(5)There is a positive correlation between soil macroaggregates under nano organic fertilizers and biochar,as well as soil organic matter,alkaline nitrogen,available phosphorus,and available potassium content;Soil nutrients are positively correlated with the number of soil microorganisms,grape yield,and quality,with significant positive correlation(P<0.05)and extremely significant positive correlation(P<0.01).In summary,the optimal fertilization amount for nano organic fertilizer is 70%CK+1800kg/hm2 of nano organic fertilizer;The optimal fertilization amount for biochar is 70%CK+11250kg/hm2 of biochar.