Effect Of Regulated Deficit Irrigation On Growth And Microenvironment Of Panax Notoginseng Under Micro-sprinkler Fertilization Condition

Panax notoginseng has high requirements for planting conditions.Unreasonable planting is likely to cause root rot,which causes problems such as the quality and yield of Panax notoginseng.Regulated deficit irrigation has the effect of regulating soil moisture environment and improving crop quality.In this study,the two-year-old Panax notoginseng was used as the research object in the field.Four irrigation levels were adopted in the vegetative growth stage of Panax notoginseng:conventional irrigation CK,T1,T4^T5?50%?_f⁶0%?_f?;T2,T6^T7?40%?_f⁵0%?_f?and T3,T8^T9?30%?_f⁴0%?_f?.Three irrigation levels were set during the flowering stage of Panax notoginseng:conventional irrigation CK,T1^T3;T4,T6 and T8?50%?_f⁶0%?_f?;T5,T7 and T9?40%?_f⁵0%?_f?.In the addition,conventional irrigation were carried out as a control experiment in the seedling stage and the fruiting stage of Panax notoginseng.It can ananalyzed the effects of deficit irrigation on the growth physiological indexes of Panax notoginseng,the soil nutrient content and the micro-environment.We can measure yield and quality of Panax notoginseng to find the best irrigation model.The results showed that:?1?In the vegetative growth stage of Panax notoginseng,with the increase of water deficit,the growth of plant height,stem diameter,leaf length,leaf width and petiole length of Panax notoginseng decreased significantly.In the flowering stage of Panax notoginseng,the plant height change of T1 was 6.00%higher than that of CK,and the plant height increment of T3 was at the lowest value of 2.76 cm.?2?In the vegetative growth stage,when the water deficit increased,the net photosynthetic rate,stomatal conductance and transpiration rate of Panax notoginseng decreased significantly,and the carbon dioxide concentration in the leaves'cells of Panax notoginseng decreased first and then rose.The water use efficiency is highest at this stage.?3?In the vegetative growth stage of Panax notoginseng,with the increase of water deficit,the number of bacteria and actinomycetes showed a significant decrease,and the changes of fungal number,urease,H₂O₂ enzyme and acid phosphatase activity increased first and then decreased.At the flowering stage,at 0-10 cm,the number of bacteria and actinomycetes of T3,T8 and T8^T9 were significantly lower than12.50%¹4.39%and 7.15%-7.61%of CK,and the number of fungi of T9 was the highest;except T2,T3 and T9,the urease of each irrigation mode increased significantly by 15.79%-39.46%.At the fruiting stage,compared with CK,the activity of H₂O₂ of T4 increased significantly 19.76%at 0-10cm.When the depth of the soil layer increased from 0-10 cm to 20-30 cm,the microbial number and enzyme activity in the root zone of Panax notoginseng showed a decreasing law.?4?In the vegetative growth period and flowering stage of Panax notoginseng,the use of mild water deficit to promote root elongation,root surface area and volume increase,promote the absorption and utilization of water,so the yield and quality of Panax notoginseng,and the irrigation water use efficiency were significantly improved;the incidence of T4 was significantly lower than that of CK by 53.42%.A severe water deficit model in the vegetative growth period,and the mild or moderate irrigation during the flowering period was adopted will inhibit the root growth of Panax notoginseng,resulting in a reduction in production and quality of Panax notoginseng.Rehydration during the fruiting period of Panax notoginseng has the effect of improving the water conduction of the canopy and roots.On the condition of the test,under the test conditions,the comprehensive analysis found that the T4 model?50%?_f⁶0%?_f in vegetative stage,50%?_f⁶0%?_f in flowering stage?has improved the soil micro-ecological environment and promoted the growth of Panax notoginseng,photosynthesis and water transport.The yield,quality,and the utilization efficiency of irrigation water of Panax notoginseng were improved.