Effect Of Adding Nitrogenous Fertilizer And Planting Density On The Growth And Physiological Characteristics Of Salvia Miltiorrhiza

Salvia miltiorrhiza has been a common Chinese traditional medicinal material fora long time. Its artificial cultivation area is expanding rapidly as a consequence of theincreasing clinical demand. But there is little research on the theoretical and technicalSalvia cultivation and corresponding practical cultivation techniques. In thisexperiment, Salvia miltiorrhiza Bunge is treated with a split plot experiment consistingof two nitrogenous fertilizer levels and five planting density levels, and throughsurveying and valuing the photosynthetic characteristics and protective enzymeactivity, by investigating the population size, dry matter accumulation （DMaccumulation） and root shoot ratio, to quest the effect of the usage of nitrogenousfertilizer and the planting density on the Salvia growth as well as the inner mechanismduring different growth seasons. These all intend to find and offer techniquesupporting for Salvia high yield and regular planting. The main conclusions are asfollows:1. Under the experimental conditions, effect of nitrogen application rate on drymatter accumulation was greater than density effect: when the amount of applicationof nitrogen is180kg/hm²ï¼ˆN2）, the dry matter accumulation is more, both on andunder the ground, and the average high yield is5709kg/hm²; while N1average yieldis4639kg/hm². So production of N2is higher than N1yield by23%. The averageyield of5kinds of planting density is5115kg/hm², the highest yield is M2while M5is the lowest yield. The production of M2is20%higher than the M5. The maximumyield is N2M2of6207kg/hm². In the case of application of135kg nitrogen perhectare （N1）, M3（12×10⁴P/hm²ï¼‰ is the highest yield of5167kg/hm². Nitrogenpartial factor productivity （PFP） is34kg/kg³8kg/kg. Salvia shoot ratio is about 0.60⁰.65at the late of its growth, greater than pre-shoot ratio, and N2shoot ratio ishigher than N1at the same growth period.2. The net photosynthetic rate of salvia leaf showed a bimodal curve, withobvious "midday depression" phenomenon. In "Midday depression" period, stomaconductance, transpiration rate and atmospheric CO₂concentration all decrease, butphotosynthetically active radiation rises. The main limiting factor of that high fertilizertreatment on the net photosynthetic rate of Salvia is the ultilization efficiency of stomaconductance and instantaneous water. The photosynthetic rate under low fertilizertreatment is caused by non-stoma factors.3. Planting density has a greater impact on photosynthetic characteristics ofSalvia leaf. Photosynthetic rate, transpiration rate and stoma conductance of Salvialeaf decrease with the increasing of planting density while intercellular CO₂concentration will increase. Treatment of N2on photosynthetic characteristics ofSalvia is superior to N1.4. The fastest increasing period of the soluble sugar content of Salvia roots is themonth of8¹0, also the period of the fastest-growing root dry matter, the roots tomaintain a high level of soluble sugar contributing the root growth. Salvia plantingdensity is an important factor affecting physiological metabolism of Salvia. N2canpromote photosynthesis, increase sugar transport and input to the harvested organ,resulting in higher yields. With the increasing levels of nitrogen, the content of freeamino acids in Salvia roots will also increase. Nitrogen fertilizer can increase the levelof starch in Salvia root, and the starch content in root is the highest under N2treatment.5. Planting density too large can disturb the activity of plant antioxidant enzymesystem, decrease the capacity of active oxygen scavenging, deteriorate oxidative stressand aggravate lipid peroxidation. The activity of CAT, SOD and MDA decreases withthe increasing of density level. Suitable density is conducive to Salvia growth anddelay the senescence of late leaves, which is also the main internal factor of increasingSalvia production.6. The mass fraction of nitrogen in different organs of Salvia is that leaves aregreater than stems while stems are greater than roots. The average nitrogen mount ofeach treatment on leaf is13.56g/kg; the mean mass fraction of nitrogen of root in M2is the largest, with an increase of23.1%compared to M4. Salvia has a great amount of nitrogen uptake, the highest uptake groups up to102kg/hm², and differenttreatments averaged on86.7kg/hm². Among the comparison of different densities, theaboveground nitrogen accumulation of M3and root nitrogen accumulation of M2arethe maximum when considered separately.7. Density and nitrogen fertilizer level effect salvia yield synthetically, and alsoaffect the physiological mechanisms of yield formation and distribution of nitrogenabsorption. Experimental results show that the best planting density of purplesalvia（Salvia miltiorrhiza Bunge） is10×10⁴p/hm²¹2×10⁴p/hm², while nitrogenfertilizer is180kg/hm²appropriately.