Effects Of Different Seeding Density On Nutrient Absorption And Utilization And Biomass Distribution Of Aleurites Montana Nursery Stock

Designation of five different densities, 10cm×10cm, 15 cm×15 cm, 20cm×20cm, 25cm×25cm, 30cm×30cm, to foster Aleurites montana nursery stock, and study the effects on the biomass, photosynthetic fluorescence properties and nutrient absorption and utilization of Aleurites montana nursery stock, it is expected to provide theoretical basis for Aleurites montana nursery stock fostering.1. Effects of Seeding Density on Photosynthesis of Aleurites montana nursery stockSeeding density has little influence on chlorophyll-a, chlorophyll b, carotenoids, the content of chlorophyll a + b and chlorophyll a/b of the Aleurites montana nursery stock. Aleurites montana nursery stock grow in different density various prominently in July to September, for example, the content of chlorophyll a is 1.413 ~ 2.076 mg/g, D30 is 2.076 mg/g in July, which is significantly different with and the content of chlorophyll b in August, D10 is 0.561 mg/g and D25 is 0.275 mg/g. Seeding density has a certain influence on the photosynthetic rate, transpiration rate and stomatal conductance of Aleurites montana nursery stock, when the plant space is less than 25cm , photosynthetic rate of the unit blade is increasing as the increasing of density; when the plant space is equal or more than 25cm, photosynthetic rate of the unit blade is increasing as the decreasing of density. For example, in July the photosynthetic rate for unit blades, D30 is 12.845 umol/(㎡*s), D25 is 9.657 umol/(㎡*s), D10 is 12.545 umol/(㎡ *s).Therefore take the plant space of 25cm*25cm as boundary; the photosynthetic rate of Aleurites montana nursery stock has obvious difference. In the medium-term of seedling growth, for transpiration rate and stomatal conductance, the low density is greater than high density, while, in the later period, it's opposite.2. Effects of Seeding Density on Chlorophyll Fluorescence Parameters of Aleurites montana Nursery StockSeeding density has little influence on Chlorophyll fluorescence parameters of Aleurites montana nursery stock, while in later period of growth, with the decreasing ofΦPSII, qP and ETR, NPQ, Fv/Fm and Fv/Fo are increasing. But in October, theΦPSⅡ, ETR, Fv/Fm and Fv/Fo of D30 attain the maximum, for example, ETR is 26.78, Fv/Fm is 0.772, Fv/Fo is 3.377, and the minimum NPQ is 0.838 of D30, which shows that in this density, photosynthesis is strong and the light energy loss is petty.3. Effects of Seeding Density on nutrient of Aleurites montana Nursery StockSeeding density has little influence on content of C, N, P, K of Aleurites montana nursery stock, while, in the whole growth period, when the plant space is 30cm×30cm, all content of nutrient elements are in high levels, and in the later growing period, the nutrient content of different parts of D30 are in the highest value; the general rules for various density between different parts of the seedlings is leaf > root > stem; and the sequencing for the five kinds of nutrients is: C > N > P > K >Na.The effects of Seeding density on N absorption rate of Aleurites montana nursery stock is coincided with the absorption of P, that is, as the intense of density, N and P absorption are reduced. For example, in September and October, N absorption rate of D30 is 2.473 and D10 is -0.352, which shows there are significant difference between high density and low density in the later growth period. The absorption rate for D10 and D15 are negative; and Pabsorption of D30 is 8.31*10-5, D10 is 2.18*10-6, 38 times than D10. Seeding density has certain influence on the utilization ratio of N, during the vigorous growing period, the lower density, the higher utilization of N. While, for the utilization of P, during the beginning period, the higher density is helpful for the utilization of P, contrary for the later period.4. Effects of Seeding Density on biomass of Aleurites montana nursery stockSeeding density has no obvious influence on height of Aleurites montana nursery stock, but has certain effect on ground diameter changes, namely: with the decrease of the Seeding density, ground diameter increase. For example, in October, from D10 to D30, the ground diameter increased from 10.4 mm to 13.56 mm. Seeding densities has no obvious regularity effects on diameter ratio of Aleurites montana nursery stock, but in later seedling growth period, the lower density, the higher diameter ratio. In the whole growth period, high diameter ratio variation range is 23 ~ 41. Diameter ratio varies considerably in high density.Seeding density has obvious regularity effects on biomass accumulation of Aleurites montana nursery stock, as the deceasing of density, the root dry weight caves, leaves weight, stem weight and average individual dry weight increased. Take the average plant dry weight in October, for example, D30 is 3.69 times than D10.Seeding density has no obvious effects on the underground/ground biomass of Aleurites montana nursery stock, and both are less than 1, so that the demand for light and competitive ability is strong. Seeding density has little influence on biomass allocation and moisture content of Aleurites montana nursery stock, but various densities of biomass distribution of Aleurites montana nursery stock proportion laws are consistent, leaves > stem > root; different parts of the moisture content: leaves > root > stem; The moisture content in different areas are between 65% ~ 80%. Seeding density has influence on the relative growth rate of the Aleurites montana nursery stock, and the growth rate for scanty plant density is higher than closing planting. Between August and September, the relative growth of D30 reaches the maximum 0.033, while, in September, the relative growth of D10 is the minimum 0.001, which is only 1/20 of D30.To sum up, Seeding density has significant influence on biomass, photosynthetic fluorescence properties, nutrient absorption and utilization of the Aleurites montana nursery stock, also, they are interacted and closely related with each others. The influences of Seeding density on the Aleurites montana nursery stock show that, under the circumstances of 30cm*30cm, all indexes reach the maximum. There for, the adaptive seeding density for Aleurites montana nursery stock is 30cm*30cm.