Habitat Conditions And N & P Nutrient Contents Of Algae Back Inoculation In Loess Area

The eco-environmental conditions and nitrogen and phosphorus content of artificial cultivation of algae were researched by field sampling and the experiment of solid-phase'inoculated culture of liquid algae species in the laboratory, in order to investigate the influence of different temperatures, different light conditions,different moisture conditions, different nitrogen and phosphorus contents on the growth and reproduction of algae. The main conclusions are as follows:(1)The growth of algae after inoculation to undergo a period of adaptation to the environment, when the experiment of solid-phase'inoculated culture of liquid algae species. In this study, the environmental adaptation of algae was in the 11 d in addition to the experiment on the nutrition, when the algal biomass was continued to decrease and the growth curve was also decline. The algal biomass began to rise when it was 15 d after algae was inoculated.(2)The temperature plays a very important role in the algae tieback, and different temperatures have different influence of the survival, colonization and growth of algae species. The growth of algae showed the fluctuating trend with the time under the high temperature. The fluctuations of the algae growth were less when it was under 20℃and room temperature. The average change rates of algal biomass were 11.2%, 3.57% and 77.5% under 20℃, room temperature and 35℃respectively. The algal biomass under 20℃and room temperature showed significant differences compared with the 35℃(P<0.05) affert the 15 d. The algal growth under 20℃and 35℃started to recovery after the 15 d, which was earlier than the 22 d under room temperature.(3)The light conditions were essential influent factors in the process of algal growth, which factored its growth and reproduction through the influence of algal photosynthesis. The algal growth curve under 60% shading was significantly higher than that under the all-light and less-light conditions. The fluctuations of algal biomass under the low-light conditions was the largest in the all light conditions. The algal biomass under the all-light and less-light conditions showed significant differences compared with the low-light conditions (P<0.01). The algal growth was not significant (P>0.05) under all-light conditions and 80% shading. The light conditions may influence the algal growth by changing the soil moisture. In short, the growth of algal need a proper light condition, and it was not conducive to the algal growth and development when the light was too strong or too weak.(4)The soil moisture conditions was irreplaceable in the growth of algal, which could directly affect the algal colonization and growth after solid-phase inoculated culture of liquid algae species. The biomass of algal under the 30-35% soil moisture level was larger significant than that under the soil moisture content of 8-10% and 20(±1)%. The algal growth curve when the soil moisture was up to 30-35% was significantly higher the other. The fluctuations of algal biomass under the 30-35% soil moisture level was the largest in the all soil moisture conditions. The algal growth curve under the 30-35% moisture level continuously to rise, while it was not recovery when the soil moisture content was 8-10% and 20(±1)%. The algal biomass under the adequate soil moisture conditions showed significant differences compared with the other two water conditions (P<0.01). The algal growth was not significant (P>0.05) when the soil moisture content was 8%-10% and 20(±1)%.(5)The various nitrogen and phosphorus contents had the large or small impact to the algal growth after the solid-phase'inoculated culture of liquid algae species. The nitrogen and amount of standard BG11-medium could promote the growth of algae. The growth of algae under different nitrogen and phosphorus contents was very similar after algae inoculation. The growth of algae when the nitrogen and phosphorus levels were too high (N20 and P10) or zero nitrogen and phosphorus (N0 and P0) content was not seriously inhibited compared with the BG11-medium.