The Influence Of Soil Algae On Index Of Soil Quality

This paper first reports the difference of soil algae community makeup, microorganism amount, and soil phosphate activity between leanness soils and richness soils. The research soil samples are from Maoxian and from Sichuan University especially. The results show that the two kinds of soils differ greatly in soil algae population, microorganism number and soil phosphate activity. The each kind of soil has it's own different dominant algae genus and relative density.Then, the author carried out the later experiment based on the results of former to study the influence of soil algae on soil quality. This experiment included two steps. In the first step, quantitative and qualitative characteristic of soils influenced by soil microalgal were studied in this step. In this study, four different algal (Chroococcus, Chlorococcum, Navicula and Chalmydomonas) and one algal mixture, which were formed by the above four algal species, were cultivated in two different mediums (soil and double distilled water), under regular illumination or dark condition respectively. Weestimated the environmental pH, the microorganism biomass (not including algal), and the organic matter content very 20 culture days and estimated the available phosphorus after 60 culture days. We got the results by making graphs and extreme-difference analysis after 0, 20. 40 and 60-days cultivation. The results show that there are some similarities among the three data. The influence of the algae difference on the environmental pH changing and the microorganism biomass rising are stronger than those of the medium and illumination differences. The influence of the medium difference on the environmental organic matter content is stronger than those of the algae difference and the illumination difference. And the three data changing in soil are more obvious than in water. The amount of available phosphorus in the soil with algae in it changed much. The influence of the algae on available phosphorus in soil was significant. The algae multiplied massively in suitable environment, and made the amount of available phosphorus in soil increase significantly. The influence of the base matter on available phosphorus in soil was much more significant.In the second step, Nostoc Commune and Chlamydomonas sajao Lewin were inoculated of different inoculation quantities to the barren soils. The soil phosphate activities were determined after 0, 10, 50, 60 days. The results show that alkaline phosphate activity was degressive, acidic phosphate activity changed inconsistently and neutral phosphate activity was ascending slowing. The analyse of the phosphate activity's absolute change also shows that the influence of soil algae on phosphate activity is not prominent.So, we need design farther experiments to study the relation between soil algae and soil phosphate activity.