[Degradation dynamics of POPs atrazine in soils under long-term located fertilization conditions].

To evaluate the difference of POPs atrazine degradation dynamics in soils under different fertilization conditions, we set up an analysis method of the atrazine residue in soils and studied residue dynamics of atrazine in soils under a long-term located fertilization conditions. After extracted by surging with acetone, liquid-liquid partition and eluted through florisil, the residue of atrazine in soils was detected by gas chromatogram with 63Ni-ECD. The minimum detectable quantity of atrazine is 6.

[Effects of long-term fertilization on soil microorganism and its role in adjusting and controlling soil fertility].

To clarify the relationships between soil microorganisms and soil fertility under the condition of long-term fertilization, a 12-year fertilization experiment was installed on a fluvo-aquic soil, and the amount of soil microorganisms and the content of soil nutrients were determined and analyzed. The results showed that chemical fertilizers combined with organic manure could significantly improve soil fertility and increase the amount of soil microorganisms. Organic manure was obviously superior to corn straw in improving soil fertility.

[Effects of pesticide-contamination on population size and denitrification activity of denitrifying bacteria in paddy soils].

The effects of pesticide contamination on the population size and denitrification activity of denitrifying bacteria (DNB) were studied with three types of paddy soil (Huangsong paddy soil, red earth paddy soil and purple paddy soil) treated with carbofuran, carbendazim and butachlor for four weeks. The results showed that the population size of DNB in purple paddy soil, Huangsong paddy soil and red earth paddy soil varied in the range of 59.04 x 10(4)-157.

[Degradation of fenpropathrin, phoxim and their mixture by soil microbes].

The degradation rates of fenpropathrin, phoxim and their mixture in un-sterilized soil were much quicker than those in sterilized soil, which indicated that soil microorganisms played a significant role in the degradation process in soil. The half-life (T0.5) in un-sterilized soil was 56.