دراسة تأثير مبيدات حشرية شائعة الاستعمال محليا على الكتلة الحيوية و نشاطها في التربة

الملخص EN

This study aims to identify the effect of different concentrations of pesticides dorspan and decis locally common on the biomass of bacteria, fungi, and activity in the soil during the winter and spring growing seasons 2012 / 2013.

Chosen constant rates of pesticides (half - the same – double) concentrations with samples used to treat the soil and then the results compared.

For each sample and concentration a 10 liter spray machine was used.

The results showed that in addition to pesticides decis and dorspan, the different concentrations used to eliminate agriculture insects had negative effects on vital composition of the soil and consequently also resulted in the inhibition of the process of release of carbon dioxide.These pesticides are not constant and are subject to decomposition by soil microorganisms and thus affect the numbers and activity in the soil.

High concentrations of decis, resulted in decrease of the number of bacteria and fungi with time.

Dorspan also showed a similar effect on the bacteria but less on the fungus.

High concentration also influenced negatively rates of CO2, may be due also to degradation of pesticide toxicity due to this decelerating rates of CO2 release.

This was noticed for all concentrations.

After2-4 weeks of the addition, the effect of concentrations resulted in higher proportion to the amount of CO2 release, which was inversely related to pesticides concentration.

Because the decomposition are vital in the long run, rise of release in the amount of CO2 in the beginning may be more related to the decomposition of organic compounds present in the soil and not for ease of metabolism or use of these pesticides by soil microbes.

Statistical analysis showed that there is a significant effect of the interaction between the type of pesticide and concentration at levels of significance 0.05 and 0.01.