Nano Iron and Silver Application on Some Biological Indicators Activity in Soil

Even though the various application of the nanotechnology in agricultural practices in the last decade their environmental implications have not been addressed enough. Soil biological activities are among the critical soil quality indices due to the rapid reaction with any changes in the soil condition. Therefor the aim of this study was to evaluate the effect of nano-scaled iron and silver particles on some of biological indices in soil.

The study was designed as a completely randomized factorial with three replicates, nano-scaled iron and silver in five levels (0, 20, 50, 100 and 200 mgkg-1). Treated soils were incubated in 50% field capacity moisture regime at 25 ˚C. After 10, 17 and 30 days of incubation subsamples were taken acidic and alkaline phosphatase activity as well as microbial respiration were measured. 

 The results revealed that nano-scaled iron, nano-scale silver and incubation time significantly (p < 0.01) affected the microbial respiration. The highest microbial respiration was measured (47.33 mgC g-1soil) at 200 mgkg-1 nano-scaled particles after 10 days of incubation. Although the alkaline phosphatase changed during the incubation time, nano-scaled particles and time have no effects on acidic phosphatase during the incubation time. The highest alkaline phosphatase activity (282.2 µg p-Nitrophenol g-1soil h-1) was detected after 10 days in 200 mgkg-1 nano-scaled particles.

The present study demonstrated a significant effect of the nano-scaled particles and time on soil respiration. This effect depended on the concentration and type of the nanoparticles. Soil respiration increased by incubation time. The effect of nano-scaled particles on the enzyme activities depends to the kind of enzyme and nano-scaled particles. Alkaline phosphatase activity affected by nano-Fe although nano-scaled particles and incubation time had no effect on the acid phosphatase activity.