Enzymatic activity of podzolized chernozem contaminated by pollutants during its detoxification

O. Chernikova¹,*, Yu. Mazhayskiy¹ and L. Ampleeva²

¹Academy of law management of the federal penal service of Russia, Sennaya street 1, RU390036 Ryazan, Russia
²Ryazan State Agrotechnological University named after P.A. Kostychev, Kostychev
street 1, RU390044 Ryazan, Russia

Abstract:

The soil is an indicator of the general technogenic situation. In terms of the scale of pollution, as well as the impact on biological objects, heavy metals occupy a special place among pollutants. One of the priority pollutants are Pb, Cd, Zn, Cu. In assessing the ecological state of the environment, the study of the soil cover plays an important role. The most informative integral characteristics of the biological activity of the soil is the activity of soil enzymes. In a lysimetric experiment with podzolized chernozem, we studied the change in the biological activity of soil in terms of dehydrogenase, catalase, urease, invertase and phosphatase enzymatic activity under the complex influence of heavy metals under conditions of the use of detoxification agents. The soil at the experimental site had the following characteristics: pHKCl 6.2; humus content – 3.2%, P₂O₅-229 mg kg-1, K₂O-250 mg kg^-1of soil. Organic and mineral fertilizers in various combinations were used as detoxifiers. According to the obtained data, the redox enzyme – dehydrogenase and hydrolytic enzymes urease and phosphatase are the most sensitive to soil pollution. The best decontamination effect is obtained when using a system of organo-mineral fertilizers, what contributes to an increase in the activity of soil urease by 3.38 times, invertase – by 2.47 times, phosphatase – by 1.48 times, dehydrogenase – by 1.46 times, catalase – by 1.60 times. Changes in the activity of these enzymes can be used to diagnose the effectiveness of the use of various fertilizer systems on soil contaminated by heavy metals.

Key words:

catalase, dehydrogenase, detoxification, heavy metals, invertase, phosphatase, podzolized chernozem, urease

Effect of organic and mineral fertilizers and land management on soil enzyme activities

L. Balezentiene and E. Klimas

Lithuanian University of Agriculture, Studentų 11, Akademija LT– 53361, Kaunas distr.;e–mail: ligita.balezentiene@lzuu.lt

Abstract:

Sustainable and rational management of agrophytocenoses depends on various bio-indices and methods of application, particularly the development and protection of soil resources (Lai et al., 2002). Among other indices, enzyme activity is proposed as a universal index of soil fertility and contamination (Dilly et al., 2003). To ascertain and to make a comparison of bioactivity variation during the vegetation period, soil (Endophypogleyi-Eutric Planasols-Ple-gln-w, artificial drainage) samples were collected from rotation fields of different fertilizing and farming systems (intensive (IF) and organic (OF)) at the Training farm of the Lithuanian University of Agriculture during 2007–2008. N application stimulated urease and saccharase activity in different farming systems (OF and IF) and fertilizing management (manure and mineral fertilizers). When comparing mean soil bioactivity values of 2 years the highest manure effect was detected in the application year (winter wheat treatment) and conditioned the highest urease (8.21 mg NH +–4N g-1) and saccharase (24.52 mg CG g-1 24 h-1)activity but gradually decreased later. The lowest mean of urease (3.62 mg NH +–4N g-1) andsaccharase (22.07 mg CG g-1 24 h-1) activity occurred in IF soil where mineral fertilizers were applied. Soil bioactivity properties (urease and saccharase activity) were positively correlated with soil nutrients (Corg., Ntotal). Urease and saccharase activity properties reflect changes of fertilizer type and management and thus can be used as bio-indicators of soil fertility.

Key words: