Agroecological role of biohumus on sod-podzolic soil during irrigation of the rump-timothy grass mixture

It has been established that it is possible to increase the productivity of grasslands on sod-podzolic soil with the introduction of biohumus against the background of irrigation. The optimal variant of the experiment with the introduction of vermicompost at the rate of 8 t/ha. The research results revealed an increase in the content of basic nutrients in the soil by 0.2 … 4 mg/100 g of soil, activation of the cellulose-degrading activity of the soil twice, which was characterized as strong on the Zvyagintsev scale. The content of organic matter in the soil increased to 0.28 t/ha. The plant density increased by 1.5 times, the height – 2 times, the yield of the grass mixture increased on average to almost 5 t/ha, the quality of products improved, which corresponded to the zootechnical norm in almost all parameters. The cost of production amounted to 2.04 rubles/kg, conditionally net income – 3.64 rubles. In the summer of 2019, the research results passed the first year of approbation at Igor VyacheslavovichBelousov LLC on an area of 1.5 hectares. The yield was 4.8 t/ha of dry matter, which is 31% higher than the control option – traditional technology.

Fluxes of greenhouse gases from incubated soils using different lid-closure times

Different sampling times for greenhouse gas measurements have been proposed in many incubation studies. Little is known about effects of closure time on denitrification and nitrification rates from incubation experiments. The objectives of this study were to analyse greenhouse gas (carbon dioxide, methane and nitrous oxide) production from different soils with different times of lid closure and to assess effects of different activation times (defined as additional pre-incubation periods before incubation experiments) on gas emissions from soils. Forty grams of air-dried soil samples (depth 0–10 cm) were incubated in 125-mL jars at 25°C with the addition of glucose and nitrate. The first experiment measured greenhouse gas fluxes at different lid-closure times (40, 80, 120 and 1440 min). The second experiment assessed the effects of different durations of soil activation (0.7, 1.3, 2 and 24 h) on gas emissions. Both were conducted with a completely randomised design, with three replicates per treatment. Our findings showed closure time <1 h or >2 h may cause an underestimate of greenhouse gas emissions. Lengthening activation times resulted in different emission rates consistent with soil characteristics. To measure gas fluxes based on linear regression would require four or five sampling points and sampling at a 20-min interval over a maximum period of 80 min for estimating gas fluxes from soil. Because pre-incubation time is critical and a driving factor in the measurement of soil-induced gas emissions, a standardised procedure to quantify gas fluxes is needed for application to other soils.

Adsorption and Deactivation of Atrazine and Diuron by Charcoals

The adsorption of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) from aqueous solution by charcoal varied widely with the type of charcoal tested. However, adsorption in solution was directly related to the deactivating properties of the charcoals for the two herbicides in soil. Several charcoals deactivated residues of 0.3 ppmw of atrazine and 1.0 ppmw of diuron when they were present at concentrations of 30 to 50 ppmw in the soil. Activation of the charcoal was essential for the adsorption and deactivating properties. A simple laboratory test was developed for assessing activated charcoals for use in deactivation studies in soil.