Temperature Sensitivity (Q10) of Soil Basal Respiration as a Function of Available Carbon Substrate,Temperature, and Moisture

Eurasian Soil Science - Basal respiration is one of the key indicators of soil C mineralization. Temperature sensitivity (Q10) of basal respiration is important for predicting changes in C...     

Black currant response to foliar fertilizers – modeling of varietal growth dynamics

Abstract

Black currant cultivation is in continuous expansion, with importance in human nutrition and a high degree of suitability for industrial processing. The nutritional, organoleptic, and pharmaceutical qualities of its fruits represent a great source of natural antioxidants, vitamins, and phenols. We have tested the specific reaction of three black currant varieties to foliar fertilizers in order to obtain two growth models. Each variety have a specific response to fertilizers. Application of Kombimax lead to the highest increase during the vegetation period and 72?cm length of branches at the end of vegetation period. Ascovigor and Mikromix produces 3–4?cm increases in branches length compared to control. N, K2O, and CaO from fertilizer recipe act synergically for the final development of branches. The growth model based on branches length at 14?days add 0.97?cm for each existent cm. The complex model of growth add 2.44?cm for each mg of CaO existent in fertilizer recipe. Linear regressions show a growth potential of 0.97?cm/1?cm of branches at 14?days.     

Use of sodium polytungstate in the granulo-densimetric fractionation of soil material

A solution of sodium polytungstate (SPT) is used as a heavy liquid in global soil studies. This reagent has found wide use because it is nontoxic, incombustible, well soluble, environmentally safe, and of low viscosity. There is a relatively simple and accessible method for its regeneration. The reagent contains no carbon compounds, which is important for studying organic matter with the use of carbon isotopes. However, some chemical properties of SPT should be taken into consideration to ensure the obtainment of incoherent and sorbed solid-phase forms of organic matter. A modification of granulodensimetric fractionation is described that allows separating the solid-phase fractions of soils without changes in the content and isotope composition of the organic carbon and organic nitrogen in the separated material.     

Effect of the natural reforestation of an arable land on the organic matter composition in soddy-podzolic soils

The dynamics of the organic matter composition in soddy-podzolic soils during the natural reforestation of an arable land in the southern taiga zone have been discussed. It has been shown that the contents of the total and labile carbon in the old plow horizon increase with the age of the fallow in the chronosequence of soils established in the Parfen’evo district of Kostroma oblast. The parameters characterizing the labile soil organic matter include the contents of the carbon extractable by mild chemical extractants (distilled water, 0.1 M K₂SO₄ solution, 0.1 M neutral Na₄P₂O₇ solution), the microbial biomass, and the light fraction. The granulo-densimetric fractionation has shown that the contents of carbon in the light and organomineral fractions of the soil vary in the course of the postagrogenic succession. The content of the clay-fraction carbon increases and its portion in the total carbon of the soil decreases at the transition from the plowland to the forest. The reforestation of agrosoddy-podzolic soils enhances the physical protection of the soil organic matter due to the increase in the portion of microaggregate carbon.     

Solubility of the labile forms of soil carbon and nitrogen in K2SO4 of different concentrations

The general pattern of the changes in the solubility of the labile carbon and nitrogen compounds with the changes in the concentration of the salt extractant (0.05 and 0.5 M K₂SO₄) has been determined for soils differing in their acidity and in their contents of organic matter and nitrogen. Different forms of extracted compounds react differently to changes in the salt concentration. The solubility of inorganic nitrogen compounds (NH ₄ ⁺ and NO ₃ ^? ) does not depend on the concentration of K₂SO₄. In most cases, the carbon and nitrogen of the microbial biomass manifest a tendency for increasing extractability with an increase in the concentration of the K₂SO₄ solution. A fundamental difference is characteristic of the organic carbon and nitrogen compounds, the solubility of which in 0.5 M K₂SO₄ increases in different soils by 1.5–3.9 times in comparison with their solubility in 0.05 M K₂SO₄.     

Acidification and nutrient imbalance in forest soils subjected to nitrogen deposition

Emission of nitrogen oxides (NO_x) and ammonia (NH₃) from a fertilizer factory and the resulting input of nitrates (NO₃ ^?) and ammonium (NH₄ ⁺) into the soil were the main reasons of nitrogen (N) cycle disturbance in forest ecosystems near Novgorod, North-Western Russia (50°31′ North, 31°17′ East). Total N atmospheric input was about 100 kg/ha annually. NH₃ was a dominant pollutant, causing the increase of atmospheric precipitation pH within the polluted region compared to background territories (6.0–6.5 and 4.5–5.0, respectively). Soil acidification through NH₄ ⁺ nitrification was observed. N-NO₃ ^? concentrations in soil solution reached 20–30 mg/l, and proton (H) production was equal to 4.1 keq/ha per warm season (from April to October). Compared with soil status in 1983, pH decrease by 0.2 pH units was found in A horizon. The content of exchangeable calcium (Ca) and magnesium (Mg) decreased by the factor of 2–3 and 1.5–2 in A and B horizons, respectively. Triple increase of exchangeable aluminium (Al) content was detected in A horizon. Through recent decrease of pollutant emission, the polluted territory is now a suitable subject for recovery studies.     

Phosphorus status of Eutric Cambisols polluted by P-containing immissions: Results of 31P NMR spectroscopy and chemical analysis

The P status of an unpolluted Cambisol was compared with that of a polluted Cambisol receiving high P deposition that arise from a fertilizer factory near Novgorod, NW Russia. Experiments included P fractionation, P adsorption experiments and ³¹P NMR spectroscopy. In the O, A and AB horizons of the unpolluted soil organic P was the dominating fraction. Anthropogenic P accumulation was restricted to the O, A and AB horizons and amounted 692 kg ha^?1, representing the sum of P deposition within 20 years of factory operation. Most of the additional P was extractable inorganic P. Hence, P extractability increased from 54-75 % in the unpolluted soil to 66-83 % in the polluted soil. Ca-phosphates were mainly accumulated in the forest floor, while Al- and Fe-phosphates were concentrated in the A and AB horizons. Organic P showed only a slight increase due to P deposition. This increase was only due to accumulation of stable monoester-P, while the stock of the more labile diester-P and phosphonates in the polluted soil was only half of that in the unpolluted soil.     

The nitrogen isotopic composition in soils and plants: Its use in environmental studies (A Review)

The results of studying the isotopic composition of the nitrogen in soils and plants and its use for characterizing the nitrogen cycle in ecosystems, the transformation of nitrogen compounds in soils, the sources of nitrogen nutrition for plants, and the assessment of the symbiotic nitrogen fixation’s contribution to the nitrogen budget of ecosystems were considered for a wide variety of natural and agricultural ecosystems.