Improvement of Forage Production Sustainability in the Leningrad Region under Climate Change

The increase of probability and depth of weather anomalies, which is important characteristic of climate change process, leads to higher risk of loss of perennial grasses forage yield, rise of price volatility on forage grain market. Increase of sustainability of dairy production supposes development of adapted to new weather conditions technologies of forage production, which are characterized by different investment and current costs. It generates a need of economic evaluation and comparative analysis of technologies taking into account climate change forecast and need of sustainable forage production guarantee. Purpose of the research project is the development of approaches to assessing adaptive technologies in forage production, increasing of dairy farming sustainability to changes in the external environment, including climate change. We assessed changes in forage production technologies in the Leningrad region of Russia, analyzed the implications of these changes for production and financial performance of dairy farming, proposed and tested methods for determination of the optimum harvesting time of perennial grasses. Special attention is paid to the long-term effects of changing the structure of cows＇ diet--shortening the productive use of animals, which reduces the efficiency of dairy herd use and limits the possibility of expanded reproduction. The primary method of the study is the analysis of milk production statistics in the Leningrad region and the Russian Federation. As a result of the study, the necessity to improve the production and investment planning quality, as well as the use of forecasts during planning of dairy production, is grounded.     

Changes in the Abundance of Vascular Plants under the Impact of Industrial Air Pollution: A Meta-analysis

We applied a meta-analytic approach to improve an understanding of the effects of pollution on the primary productivity of terrestrial ecosystems. We identified 73 data sources reporting changes in the abundance of vascular plants (measured as the percentage of ground cover, biomass per unit area, canopy closure and stem basal area) around 75 polluters located in 18 countries (137 effect sizes). The overall effect was negative but varied among the vegetation layers and types of polluters. The strongest detrimental impact on productivity was due to non-ferrous smelters. The abundance of trees was decreased around both acidifying and alkalifying polluters, whereas the abundance of shrubs and field-layer vegetation decreased only near acidifying polluters. Overall, a decline of vegetation was observed in boreal and temperate forests but not in treeless biomes (deserts, tundra or grasslands). The magnitude of the detrimental effects on trees increased with the duration of the polluters?? impact around acidifying polluters but decreased around alkalifying polluters. Adverse effects on the field layer became more severe with increasing community productivity; in combination with the conclusions of previous meta-analyses, this result indicates that diverse and highly productive communities are likely to be the most susceptible to pollution impacts. In general, the pollution effects on the abundance of vascular plants were less detrimental than the effects on their growth and diversity, indicating that primary productivity in polluted ecosystems is maintained by the preferential growth of several pollution-tolerant species.     

Quantifying effects of simple wheat traits on yield in water-limited environments using a modelling approach

Availability of water for plant growth is a key factor determining plant distribution in natural ecosystems and is the most important limiting factor in agricultural systems. The high environmental and economical cost of irrigation, required to maintain grain yields in water scarce environments, gives an incentive for improvements in water use efficiency of the crop. The objective of our study is to quantify the effects of changes in simple component plant traits on wheat yield under limited water supplies using a modelling approach. The Sirius wheat simulation model was used to perform analyses at two contrasting European sites, Rothamsted, UK and Seville, Spain, which represent major wheat growing areas in these countries. Several physiological traits were analysed to explore their effects on yield, including drought avoidance traits such as those controlling wheat development (phyllochron and grain filling duration), canopy expansion (maximum surface area of culm leaves) and water uptake (root vertical expansion rate and efficiency of water extraction) and drought tolerance traits such as responses of biomass accumulation and leaf senescence to water stress. Changes in parameters that control the effect of water stress on leaf senescence and biomass accumulation had the largest impact on grain yield under drought. The modified cultivar produced up to 70% more yield compared with the control for very dry years. Changes in phenology parameters, phyllochron and grain filling duration, did not improve yields at either site, suggesting that these parameters have been already optimised for climates in the UK and Spain through the breeding process. Our analysis illustrates the power of modelling in exploring and understanding complex traits in wheat. This may facilitate genetic research by focusing on experimental studies of component traits with the highest potential to influence crop performance.     

Substrate quality affects microbial‐ and enzyme activities in rooted soil

The rhizosphere reflects a sphere of high substrate input by means of rhizodeposits. Active microorganisms and extracellular enzymes are known to be responsible for substrate utilization in soil, especially in rooted soil. We tested for microbial‐ and enzyme activities in arable soil, in order to investigate the effects of continuous input of easily available organics (e.g., root‐exudates) to the microbial community. In a field experiment with maize, rooted and root‐free soil were analyzed and rhizosphere processes were linked to microbial activity indicators such as specific microbial growth rates and kinetics of six hydrolytic extracellular enzymes: β‐glucosidase, β‐cellobiohydrolase, β‐xylosidase, acid phosphatase, leucine‐ and tyrosine‐aminopeptidase. Higher potential activities of leucine‐aminopeptidase (2‐fold) for rooted vs. root‐free soil suggested increased costs of enzyme production, which retarded the specific microbial growth rates. Total microbial biomass determined by the substrate‐induced respiration technique and dsDNA extraction method was 23% and 42% higher in the rooted surface‐layer (0–10 cm) compared to the root‐free soil, respectively. For the rooted soil, potential enzyme activities of β‐glucosidase were reduced by 23% and acid phosphatase by 25%, and increased by 300% for β‐cellobiohydrolase at 10–20 cm depth compared to the surface‐layer. The actively growing microbial biomass increased by the 17‐fold in rooted soil in the 10–20 cm layer compared to the upper 10 cm. Despite the specific microbial growth rates showing no changes in the presence of roots, these rates decreased by 42% at 10–20 cm depth compared to the surface‐layer. This suggests the dominance in abundances of highly active but slower growing microbes with depth, reflecting also their slower turnover. Shifts in microbial growth strategy, upregulation of enzyme production and increased microbial respiration indicate strong root effects in maize planted soil.     

Livelihood implications of in situ-on farm conservation strategies of fruit species in Uzbekistan

The aim of this paper is to analyze the impact of a set of interventions related to on-farm/in situ conservation and use of fruit species (cultivated and wild) on farmers’ livelihoods and species diversity in Central Asia. Specifically, a difference-in-differences propensity score matching is used to evaluate the outcome of a development research program in Uzbekistan between 2005 and 2010. Species crop diversity maintained by farmers before and after the project increased as a result of the interventions, showing the efficacy of the interventions promoted by the projects in terms of conservation. Furthermore, innovations provided by the program increased both household propensity of marketing and self-consumption of target fruit. However, the program’s interventions did not seem to impact significantly any of the indicators related to household livelihoods. The short time elapsed between the end of the project and the impact assessment may be too brief to capture any observable impact on livelihoods.     

Bimembrane diffusion probe for continuous recording of dissolved and entrapped bubble gas concentrations in peat

Peatlands are significant sources of the important greenhouse gas CH₄ and generally known as sinks for atmospheric CO₂ through peat accumulation. Accurate measurements of the subsurface concentrations of these gases are of pivotal importance for experimental studies improving our understanding of the dynamics and controls on the exchanges of these gases between peat soils and the atmosphere. In this paper we first briefly outline examples of different probe-based techniques for the determination of subsurface gas concentrations and thereafter we document the development and testing of two different membrane probe systems. Finally we discuss a few applications of the probes and show some results obtained by testing them in the laboratory.     

Pollutants in drainage channels following long‐term application of Mancozeb to banana plantations in southeastern Mexico

The aim of this study was to investigate how long‐term Mancozeb application to banana plantations affects the occurrence of pollutants in drainage‐channel sediment and water under tropical conditions. We estimated the possible accumulation of Mancozeb's principal metabolite ethylenethiourea (ETU), as well as manganese (Mn) and zinc (Zn) as components in channel sediment and water. We took samples during the tropical‐rainfall season and the low‐rainfall season. For sediment samples, we determined the contents of ETU, Mn, and Zn. For water samples, we determined the concentration of ETU. Additionally, we took water samples from a runnel that is the receiving body of hydraulic flow from the system. In both seasons, ETU in the sediment was near the detection limit (0.01 mg kg^–1) and did not show any accumulation. However, Mn in sediment at all sampling sites exceeded the threshold values for aquatic life of 630 mg kg^–1 with values between 635 and 7256 mg kg^–1. The Zn concentrations in sediment varied from 87 to 190 mg kg^–1 and exceeded the threshold values for aquatic life of 98 mg kg^–1 at several sites. Furthermore, we determined an accumulation of these heavy metals in the sediments of the banana‐planted zone in comparison with sediments in pasture reference sites. In contrast to the low concentration of ETU in sediment, its concentration in drainage and runnel water (5.9–13.8 μg L^–1) exceeded the EU threshold value for drinking water (0.1 μg L^–1) by up to nearly 140 times. However, the threshold value for aquatic life was not exceeded. We conclude that long‐term Mancozeb application does lead to a severe accumulation of Mn in sediments and of ETU in surface water. New strategies should be used to control black Sigatoka, including integrated methods of pest control so that long‐term negative effects on the environment can be avoided.     

Polycyclic aromatic hydrocarbons in atmospheric particulate depositions and urban soils of Moscow,Russia

Purpose

The study was conducted to quantify the polycyclic aromatic hydrocarbons (PAHs) accumulation in urban soils from different functional areas via atmospheric inputs with particulate matter.

Materials and methods

PAH concentration and pattern were measured in the particulate matter of snow depositions, in the upper layers of artificial soils from densely built-up areas and in the undisturbed natural soils (Umbric Retisols) from green park area. Samples were collected in 2011–2013 at 58 sites with different traffic activities located at the territory of the Eastern Administrative Okrug of Moscow. The soil samples and filters with particulate matter were extracted by pressurized liquid extraction using Dionex ASE200. Clean-up analyses were performed on SPE cartridges filled with silica gel. Concentrations of PAHs were determined by high-performance liquid chromatography using an Agilent 1100 System equipped with fluorescent detector.

Results and discussion

Mean values of PAH input with snow particles were 45–57 μg/m² for recreational and residential zones, and 140–264 μg/m² for traffic zones. The samples of depositions from different functional areas showed a similar PAH pattern and consisted primarily of 3–4-ring PAHs. Total PAH concentrations in upper layers of artificial soils showed similar mean values of 1.43–2.21 μg/g for all functional zones. The PAH content in soils from the park area was twofold lower than that from the built-up area (0.34–0.63 μg/g), despite equal levels of atmosphere contamination on these territories. The upper layers of natural soils from recreational and traffic zones showed slight differences in PAH content, though PAH input with snow was fivefold higher in the traffic zone. Compared with airborne depositions, soils contained significant amounts of 5–6-ring PAHs.

Conclusions

A high level of soil PAH contamination in urban areas of Moscow, several orders of magnitude higher than the current PAH input to them from the atmosphere, indicates a lack of direct connection of the PAH pool in soils with this source. The high PAH content in the upper layer of constructed soils can be the result of repeated use of materials subjected to a constant technogenic impact for the production of artificial soils.

     

Rapid quantification of humic components in concentrated humate fertilizer solutions by FTIR spectroscopy

Journal of Soils and Sediments - The use of humic substances is under thorough discussion of state-of-the-art agricultural science. They are marketed mostly as concentrated aqueous solutions of...