The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

Climate change 2014 - Mitigation of climate change

This paper presents a review of the turn of events and points of view of biogas in and its utilization for power, heat and in transport in the European Union (EU) and its Member States. Biogas creation has expanded in the EU, empowered by the sustainable power strategies, notwithstanding monetary, ecological and atmosphere benefits, to arrive at 18 billion m3 methane (654 PJ) in 2015, speaking to half of the worldwide biogas creation. The EU is the world chief in biogas power creation, with more than 10 GW introduced and various 17,400 biogas plants, in contrast with the worldwide biogas limit of 15 GW in 2015. In the EU, biogas conveyed 127 TJ of warmth and 61 TWh of power in 2015; about half of absolute biogas utilization in Europe was bound to warm age. Europe is the world's driving maker of biomethane for the utilization as a vehicle fuel or for infusion into the petroleum gas network, with 459 plants in 2015 creating 1.2 billion m3 and 340 plants taking care of into the gas network, with a limit of 1.5 million m3. Around 697 biomethane filling stations guaranteed the utilization 160 million m3 of biomethane as a transport fuel in 2015.

https://www.longdom.org/open-access/biogas-developments-and-perspectives-in-europe.pdf

Biogas Developments and Perspectives in Europe

Recycling of livestock manure to agricultural land may reduce the use of synthetic fertilizer and thereby enhance the sustainability of food production. However, the effects of substitution of fertilizer by manure on crop yield, nitrogen use efficiency (NUE), and emissions of ammonia (NH3 ), nitrous oxide (N2 O) and methane (CH4 ) as function of soil and manure properties, experimental duration and application strategies have not been quantified systematically and convincingly yet. Here, we present a meta-analysis of these effects using results of 143 published studies in China. Results indicate that the partial substitution of synthetic fertilizers by manure significantly increased the yield by 6.6% and 3.3% for upland crop and paddy rice, respectively, but full substitution significantly decreased yields (by 9.6% and 4.1%). The response of crop yields to manure substitution varied with soil pH and experimental durations, with relatively large positive responses in acidic soils and long-term experiments. NUE increased significantly at a moderate ratio (<40%) of substitution. NH3 emissions were significantly lower with full substitution (62%-77%), but not with partial substitution. Emissions of CH4 from paddy rice significantly increased with substitution ratio (SR), and varied by application rates and manure types, but N2 O emissions decreased. The SR did not significantly influence N2 O emissions from upland soils, and a relative scarcity of data on certain manure characteristic was found to hamper identification of the mechanisms. We derived overall mean N2 O emission factors (EF) of 0.56% and 0.17%, as well as NH3 EFs of 11.1% and 6.5% for the manure N applied to upland and paddy soils, respectively. Our study shows that partial substitution of fertilizer by manure can increase crop yields, and decrease emissions of NH3 and N2 O, but depending on site-specific conditions. Manure addition to paddy rice soils is recommended only if abatement strategies for CH4 emissions are also implemented.

Benefits and trade-offs of replacing synthetic fertilizers by animal manures in crop production in China: A meta-analysis

Long-term fertilization causes declines in soil quality and crop yield, hindering current agricultural development. This paper is about the effect of long-term fertilization (20 years) in Hunan’s Qiyang County. It was found that chemical nitrogen, phosphorus, and potassium (NPK) fertilizer lowered soil pH by an annual average of 0.07, while organic fertilizer increased soil pH by about 0.04. Furthermore, organic fertilizer and chemical fertilizer both increased total soil organic carbon (SOC). Long-term chemical NPK and organic fertilizer increased straw and grain yield of wheat and maize to a greater extent than did other fertilization methods. Thus, our results suggest that mixing organic fertilizer with chemical NPK fertilizer should prevent soil acidification and elevate crop yield.

Effects of long-term application of organic fertilizer on improving organic matter content and retarding acidity in red soil from China

The intrinsic processing quality of wheat (Triticum aestivum L.) cultivars is modified significandy by cultural conditions and climate. In an attempt to understand the biochemical basis of such variation, environmental modification of flour protein content and composition was measured. Thirty hard red winter wheat cultivars and experimental lines were grown at 17 Nebraska environments during 1990 and 1991. Environmental conditions, including grain filling duration, temperature and relative humidity during grain filling, were monitored. Grain yield and test weight also were determined as environmental indicators. Significant linear correlations between flour protein content, as measured by near-infrared spectroscopy, were observed only with the duration of grain filling. Protein quality, as measured by SDS sedimentation volumes and size-exclusion high-performance liquid chromatography, was highly influenced by the frequency of high temperatures during grain filling and by the relative humidity. Observed ranges in genotypic responses (variance) at locations also were altered by environmental factors. Optimal protein quality, as determined by SDS sedimentation volumes, was observed with exposure to less than 90 h of temperature greater than 32 °C during grain filling. Protein quality declined with exposure to a greater number of hours of elevated temperature. © 1995 Academic Press Limited

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Environmental Modification of Hard Red WinterWheat Flour Protein Composition

Soil organic matter (SOM) plays an important role in terrestrial ecosystems and agroecosystems. Changes in the agricultural sector in the Czech Republic within the past 25 years have had a negative impact on SOM content and contribute to gradual soil degradation. The aim of this study is to estimate the effect of long-term application of different mineral fertilizers (NPK) and organic manures (manure, cattle slurry) on soil chemical properties (quality of humus, available nutrients, and soil reaction). Soil samples were collected from Luvisol during two selected periods 1994–2003 and 2014–2016 from long-term field experiment carried out in Prague-Ruzyně (Czech Republic). Average annual temperature is 8.5 °C, and annual precipitations are 485 mm. Different fertilization regimes have been applied for 62 years. The crop rotation was as follows: cereals (45%), root crops (33%) and legumes (22%). Soil analysis—soil organic carbon (SOC) was determined by oxidimetric titration method. Short fractionation method for evaluation of humic substance (HS), humic acid (HA) and fulvic acid (FA) content was used. Absorbance of HS in UV-VIS spectral range was measured by Varian Carry 50 Probe UV-VIS spectrometer. Degree of humification (DH) and color index (Q4/6) were calculated from fractional composition data. Soil reaction was measured by potentiometric method. Available nutrients (phosphorus, potassium, magnesium, calcium) were determined by Mehlich II and Mehlich I methods and by ICP-OES. For data analysis, the following are used: exploratory data analysis, ANOVA, and principal component analysis (PCA). PCA analysis differentiated fertilizers into two categories: (1) variant NPK (lower quality of humus)—higher acidity, lower SOC and HS content, predomination of FA, higher DH and lower content of available nutrients; (2) variants with organic manures (higher quality of humus)—lower acidity, higher SOC and HS content, predomination of HA, middle DH, and high content of available nutrients. The main result of presented study is to give a synthesis of effect of different type of fertilizers on a sustainable organic matter management in arable soils, with respect to yields, food security and adaptation to predict climate changes. Long-term application of mineral fertilizers (NPK) without organic matter input can accelerate humus mineralization and soil quality degradation with all negative consequences such as (nitrogen leaching, higher availability of toxic element for plants, slow energy for soil microorganisms etc.). Application of organic fertilizers (manure and cattle slurry) helps to achieve the long-term stable yields while maintaining soil at optimum quality (long-term sustainable management with SOM). Principal component analysis is a useful tool for evaluation of soil quality changes.

The effect of application of organic manures and mineral fertilizers on the state of soil organic matter and nutrients in the long-term field experiment

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.

https://www.mdpi.com/2073-4395/11/4/779/pdf

The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

Research related to the allometric relationships of tree height and projected tree crown area to diameter at breast height was conducted to look at the biological suitability and timber production potential of Douglas fir under the conditions present in central Europe. The dependence of allometric relationships on soil nutrient conditions were described in forest stands of Douglas fir and Norway spruce. The studied sites were climatically similar but differed in soil nutrient availability. A significant difference was found in the allometric relationships of Norway spruce trees from the nutrient poor and nutrient rich site. In contrast to the Norway spruce, there was no significant effect of site fertility on allometric relationships for Douglas fir suggesting that its allocation patterns were less sensitive to site nutrient conditions. Stem growth increment, which was measured weekly during two consecutive seasons for both species, was related to the weather conditions and available soil moisture. Stem growth of Douglas fir began about 2 weeks earlier than in the Norway spruce at both sites. At the nutrient rich site, most of the stem growth of both species occurred at the beginning of the season, while growth at the other site was more evenly distributed throughout the season. Data obtained in this study will be useful for modeling stem growth and analysis of water use efficiency of these two tree species.

Tree allometry of Douglas fir and Norway spruce on a nutrient-poor and a nutrient-rich site

We studied the effect of local weather conditions on intra-annual wood formation dynamics and wood structure of European beech (Fagus sylvatica L.) from a temperate location in the Czech Republic in two consecutive years, 2010 and 2011, characterized by different amounts of precipitation. Microcores were taken at weekly intervals and transverse sections of cambial and xylem tissue were prepared for light microscopic observation. Air temperature and soil moisture content were measured daily at the research plot. Tree-ring formation patterns and vessel features showed different responses to climatic factors in the two years. In 2010, the onset of cambial cell production occurred almost 10 days later than in 2011, when a considerably reduced amount of rainfall was already observed in the winter and spring months, as shown in Standardized Precipitation Index (SPI) values. Lack of precipitation in 2011 caused premature cessation of cambial cell division and markedly narrower annual xylem increments. Vessel density and water conductive area were higher in 2011 than in 2010. Average vessel size in general did not change. In response to local weather conditions, beech controls its hydraulic conductivity mainly by changing the number of vessels and tree growth rate, followed by vessel size. The lower sensitivity of vessel diameter to hydrological alterations confirms previous studies by other authors.

The effects of drought on wood formation in fagus sylvatica during two contrasting years

The paper presented evaluates reserves and chemical composition of forest floor of three stands of Douglas fir, spruce and spruce with beech at acid sites (3K) in the Hůrky Training Forest District (TFD) and at a meso- trophic site (4H) in the Křtiny Training Forest Enterprise (TFE). The aim of the study was to evaluate: ( i) reserves of forest floor, ( ii) soil reaction, ( iii) total content of carbon and nitrogen for the forest floor layers, ( iv) C/N ratio, and (v) the content of dissolved organic carbon (DOC). The lowest reserve occurs in the Douglas fir stand at a mesotrophic site (25.0 t/ha), the highest accumulation occurs in the spruce stand and in the spruce/beech stand at an acid site (79.4-79.6 t/ha). The soil reaction is strongly acid to acid. The most favourable values of pH for forest floor and soil at acid (4.6 ± 0.4) and mesotrophic sites (5.2 ± 0.4) occur in the Douglas fir stand. It also corresponds to C/N ratio (23-26). The highest reserve of carbon in forest floor occurs at the acid site 34.7 t/ha (1.3 t/ha nitrogen). The lowest reserve of carbon in forest floor at the mesotrophic site amounts to 8.5 t/ha (0.4 t/ha nitrogen). The higher content of DOC in stands at acid sites can result in a higher risk of soil acidification.

/pdf/humus-conditions-of-stands-with-different-proportion-of-1ziuewx9ni.pdf

Ladislav Menšík

Papers

The effect of application of organic manures and mineral fertilizers on the state of soil organic matter and nutrients in the long-term field experiment

The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

Tree allometry of Douglas fir and Norway spruce on a nutrient-poor and a nutrient-rich site

The effects of drought on wood formation in fagus sylvatica during two contrasting years

Humus conditions of stands with different proportion of Douglas fir in the Hůrky Training Forest District and Křtiny Training Forest Enterprise.