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The nitrogen mineralization capacity of soils characterizes the rate of organic nitrogen-containing compounds decomposition and reflects their ability to accumulate mobile mineral nitrogen, an objective indicator of the availability of this major nutrient to plants. We have studied gray forest soil (Luvic Greyzemic Phaeozem), widespread among Siberian crop fields, using laboratory (composting under optimal conditions) and field (fallow under natural conditions) techniques to get new agrochemical data on the quantitative and qualitative changes in soil nitrogen compounds and nitrogen-containing fertilizers. The decomposition kinetics of available nitrogen and its release from plant residues (melilot, rapeseed, winter rye, and straw) during the interaction with gray forest soil are determined. The CO2 emission, nitrogen content in microbial biomass, cellulolytic bacterial activity, and accumulation of mineral nitrogen species have been monitored. The role of plant biomass in maintaining the nitrogen status in field agrocenoses is experimentally shown.

Mineral and organic fertilizers have great potential to enhance crop yields in low fertility soils of the Buganda catena. However, the need for site-specific knowledge on use and yield of the two fertilizer types in a complex soil scape is acute among smallholder farmers exploiting any soil differences. This study evaluated on-farm grain yield response of common bean (Phaseolus vulgaris L.) to organic and mineral N and P fertilizers on three soils. Treatments included poultry manure at 0, 2.5 and 5.0 t ha-1, and N and P each at 0, 7.5, and 15 kg ha-1 in a complete factorial for two rainy seasons on each of the local farmers’ soils classified as Phaeozem, Cambisol, and Umbrisol. Fertilizer application resulted in 20, 25 and 36% maxima grain yield increase relative to soils (Phaeozem, Cambisol and Umbrisol soil, respectively) potentials when no nutrient inputs is applied. Mineral fertilizers applied separately reduced yield on the Cambisol while on Umbrisol soil, there was no particular increase; hence these were risky applications on highly degraded soils. Yield increases were greater with manure, with or without mineral fertilizers, but yield increase was not particularly fundamental on Phaeozem sites but was on Cambisol and marginal on the Umbrisol, resulting into positive and negative interaction effects, respectively. Thus, soil specific rates of manure nutrient ratios or with N and P mineral fertilizers are an effective strategy for targeting improved common bean yield under indigenous soil taxonomy of Buganda catena soils. Key words: Phaseolus vulgaris L, integrated soil fertility management, smallholder farming, soil type.

A comparative study of mountain-meadow and mountain-forest soils was performed within the entire Dolgorukovskaya Yayla—a plateau on the northern macroslope of the Main Ridge of the Crimean Mountains—in the altitudinal range from 560 to 975 m a.s.l. Soil morphology, texture, acidity, exchangeable cations, nonsilicate iron content, parameters of the humus status, and optical characteristics of soils were studied. Forest soils on the entire slope are assigned to acid and dark burozems (Cambisols, Luvisols); they are characterized by similar morphological properties and profile patterns of clay, humus, and nonsilicate iron. Mountain-meadow, mountain-meadow chernozem-like, and residual-carbonate soils (Phaeozems) are formed under meadow vegetation in the upper part of the plateau, and soils transitional to piedmont chernozems (Chernozems) are located in its lower part. Humus reserves in the 0- to 50-cm-thick soil layer varied from 16.6 to 42.2 kg/m2 under meadows and from 10.7 to 18.8 kg/m2 under forests. Soils under forest and meadow vegetation were characterized by an increase in acidity and a decrease in base saturation with the increase in the altitude. Acidity was generally higher in forest soils, while the difference in this parameter between forest and meadow soils in the upper part of the plateau was minimal. In soils under meadows, the content of oxalate-extractable iron also increased with the altitude, and its mean content in the A horizon (226 ± 67 mg/100) was higher than that in forest soils (183 ± 41 mg/100 g). More intense color of soils under grass vegetation as compared to soils under forests is mainly explained by the differences in the rate of organic matter humification and optical density of humic acids, the total humus content being similar in both groups of soils.

Application of monoammonium phosphate has been demonstrated to re-immobilize glyphosate sorbed by soil under model laboratory experiment conditions. This effect was most pronounced in the gray forest soil (Haplic Phaeozem), where the concentration of herbicide in the presence of fertilizer was 3.6 times higher than in its absence. For soddy-podzolic soil (Albic Retisol) and leached Chernozem (Luvic Chernozem), this ratio was 1.5 and 2.8, respectively. Thus, the introduction of monoammonium phosphate into soils contaminated with glyphosate may result in an increase of the risk of herbicide migration into the neighboring environments. The estimated number of functional genes of bacteria responsible for glyphosate degradation by means of the C–P bond cleavage did not show statistically significant effect of the fertilizer on the number of copies of the phnJ gene, encoding the C–P lyase of α- and γ-proteobacteria. The release of glyphosate was not accompanied by any adverse effects on the length and biomass of wheat plants.

The postagrogenic dynamics of organic carbon (Corg), total nitrogen (Ntot), and density fractions of organic matter (OM) in the dark gray soil (Haplic Phaeozem, Belgorod oblast, Les na Vorskle (Forest on Vorskla) Reserve) and migrational–mycellary Chernozem (Haplic Chernozem, Kursk oblast, Streletskaya Steppe Reserve) were examined. The most significant postagrogenic changes in all the studied soil properties were observed in the top 0–5 cm layer. The contents of Corg and Ntot in this layer of the Phaeozem chronosequence increased by 1.2–1.3 times over 45 years after cessation of farming. The contents of Corg and Ntot in the top 0–5 cm layer of Chernozem chronosequence increased by 1.9–2.0 times over 60 years of the postagrogenic development. The accumulation of Corg took place in all density fractions. In both chronosequences, the free fraction of organic matter (density

The addition of maize residue nitrogen (N) to the soil strongly influences soil N accumulations, but the specific contributions of maize residue N to soil aggregates based on long-term fertilization remain largely unknown. This study involved a 360-day laboratory incubation experiment to determine the dynamics of N derived from maize straw in Mollisol soil aggregates applying different long-term fertilization treatments. In 2015, three soil samples from different fertilizers treatments were collected from the upper layer of soil (0–20 cm) of the field at a long-term Mollisol (Luvic Phaeozem) experimental site established in 1980 in Gongzhuling, Jilin Province, China. The fertilizer treatments included no fertilizer (CK); a combination of nitrogen, phosphorous and potassium fertilizers (NPK); and NPK combined with manure (MNPK). Three treatments of soils were incubated for 360 days at 25 °C, with or without 15N-labeled maize straw and destructively collected on days 45, 90, 135, 180 and 360. Soil samplings were separated into two aggregate fractions (macroaggregates, ≥ 0.25 mm; microaggregates, NPK > CK after 360 days of incubation. The results revealed that the combined application of chemical fertilizer and organic manure had higher capacity to retain maize straw–derived N, and more of it was retained in macroaggregates in the beginning. The addition of straw residue accelerated the formation of macroaggregates in the soils with lower C/N ratios.

Soil organic carbon (SOC) sequestration is influenced by incorporation of maize straw and application of fertilizers, in intensive agricultural regions. However, there is a limited understanding of the transformation and stabilization of the newly added carbon (C) in soils applied with different amounts of straw residue. The aim of this study was to quantify the relationship between straw C input and SOC sequestration across soil types. We applied 13C-labeled maize straw (at amounts of 0 g, 1 g, 3 g, 5 g, 10 g per 100 g dried soil), combined with an in-situ carborundum tube method, in fertilized and non-fertilized Phaeozem and Luvisol soils at experimental sites in Northeast China. Over a period of 360 days, we found that the added amounts of maize straw, and fertilization, affected the residual rates, distribution and stabilization of extraneous new C. Fertilized treatments resulted in lower residual rates of maize straw at the end of the experimental period compared with non-fertilized treatments. We observed that the increased SOC from maize straw amendment (1.08 g C kg−1, the average for all treatments) could not compensate for the loss of native SOC (2.49 g C kg−1 soil, the average for all treatments) with 1 × C maize straw input. However, 5 × C and 10 × C straw addition were enough to offset the native SOC loss. An increase in maize straw incorporation with non-fertilized treatments caused the largest increase in new SOC formation which was highest (84.5%) for 10 × C maize straw input at the end of 360 days incubation at the Luvisol site. With increasing C input, turnover rate was observed to increase from 0.06 (1 × C) to 5.07 year−1 (10 × C), and the C turnover in each level of maize straw addition decreased with incubation time. These results demonstrate that soil type, fertilizer application, and a threshold amount of maize straw input are needed to drive net SOC sequestration.

The aim of the study was to evaluate the changes in glomalin-related soil proteins (GRSP) content, microbial diversity and soil physical quality depending on the type of soil measures of soil improvement and changes in soil health. The study was based on a 100-year stationary field microplot experiment where the soil profiles were collected with preserving the natural soil horizons. The microplot experiment was carried out on eight different soil types: Brunic Arenosol (Dystric I), Rendzic Leptosol, Fluvic Cambisol, Haplic Cambisol (Eutric), Gleyic Phaeozem, Brunic Arenosol (Dystric II), Haplic Cambisol (Eutric II) and Haplic Cambisol (Dystric). These soils are the most common types of agricultural soils in Poland. Relatively significant correlations with the soil quality, physical parameters and the glomalin-related soil proteins have been found. The study determined the total GRSP (T-GRSP) and easily extractable GRSP (EE-GRSP) levels in soils as well as the soil physical quality index and soil&rsquo, s microbial biodiversity. The GRSP depended on the type of soil and correlated with S-Index and also was responsible for the unique chemical and physical properties of soils. Soils characterized by the highest T-GRSP content belonged to the group of very good and good soil physical quality characterized also by high biological activity, for which there were strong correlations with such parameters as dehydrogenase activity (DHA), microbial biomass content (MBC), microbial nitrogen content (MBN) and total bacteria number (B). The highest T-GRSP content and higher microbial diversity were found in Gleyic Phaeozem, Rendzic Leptosol and Fluvic Cambisol. The T-GRSP and EE-GRSP content were additionally correlated with the number of AMF spores. Very poor and poor soil physical quality according to S-Index characterized Brunic Arenosol (Dystric I) and Haplic Cambisol (Dystric). This research indicates that a specific edaphone of soil microorganisms and GRSP content may be of great importance when assessing a soil&rsquo, s quality and improvements in soil health. The abundance of glomalin-producing fungi significantly affects the quality of the soil. This effect is particularly important for agricultural soils are threatened by ongoing land degradation.

The trends of enzyme activities and litter chemistry after abandonment of arable soil and succession of natural vegetation were studied in a deciduous forest zone (Moscow region, Russia). The Luvic Phaeozem chronosequence included an arable field, 3 fields with increasing abandonment periods (7, 11, 35 years), and the soil under natural forest as a reference site (never used for cropland). The activities of four hydrolytic enzymes (β-glucosidase, cellobiohydrolase, β-galactosidase, chitinase) in the topsoil (0–5 cm) were compared with chemical functional groups of plant litter identified by 13C NMR spectra. The total enzyme activity increased 5-fold during 35 years of postagricultural restoration of arable soil. The share of C-cycle enzymes with “narrower” substrate specificity (cellobiohydrolase and chitinase) increased during 35 years from 19% to 42% of the total enzyme pool. We explain this gain by the increase in the diversity and recalcitrance of organic compounds in the plant litter from cropland to natural forest. Aromaticity index of plant litter built up remarkably: from 0.11 in the young abandoned land to 0.14–0.15 in the 35-year abandoned land and the reference site. The share of enzymes with a “narrower” substrate specificity correlated closely with the portions of aryl C, O-aryl C, and carbonyl C functional groups in plant litter. Accordingly, the succession of natural vegetation on abandoned cropland leads to strong diversification of the plant litter composition and a corresponding production of soil enzymes with “narrower” substrate specificity.

The aim of the study. The aim of the study was to describe the fertility of Greyzemic Chernozems, Нaplic Chernozem and Greyzemic Phaeozems located on erosion-prone slopes; to evaluate the yield and grain quality of spring soft wheat. The location and time of the study. Research was conducted on soils of the three experimental plots. The study area was located in the southeastern part of West Siberia within the boundaries of the Bugotak Hills (called Cis-Salair region) on the right bank side of the Ob River in the Novosibirsk region in the south of West Siberia. Plot 1 was located in the Iskitim district of the Novosibirsk region on the slope of southern exposure with 0- 6o gradient and occupied by Greyzemic Chernozems with different degree of soil erosion. In the Toguchin district of the Novosibirsk region two plots were located. Plot 2 was located on the slope of southeastern exposure with 0- 6.5o gradient and occupied by Нaplic Chernozems and Greyzemic Phaeozems. Plot 3 was located on the slope of northwestern exposure with 0-4.5o gradient and occupied by the non-eroded, slightly and moderately eroded Greyzemic Phaeozems. Cereal crops were spring soft wheat of two cultivars: Novosibirskaya 29 (plot 1; 2010 and 2014) and Memory of Vavenkov (plots 2, 3; 2011). Metodology. Two replicate soil samples were collected from the soil profiles at the sites differing in soil erosion degree. Four wheat phytomass samples were taken by a special frame 50×50 cm. The main results. Content and stock of soil organic carbon and total nitrogen decreased due to the increased soil erosion of Greyzemic Chernozems, Нaplic Chernozems and Greyzemic Phaeozems (Luvic) with maximal values in the Greyzemic Phaeozem (Colluvic). The N-NO3 in soils was low; the content of easily available phosphorus varied from the moderate to the high level, whereas the content of exchangeable potassium varied from low to increased level. Under extensive land use and restricted water reserves the wheat yield varied from 0.5 to 5 t/ha on the non-eroded Greyzemic Chernozems located on the south-exposed slope (plot 1). On the eroded soils the yield was found to be the same as on the non-eroded soil or even had a tendency to increase on slightly and moderately eroded soils. The maximal wheat yield (3.3 t/ha) was obtained on the Greyzemic Phaeozem (Colluvic). Between the non-eroded Нaplic Chernozems, eroded and stratified soils of the southeastern exposure (plot 2) there were no statistically significant differences in the yield, which varied from 3.2 to 4.1 t/ha. On the non-eroded Greyzemic Phaeozems (Luvic) of the northwestern exposure of the slope (plot 3) the yield was 4.3 t/ha, while on the slightly and moderately eroded soils it decreased to 1.1 t/ha. The mass of 1000 grains of wheat indicated the group with high mass (>30 g). The nitrogen content in grain and straw was low; potassium content was below the moderate level, while the content of phosphorus in grain was found to be optimal, and in straw it varied from the high to the low level. The content of raw protein was low (5-8%. The grain accounted for 35-48% of the total aboveground wheat phytomass. Conclusion. Nutrient regime of eroded soils is determined by soil profile transformation due soil erosion process and its intensity, as well as due to anthropogenic factors. Potential and actual fertility of Нaplic Chernozems and Greyzemic Phaeozems are higher than that of Greyzemic Chernozems. The productivity of soft spring wheat depends on the quantity of atmospheric precipitation, type and degree of soil erosion and slope exposure.

Soil aggregates play a crucial role in the sequestration of soil organic carbon (SOC). Returning crop residues to soil is known to strongly influence soil C stocks, but the specific contribution of crop residues to soil aggregates influenced by long-term fertilization remains largely unknown. This study investigated the effects of long-term fertilization on the distribution of 13C-labeled maize straw residue in different aggregate size fractions and their retention in soils over a 1-year incubation. The dynamic variation and the distribution of maize straw-derived 13C in soil aggregates were monitored using a 13C stable isotope mass-balance approach. The following three fertilization treatments were selected: (1) without fertilization (CK), (2) mineral fertilizer (NPK), and (3) cow manure with mineral fertilizer (NPKM). Soil samples were collected from the surface layer (0–20 cm) of a long-term field experiment of Mollisols (Luvic Phaeozem) in 2015 at Gongzhuling, Jilin Province, China, which was established in 1980. Soils were incubated for 360 days at 25 °C, with or without 13C-labeled maize straw and destructively collected on the days of 45, 90, 135, 180, and 360. Soil aggregates were separated into two fractions (macroaggregates, > 250 μm; microaggregate, NPK > CK for all soil aggregates after the 360-day incubation. Our results illustrated that long-term application of manure with mineral fertilizer helps to stabilize or increase the retention of exogenous C in the soil aggregates.

Nitrification inhibitors, a promising tool for reducing nitrous oxide (N2O) losses and promoting nitrogen use efficiency by slowing nitrification, have gained extensive attention worldwide. However, there have been few attempts to explore the broad responses of multiple reactive gaseous nitrogen emissions of N2O, nitric oxide (NO) and ammonia (NH3) and vegetable yield to nitrification inhibitor applications across intensive vegetable soils in China. A greenhouse pot experiment with five consecutive vegetable crops was performed to assess the efficacies of two nitrification inhibitors, namely, nitrapyrin and dicyandiamide on reactive gaseous nitrogen emissions, vegetable yield and reactive gaseous nitrogen intensity in four typical vegetable soils representing the intensive vegetable cropping systems across mainland China: an Acrisol from Hunan Province, an Anthrosol from Shanxi Province, a Cambisol from Shandong Province and a Phaeozem from Heilongjiang Province. The results showed soil type had significant influences on reactive gaseous nitrogen intensity, with reactive gaseous nitrogen emissions and yield mainly driven by soil factors: pH, nitrate, C:N ratio, cation exchange capacity and microbial biomass carbon. The highest reactive gaseous nitrogen emissions and reactive gaseous nitrogen intensity were in Acrisol while the highest vegetable yield occurred in Phaeozem. Nitrification inhibitor applications decreased N2O and NO emissions by 1.8-61.0% and 0.8-79.5%, respectively, but promoted NH3 volatilization by 3.2-44.6% across all soils. Furthermore, significant positive correlations were observed between inhibited N2O+NO and stimulated NH3 emissions with nitrification inhibitor additions across all soils, indicating that reduced nitrification posed the threat of NH3 losses. Additionally, reactive gaseous nitrogen intensity was significantly reduced in the Anthrosol and Cambisol due to the reduced reactive gaseous nitrogen emissions and increased yield, respectively. Our findings highlight the benefits of nitrification inhibitors for integrating environment and agronomy in intensive vegetable ecosystems in China.

The postagrogenic dynamics of acidity and some parameters of humus status have been studied in relation to the restoration of zonal vegetation in southern taiga (podzolic and soddy-podzolic soils (Retisols)), coniferous-broadleaved (subtaiga) forest (gray forest soil (Luvic Phaeozem)), and forest-steppe (gray forest soil (Haplic Phaeozem)) subzones. The most significant transformation of the studied properties of soils under changing vegetation has been revealed for poor sandy soils of southern taiga. The degree of changes in the content and stocks of organic carbon, the enrichment of humus in nitrogen, and acidity in the 0- to 20-cm soil layer during the postagrogenic evolution decreases from north to south. The adequate reflection of soil physicochemical properties in changes of plant cover is determined by the climatic zone and the land use pattern. A correlation between the changes in the soil acidity and the portion of acidophilic species in the plant cover is revealed for the southern taiga subzone. A positive relationship is found between the content of organic carbon and the share of species preferring humus-rich soils in the forest-steppe zone.

Biochar amendment to soil has been proposed as a strategy for sequestering carbon, mitigating climate change and enhancing crop productivity. However, few studies have compared the general effect of different feedstock-derived biochars on the various gaseous reactive nitrogen emissions (GNrEs) of N2O, NO and NH3 simultaneously across the typical vegetable soils in China. A greenhouse pot experiment with five consecutive vegetable crops was conducted to investigate the effects of two contrasting biochars, namely wheat straw biochar (Bw) and swine manure biochar (Bm) on GNrEs, vegetable yield and gaseous reactive nitrogen intensity (GNrI) in four typical soils which are representative of the intensive vegetable cropping systems across mainland China: an Acrisol from Hunan Province, an Anthrosol from Shanxi Province, a Cambisol from Shandong Province and a Phaeozem from Heilongjiang Province. Results showed that remarkable GNrE mitigation induced by biochar occurred in Anthrosol and Phaeozem, whereas enhancement of yield occurred in Cambisol and Phaeozem. Additionally, both biochars decreased GNrI through reducing N2O and NO emissions by 36.4–59.1 and 37.0–49.5 % for Bw (except for Cambisol), respectively, and by improving yield by 13.5–30.5 % for Bm (except for Acrisol and Anthrosol). Biochar amendments generally stimulated the NH3 emissions with greater enhancement from Bm than Bw. We can infer that the biochar's effects on the GNrEs and vegetable yield strongly depend on the attributes of the soil and biochar. Therefore, in order to achieve the maximum benefits under intensive greenhouse vegetable agriculture, both soil type and biochar characteristics should be seriously considered before conducting large-scale biochar applications.

Organic manure application is a feasible approach to alleviate the deterioration of soil erosion on soil organic carbon (SOC). However, to what extent manure application can restore carbon contents in SOC fractions in the eroded Phaeozems remains unknown. A 5-year field experiment was conducted in an artificially eroded Phaeozem with up to 30 cm of topsoil being removed. Chemical fertiliser, or chemical fertiliser plus cattle manure was applied. The contents of SOC were 23.6, 21.6 and 15.1 g C kg−1 soil for non-soil removal control, 10 and 30 cm of topsoil removal, respectively. Compared with the chemical fertiliser-only treatment, the chemical fertiliser plus manure application markedly increased SOC contents by 30–45% and C sequestration rates by 7.1–9.0-fold, especially in the fraction of 53–250 μm particulate organic carbon. However, with manure applied, SOC content in the fraction of mineral associated organic carbon in the 30 cm topsoil-removed soil was 2.9 g kg−1, 14.7% less than control (3...

The aim of the study was to review indicators and propose grades of soil potassium availability to crops.. The need of assessing soil potassium status on the basis of combined use of several diagnostic indicators, characterizing soil potassium pool, both quantitative and qualitative, is substantiated; at the same time, it is indispensable to take into account some properties of a specific soil, such as particle size distribution and cation exchange capacity. The diagnostics of soil potassium status in the long-term field experiments conducted in the forest-steppe zone of West Siberia was carried out. Results and conclusions. It was found that over 40 years of the experiment on the meadow chernozemic soil (Gleyic Chernozem) with initially very high potassium supply the content of exchangeable potassium decreased from 60 to 30 mg/100 g soil; at the same time, the level of easily exchangeable potassium decreased from 4.0 to 1.1-1.2 mg/100 g soil, indicating a significant deterioration in soil desorption capacity in relation to potassium. In the gray forest soil (Phaeozem) that was initially supplied with potassium, the content of its exchangeable and easily exchangeable forms decreased in 5–7 years of experiments to a critical minimum level, i.e. from 12 and 2 to 6–7 and 0.4–0, 5 mg/100 g soil, respectively. During the subsequent years (25 years) this content remained unchanged. It is concluded that systematic application of potassium together combined with nitrogen and phosphorus background fertilization ensured optimization of potassium status of soils.

Post-agricultural natural restoration is a worldwide strategy for eco-environmental sustainability. However, it is unclear how it affects soil organic carbon (SOC) pools and composition among soil types across climate gradient. Here, we investigated 23-year post-agricultural restorations of SOC in three soils: Luvic Phaeozem, Calcaric Cambisol and Ferralic Cambisol typical for mid-temperate, warm-temperate and subtropical zones, respectively. Six SOC fractions with different protection mechanisms (non-protected, physically, chemically, biochemically, physico-chemically and physico-biochemically) were separated. Compared with pre-restoration in 1990, post-agricultural restoration rebuilt SOC similarly (+68–+91%) among the three soils despite of different SOC background. Compared with continuous cultivation, post-agricultural restoration increased total SOC pools in all the three soils (+33–+60%) mainly because of the increments of non-protected pool (coarse particulate organic C, cPOC). However, the pure physically, chemically, and biochemically protected SOC fractions were less sensitive to post-agricultural restoration. The physico-biochemically protected SOC was hampered by restoration in the two temperate soils but remained stable in the subtropical soil, suggesting a divergent self-restoring trend. Positive correlations of the total SOC and most fractions with wetness (precipitation/temperature ratio) demonstrated the climate dependency of SOC. In conclusion, post-agricultural natural restoration builds up SOC pool mainly due to the cPOC increment and shifts SOC composition towards more easily available C in three soils across the climatic gradient.

Catch crop cultivation for green manure is considered to be a sustainable agricultural strategy whose main goal is to mitigate the negative effects of inappropriate plant sequent by increasing the soil biological activity, improving the nutrient content and reducing their loss from soil. Additionally, correct catch crop management is expected to improve the yield of consequent crops as well as their quality parameters. The effects of field pea when used as a catch crop, either incorporated in autumn or mulched and incorporated in spring vs. a control—without a catch crop on the soil chemical properties (total N, organic C, available forms of K and P) and the composition of spring barley grain and straw (total N, P, K, Ca) were studied for three years (2009 to 2011) in two-field, one-factor experiments, which were conducted on two different soil types (Luvisol and Phaeozem). The catch crop had no effect regarding the soil pH, soil organic C or total N content. In turn, applying a catch crop significantly affected the concentration of the available K (in both soils) and available P content (Phaeozem). The effect of a catch crop on the nutrients in the grain and straw of spring barley was associated with the soil type. In Luvisol, a catch crop, independent of its management, increased the total N and P in the grain and straw of spring barley. In Phaeozem, a catch crop that was incorporated in the autumn significantly increased the K content in grain.

In the presented study we estimated the effect of long-term application of (I) various systems of soil cultivation: (i) conventional tillage, (ii) reduced tillage and (iii) no-tillage, (II) wheat monoculture – spring and winter forms, and (III) crop rotation, on the basic physical properties of Rendzic Phaeozem. In the experiment soil physical properties were studied, such as particle density, bulk density, total porosity, air capacity (at -15.5 kPa), water content at sampling, field water capacity (at -15.5 kPa), available water content and the ratio of field water capacity and total porosity was calculated. The hypothesis that long-term wheat monoculture and/or reduced tillage have a negative effect on the soil physical condition has been verified. It should be emphasised that the long-term application of reduced tillage systems and wheat monoculture did not cause significant differences in the analysed parameters. The lowest compaction and the best conditions for gas exchange were noted in the soil on which conventional tillage was applied under spring wheat monoculture. The results of field water capacity and available water content showed that long-term application of reduced systems of soil tillage had a positive effect on the water properties of soil. Soil under the conventional tillage ensured significantly the smallest amount of water for the plants. It has been shown that long-term application of reduced tillage, as well as the form of wheat (spring or winter wheat), have a stronger impact on changes in the soil-water-air relations than long-term use of monoculture. We found out that both the use of reduced tillage and the abandonment of crop rotation in favour of monoculture can be put into safely use in agricultural practice. We believe that the application of such systems is especially valuable in emergency situations.

Knowledge of sulphur (S) speciation in soil following applications of chemical and organic fertilizers is important for understanding the availability and fate of S in agricultural ecosystems. Sulphur speciation of the soil in three fields, which are part of the National Long-term Monitoring Network of Soil Fertility and Fertilizer Effects of China, was investigated with a combination of a wet-chemical fractionation scheme and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. Treatments of the soil included no fertilizers (control), regular applications of nitrogen, phosphorus and potassium fertilizers (NPK), or of NPK plus organic manures (MNPK) since 1990. Soil samples were taken from the topsoil (0–20 cm) and subsoil (20–40 cm) horizons in 2011. Chemical fractionation showed that available sulphate was the predominant inorganic S species in the Eutric Cambisol, whereas HCl-extractable sulphate was the main inorganic S species in the Haplic Phaeozem and Calcaric Cambisol. Organic S accounted for up to 77% of total S in all soil samples. Results from the fractionation (inorganic S plus ester-S) and XANES analysis (oxidized S) were correlated (r = 0.585, P < 0.01), which confirmed the presence of HCl-extractable sulphate and the speciation of residual S in soil. Long-term application of organic manures facilitated significantly the accumulation of intermediate and reduced S species and increased total and organic S in the soil (P < 0.01). In contrast, the application of chemical fertilizers (NPK) had little effect on the distribution of organic S species compared with the control. Atmospheric deposition was identified as an important source of S. The combination of chemical fractionation and XANES spectroscopy provided complementary information on the availability and speciation of S in soil. Highlights Availability and species of S are characterized with chemical fractionation and XANES spectroscopy. Insoluble sulphate is identified as an important form of S in the soil regardless of soil pH. Organic manure facilitates the accumulation of organic S in long-term fertilized soil. Atmospheric deposition contributes importantly to the input and cycling of S in soil.

The sunflower is a newly planted crop in the Czech Republic, which represents the northern edge of the species’ range, and there is a lack of information about the effect of nutrient application on yield components. To fill this gap, we performed a fertilizer experiment on Greyic Phaeozem over the years 2008–2012 to evaluate the effects of N, B, Zn and Mo application on achenes yield. We compared the control (C) without any N fertilizer, N treatments (N 60, N 90, N120 kg N ha−1) and N treatments accompanied with micronutrients (N 90+B – 0.3 kg B ha−1, N 90+Zn – 0.35 kg Zn ha−1, N 90+Mo – 0.125 kg Mo ha−1). The mean achenes yield over all years ranged from 3.9 in C to 4.34 t ha−1 in N 60. Achenes yield over all treatments ranged from 3.04 in 2008 to 4.91 t ha−1 in 2010. We concluded that sunflower can be produced with application rate up to 60 kg N ha−1 on highly productive soils in the Czech Republic and for similar other soils in the region. The increase in N application above 60 kg N ha−1 can decrease achenes yield. Application of B and Zn achieved slightly higher, while the addition of Mo slightly lower achenes yields when compared to the treatment with the same level of N and without micronutrients addition. We concluded that the application of micronutrients at the sites with sufficient content of those micronutrients in soil has almost no effect on achenes and biomass yield. Achenes and biomass yield was primarily affected by weather conditions in particular years, affecting plant growth, disease and predatory occurrence. Fertilizer treatments did not significantly affect the weight of achenes per head, weight of thousand achenes, the number of achenes per head, the number of heads per ha and number of achenes per ha during the experiment. The significant effect of the year was recorded, showing major effect of weather conditions on above mentioned parameters.

This experiment takes phaeozem paddy field as the object of study to research for the optimum water and fertilizer application scheme for mitigation of N2O emissions. The effects of nitrogen, phosphorus, potassium and irrigation rate on N2O emissions in growing season under controlled irrigation was analyzed by four-factor quadratic saturation D-optimum design scheme, using the method of static chamber-gas chromatographic techniques. The results showed that nitrogen had most significant effects for N2O emissions in growing season and the increase of nitrogen showed promotion effects for N2O emissions; the effects of phosphorus and potassium were not obvious; the increase of irrigation promoted N2O emissions at an earlier stage but inhibited it latter. In consideration of yield, an optimum management plan of water and fertilizer was suggested for N2O reduction by 0%~20%, that was 114.72 kg/hm 2 for nitrogen, 50.25 kg/hm 2 for potassium, 17.64 kg/hm 2 for phosphorus, 80% for relative soil water content at late tilling stage. Under this scheme, the yield was 79.23 g/pot, with an increase rate of about 19.6% (compared with the control group); the emission load was 0.095 g/m 2 in growing season, with an reduction rate of about 8% (compared with the

A long-term field experiment on a Haplic Phaeozem, established 1949 with four levels of potassium (K) supply (5, 69, 133, and 261 kg K ha−1), was analyzed for the interaction between K supply and yield loss of five crop species by water shortage. The crop species were cultivated simultaneously side-by-side in the following rotation: potato (Solanum tuberosum L.), silage maize (Zea mays L.), spring wheat (Triticum aestivum L.), beet (Beta vulgaris L.), and spring barley (Hordeum vulgare L.). The treatment with 133 kg K ha−1 supply had a nearly balanced K budget. In the treatments with lower supply, the soil delivered K from its mineral constituents. On the low-K plots (especially on those with only 5 kg K ha−1), crops suffered yield depressions of nearly all main harvest products (cereal grains, potato tubers, beet storage roots, silage maize) and by-products (straw, beet leaves) by up to 40.7% of dry matter. Only wheat grains were an exception. Potassium concentrations in the harvested plant parts decreased nearly in parallel to the reduction of their dry matter yields, with the exception of cereal grains, which kept stable concentrations even in the treatment with only 5 kg K ha−1. A comparison of four year-pairs with differing levels of precipitation in yield-relevant periods showed an average water shortage-induced depression of dry matter yields by 19.7% in the main harvest products. The severity of this yield depression was not mitigated by elevated K supply, with the exception of beet leaves, where the dry matter production was stabilized by high K supply. In this crop, the reduction of storage-root yield was associated with a decrease in harvest index and was therefore obviously caused by an inhibition of assimilate translocation from the leaves into these organs, in contrast to cereals, where water shortage primarily affected dry matter production in vegetative organs. It is concluded that the physiological causes of yield reduction by drought stress and the possibility of its amelioration by K supply differ between plant species and organs.

Wheat is a crop of global importance that supplies carbohydrates to more than half of the worlds’ population. We examined whether climate change-induced rainfall patterns, which are expected to produce less frequent but heavier rain events, will alter the productivity of wheat and agroecosystem functioning on three different soil types. Therefore, in a full-factorial experiment, Triticum aestivum L. was cultivated in 3-m2 lysimeter plots, each of which contained one of the following soil types: sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem. Predicted rainfall patterns based on the calculations of a regionalised climate change model were compared with the current long-term rainfall patterns, and each treatment combination was replicated three times. Future rainfall patterns significantly reduced wheat yield, leaf area index, and plant height at the earlier growth stages; it equally decreased the arbuscular mycorrhizal fungi colonisation of roots and increased the stable carbon isotope signature (δ13C) of wheat leaves. Sandy soils with inherently lower mineralization potential negatively affected wheat growth, harvest index, and yield but stimulated early season root production. The interaction between rainfall and soil type was significant for the harvest index and early wheat development. Our results suggest that changes in rainfall intensity and frequency can significantly affect the functioning of wheat agroecosystems. Wheat production under future rainfall conditions will likely become more challenging as further concurrent climate change factors become prevalent.

Perennialization and reducing tillage have increased soil organic matter (SOM) in both aggregate and particulate organic matter (POM) in short-term and small scale experiments, but there is a need for investigations into the long-term effects of agroecosystems on these dynamic pools of SOM. The objectives of this study were to investigate how management varying in crop rotation, tillage intensity and organic management from 1990 to 2013 has affected POM and aggregate C and N, and assess the relationship between these SOM fractions and biomass C inputs. We hypothesized that tillage, low biomass inputs, and annual crops in rotation would be associated with decreased POM and aggregate C and N. Soil from six systems from the Wisconsin Integrated Cropping Systems Trial (WICST) on a Phaeozem, or Mollisol, was sampled in 2013: Continuous Maize ( Zea mays L.), Maize–Soybean [ Glycine max (L.) Merr.], Organic Grain (including maize, soybean, and wheat [ Triticum aestivum L.] sequentially seeded with oats [ Avena sativa L.] and berseem clover [ Trifolium alexandrinum L.]), Conventional Forage (three years alfalfa [ Medicago sativa L.] followed by maize), Organic Forage (two years’ alfalfa with oats nurse crop followed by maize), and Pasture (rotationally grazed, seeded to a mixture of red clover [ Trifolium pratense L.], timothy [ Phleum pretense L.], smooth bromegrass [ Bromu sinermis L.] and orchardgrass [ Dactylis glomerata L.]). Among all systems at 0–25 cm depth, we found significantly greater concentrations of POM-C in the Pasture (4.4 g C kg −1 soil) and POM-N in Pasture (0.30 g N kg −1 soil) and Organic Forage (0.25 g N kg −1 soil). The Organic Grain system had lower concentrations of macroaggregates and lower stocks of C and N within macroaggregates. Across all systems, belowground biomass C input was significantly positively correlated with POM-C, POM-N, and aggregate C and N. The data supported our hypothesis in part, as results indicate that frequent cultivation in the form of tine weeding and rotary hoeing for weed control in Organic Grain rotation is likely disrupting formation of aggregates and storage of C and N therein. However, in systems that were chisel plowed every one to three years, high biomass C inputs maintain POM-C and POM-N and soil aggregation equivalent to the fully perennial system.

Carbon and nitrogen compounds and the emission of CO2, CH4, and N2O were studied in the ancient buried and modern background soils developed from different parent materials in the Arkaim Reserve of Chelyabinsk oblast. The studies were performed after an 18-year-long period of absence of anthropogenic loads on the local ecosystems. Element contents in the humus horizons of the chernozems of the former plowland and pastures and of the forest soil reach 28–45.6 g/kg for Corg, 2.5–4.5 g/kg for Ntot, 140–423 mg/kg for labile carbon (Cl), 32–73 mg/kg for labile nitrogen (Nl), 350–952 mg/kg for carbon of microbial biomass (Cmic), and 38–85 mg/kg for nitrogen of microbial biomass (Nmic). The contents of different forms of C and N depend on the soil type and texture and on the type of land use, including that before reservation of the territory. The emission of greenhouse gases was examined in this area for the first time. The production of CO2 by the soil buried about 4000 years ago is an order of magnitude lower than that by the modern soil. The emission and sink of N2O are small in both modern and ancient soils. The behavior of methane is clearly different in the automorphic and hydromorphic soils: the former serve as methane sinks, whereas the latter act as methane sources. The rate of the CO2 emission from the soils is controlled by many factors, including the soil type, texture, degree of hydromorphism, composition of parent materials, and type of land use.

Given the growing interest in ecological intensification directed towards sustainable crop production, a study was conducted to assess the biological and production response of pea intercropped with spring wheat or linseed under various growing conditions. The experiment was conducted in 2009–2011 on a Haplic Phaeozem soil in the western part of Poland. Intercropping of pea significantly reduced the green area index and the normalized difference vegetation index values, but growing pea with linseed caused a significant increase in the number of nodes with pods, pods per stem, and seeds per stem. Intercropping with wheat increased the seed number per pod. Seed inoculation with Nitragina significantly increased the number of pea pods and seeds per stem. Wheat intercropped with pea, with inoculation and foliar fertilization, attained significantly lower straw weight and spike length. Intercropping of linseed significantly reduced the features of the yield structure. Bacterial inoculation increased the production potential of pea at the expense of the supporting plants.

The aim of this study was to analyze the changes of soil microbial communities stimulated by climate, soil type and vegetation type using a functional gene array. The dataset GSE51592 was obtained from Gene Expression Omnibus, including 54 soil samples. Genetic diversity variation of samples under different sites, soil and vegetation types was examined by calculating the percentage of specific gene number in each sample. Furthermore, gene functional categories and microorganism species in samples under different environmental factors were respectively divided. Gene number in samples with cropping was higher than in samples without cropping. When site, soil type and vegetation type were as the sole variable, respectively, the percentage of specific genes in samples from Yingtan, in phaeozem samples and in samples with cropping was higher. Furthermore, the percentage of gene number in organic remediation for phaeozem and cambisol samples was significant at p

The Argentine Pampa is one of the most productive agricultural regions in the world, but sole crop management practices have led to soil degradation and losses of soil organic matter. The objective of this study was to evaluate soil organic carbon (SOC) and nitrogen (N) dynamics in 2007 and in 2012 in two intercrop systems [1:2 intercrop (one row of maize (Zea mays L.) and two rows of soybeans (Glycine max L. Merr.)) and 2:3 intercrop (two rows of maize and three rows of soybean)], and in a maize and soybean sole crop. Results showed that C and N input from crop residues was significantly greater (P < 0.05) in the maize sole crop, followed by the intercrops and the soybean sole crop. The land equivalent ratio (LER), based on crop biomass, was significantly greater (P < 0.05) in the 2:3 intercrop. Soil physical and chemical characteristics (bulk density, pH, SOC and N, C/N ratio) were not significantly (P < 0.05) different among treatments and were significantly greater in 2012, except for pH, at all depths. Gross SOC turnover time was significantly longer (P < 0.05) in 2012 compared to 2007 for all treatments and depths, except in the maize sole crop. Soil microbial biomass (SMB) C and N were significantly greater (P < 0.05) in the 2:3 intercrop in both years. To a 40 cm depth, SMB-C turnover time (SMB-CT) was significantly greater (P < 0.05) in the soybean sole crop followed by the intercrops and the maize sole crop in 2007, whereas in 2012, SMB-CT was significantly greater (P < 0.05) in the intercrops followed by the soybean and the maize sole crops. The soil light fraction N (LF-N) was significantly greater (P < 0.05) in the maize sole crop in both years. There was no significant difference (P < 0.05) for LF-C. Our results demonstrated that cereal–legume intercropping is a more sustainable agroecosystem land management practice in the Argentine Pampa, with respect to soil C and N transformations, compared to sole cropping. Fil: Oelbermann, Maren. University Of Waterloo; Canadá Fil: Regehr, Alison. University Of Waterloo; Canadá Fil: Echarte, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina

Root growth is affected by soil features that could change after erosion. The goal of this study was to understand how root growth responded to water stress resulting from erosion. For this purpose a pot experiment was conducted combining three eroded soils (lightly, moderately, severely) and four soil water levels (relative to field capacity of 100%, 80%, 60%, 40%) using nondisturbed Luvic Phaeozem soil from field by electric drill. The results showed that the response of soybean root growth to soil water was different for the three eroded soils and varied with growth stages of the plant. Under an optimal water supply, roots grew best in moderately eroded soils. Response of soybean root growth to water stress degree was similar under deficit water situation for three eroded soils, and under excess water stress situation, the root growth of lightly eroded soils was restricted more seriously than that of moderately and severely eroded soils during the initial branching stage. Root growth was restricted onl...

Snowmelt erosion is one of the reasons for the decreasing soil fertility in the most valuable agricultural lands in the south of West Siberia. The aim of this study was to examine the influence of long term soil use and degree of soil erosion on the main fertility indicators of Greyzemic Phaeozem (30-year fallow, non-eroded, slightly eroded, moderately eroded and strongly eroded). Soils were analysed for organic carbon (SOC), pHw, cation-exchange capacity and total and available forms of nitrogen, phosphorus and potassium. Plants were analysed for sheaf and grain yield and NPK content of wheat. A decrease in the content of the total forms of carbon and nitrogen and an increase in the C/N ratio were observed with an increase in the degree of soil erosion. SOC losses in the ploughed layer of slightly, moderately and strongly eroded soils were 6.6, 13 and 27%, respectively, while the nitrogen losses were 5, 33, and 71%. The widest (37) C/N ratio was found in strongly eroded soil. The content of total phosphorus in the ploughed layer of slightly, moderately and strongly eroded soils decreased by 3.8, 23 and 15.4%, respectively, in comparison with non-eroded soil. Available forms of phosphorus and potassium increased with an increase in the degree of soil erosion, with the highest values found in moderately eroded soil. Exchangeable K/available K ratio, the overall mobility of potassium in the eroded soils also increased. The highest plant productivity was found on moderately eroded soil. A deterioration of the nitrogen regime led to a narrowing of the N/K ratio from 2.4 (grain) and 0.4 (straw) up to 1.9 (grain) and 0.3 (straw) for non-eroded and strongly eroded soils respectively. A critical decrease of soil fertility and plant productivity was found in strongly eroded soil.

Root competition for below-ground resources between edible plants may provide for long-term sustainability of agriculture systems. Intercropping can be more productive than a pure crop due to taking advantage of the morphological differences between species. In pure cropping, all biophysical interactions between plants occur through soil conditions. In intercropping, competition for water and nutrients is of major importance, but if the roots of one species occupy the zone just underneath the roots of the other crop, they can better use the resources of the root zone of the crop. The root system demonstrates a high degree of plasticity in its development in response to local heterogeneity of the soil profile and plant density. This study aimed at determining: (i) the morphological characteristics of the root systems of linseed, pea and vetch depending on the method of sowing; (ii) the root distribution in various soil types and at different soil profile depths (0–15 cm, 15–30 cm). Two three-year field experiments were conducted on two soil types in south Poland: soil A – Luvic Phaeozem (s1) and soil B – Eutric Cambisol (s2). These results show that linseed was more aggressive toward both legumes in mixture, but it produced lower yield compared to pure cropping. The environmental stress of plants in mixtures increased the relative weight of roots, which resulted in decreasing the root-shoot ratio (RSR).

The Phaeozem region is an important grain production base in China and soil fertility has declined under long-term cultivation. Studying soil organic carbon (SOC) change in the upland phaeozem of Northeast China under different tillage modes has great theoretical and practical significance for reducing greenhouse gases emissions, increasing soil carbon stocks, and ensuring food security. This study applied the DAYCENT model to simulate six long-term experimental sites in the phaeozem region, and through calibration and validation analysis, it concluded that the DAYCENT model could effectively simulate the dynamic change of SOC in the upland phaeozems; hence, the relevant parameters of each site were determined. Under future climate scenarios (Representative Concentration Pathway 4.5, RCP 4.5), SOC change in agricultural soils (0–20 cm topsoil) of four different management scenarios (fertilizer application, manure amendment, straw return, no-tillage) was simulated. The overall simulated trend was no-tillage > straw return > manure amendment > fertilizer application. Fertilizer had no evident effect on increasing SOC, but the effect would be better if combined with manure; both straw return and no-tillage had the general effect of improving SOC and the simulated values rose rapidly with a large increasing rate within a short period; however, the increasing rate became gentle after 2050, reached a relatively stable level after 2080, then gradually reached carbon saturation. Untill 2100, the SOC content of each site reached a relatively higher level by adopting the no-tillage treatment, where the SOC contents of Harbin, Hailun, Nehe, Dehui, Gongzhuling and Lishu were 2.36 g/100 g, 2.81 g/100 g, 2.22 g/100 g, 2.38 g/100 g, 1.97 g/100 g and 2.01 g/100 g, respectively. The SOC contents increased by 52.47% when compared with the initial value, and the simulated average annual increase of SOC for 84 years was 0.0082 g/100 g.

The effects of 20 years of potassium (K) fertilization (in two treatments: 113 and 225 kg K2O ha−1) on grain and stover yields, plant K concentrations, aboveground K uptake, K use efficiencies, soil K pools, and the K balance were examined in a Haplic Phaeozem soil under a rain-fed mono-cropped spring maize (Zea mays L.) system in the province of Jilin, northeast China. The indigenous K supply (zero K application) maintained an average grain yield of 7.0 t ha−1 per year, but the year-to-year variation was large. Application of K significantly (P

How is grain yield and quality affected by fertilizer regime, soil type, and year is not yet well known. In 2011–2013 we analyzed yield and baking quality of grain on loamy degraded Chernozem (ICRE, 225 m a.s.l.), Greyic Phaeozem (CCRE, 263 m a.s.l.), and sandy loamy Cambisol (LCRE, 620 m a.s.l.) under the control (C), farmyard manure (FYM), and farmyard manure together with mineral NPK application (FYM + NPK) treatments.In 2011, the mean grain yields were 5.86, 6.82, and 10.6 t ha−1 in C, FYM, and FYM + NPK treatments, respectively; in 2012, the grain yields were only 3.92, 4.56, and 5.58 t ha−1, respectively, due to an extremely dry season; and in 2013, the grain yields were 5.74, 6.15, and 8.21 t ha−1, respectively, as the precipitation increased. In 2011, grain yields were the highest in the ICRE and the lowest in the LCRE, but in 2012, the highest yields were recorded in the CCRE and the lowest in ICRE. Kernel weight, crude protein content, bulk density of caryopses, and values of Zeleny sedimentatio...

Calcium chloride–extractable (1:10 soil/solution ratio, w/v) nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), organic nitrogen (EON), and Ntotal fractions were measured in two long-term experiments. Both experiments are located in the Great Hungarian Plain. The first experiment was established on a Luvic Phaeozem soil and the second experiment was on a Calcic Chernozem soil. Researchers investigated the effects of long-term fertilization and irrigation on the amounts of nitrogen (N) fractions. Nitrogen rates caused significant increase in NO3-N and Ntotal fractions. These fractions were in close correlation (r = 0.87; r = 0.88) with nitrogen balance. The nitrate content of the 200-cm-deep soil layer of soils under different nitrogen- and water-supply conditions were also studied. As an effect of N overfertilization, the maximum nitrate accumulation on nonirrigated plots occurred in the 200-cm depth, whereas on irrigated plots a nitrate accumulation layer could not be observed in the 200-cm-deep soil l...

Climate change scenarios for central Europe predict fewer but heavier rains during the vegetation period without substantial changes in the total amount of annual rainfall. To investigate the impact of rainfall patterns derived from regionalised IPCC scenarios on agroecosystems in Austria, we conducted an experiment using 3 m2 lysimeters where prognosticated (progn.) rainfall patterns were compared with long-term current rainfall patterns on three agriculturally important soil types (sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem). Lysimeters were cultivated with field peas (Pisum sativum) according to good farming practice. Prognosticated rainfall patterns decreased crop cover, net primary production (NPP) and crop yields, but increased root production and tended to decrease mycorrhization. Soil types affected the NPP, crop density and yields, weed biomass and composition, as well as the root production with lowest values commonly found in sandy soils, while other soil types showed almost similar effects. Significant interactions between rainfall patterns and soil types were observed for the harvest index (ratio crop yield versus straw), yield per crop plant, weed density and weed community composition. Abundance of the insect pest pea moth (Cydia nigricana) tended to be higher under progn. rainfall, but was unaffected by soil types. These results show that (a) future rainfall patterns will substantially affect various agroecosystem processes and crop production in the studied region, and (b) the influence of different soil types in altering ecosystem responses to climate change should be considered when attempting to scale-up experimental results derived at the plot level to the landscape level.

In absence of commercial fertilizers prehistoric agriculture relied heavily on nutrient supply from soil. This study was designed to reconstruct the phosphorus (P) status of prehistoric arable soils in order to highlight the possible importance of soil P limitation in Neolithic (after the Early Neolithic, i.e. around 4400 until 2200 BC) and Bronze Age (2200 until 700 BC) agriculture. For this purpose, we sampled buried archaeological topsoil relicts that have been preserved in prehistoric pit fillings outside ancient settlements in the loess areas in Central and Western Germany. Adjacent subsoils and recent topsoils served as references. Samples were characterized using sequential P extraction and selected samples were characterized using 31 P NMR spectroscopy. Prehistoric topsoil relicts in the investigated regions showed larger contents of organic matter and extractable P (sum of all sequentially extracted inorganic and organic P fractions) than the adjacent subsoils. Sampling the soils at higher depth resolution did not provide any evidence of P-leaching. The P content in the topsoil relicts amounted to approximately 86% of the P content of the modern, fertilized topsoils. Most of the extractable P (> 80%) comprised inorganic P. Organic P fractions were dominated by monoester-P. Intriguingly, plant available P contents (sum of resin-P i , NaHCO 3 -P i and NaOH-P i ) in the prehistoric topsoils and the recent topsoils were similar (23% and 20% of extractable P, respectively), suggesting that even plant available P was maintained in the prehistoric topsoil relicts. Also the contents of Ca-associated P were large, but reflected differences in pedogenesis among the sampling sites (Chernozem, Phaeozem and Luvisol). Hence, we have to conclude that there was no significant P limitation in the prehistoric farmland of the two loess areas, either because the soils had been fertilized or because the inherent P stocks were sufficient to sustain ancient farm yields. In any case our data do not support the hypothesis that prehistoric P limitations may have reduced crop yields.

In a long-term field trial (Halle, Germany, founded in 1949 by K. Schmalfus, soil type Haplic Phaeozem), the effects of different mineral and organic fertilization on dry matter yields, soil C and N contents and N balances were investigated. Over a period of 60 years, yields increased on average in all cultivated crops (winter and spring cereals, potatoes, sugar beets, silage maize), even without any fertilization. Nitrogen deficiency in unfertilized and PK treatments caused strong decreases in yield (up to 48%) in comparison with the N2PK standard treatment. The effect of omitting K or P supply was smaller (up to 18% and 7% yield reduction, respectively). The highest yields were obtained with high mineral N + PK application and (except winter wheat) with farmyard manure in combination with mineral fertilization. The N balances were negative in all treatments. However, if N immission from the air (40 kg ha−1 a−1) was included in the calculation, N balances were negative only in low N treatments. The soil ...

Heilongjiang Province is the main soybean-producing area in china. In this study, we analyzed the canopy structure, dynamic characteristics of light radiation and yield of Hefeng50 (the main variety of soybean in Heilongjiang Province) under six different cultivation patterns (ORP, TPCR, ORCP, BRHD, SRHD and FPHD). The results showed that SRHD and BRHD at different growth period (blossom period R1, podding R3 and grain filing period R5) produced an even distribution of the population leaf area, suitable mean foliage inclination angle (MFIA), low transparency coefficients for defuse penetration (TCDP) and transparency coefficients for radiation penetration (TCRP), high leaf area index (LAI), extinction light coefficient (K value), fraction of radiation intercepted (FRI) and light energy utilization rate. Grain number, dry matter weight per plant, and yield of SRHD and BRHD were significantly higher than those of other cultivation patterns. The yield of SRHD, BRHD, ORCP, FPHD and TPCR was increased by 136%, 112%, 79%, 50.1% and 14.7%, respectively, compared to that of ORP. These results suggest that SRHD and BRHD are the optimal cultivation pattern for the improvement of soybean yield in phaeozem region of northeastern China.

The main goal of the study was to determine the diversity of the potential nitrogen-fixing (PNF) bacteria inhabiting agricultural (A) soils versus wastelands serving as controls (C). The soils were classified into three groups based on the formation process: autogenic soils (Albic Luvisols, Brunic Arenosols, Haplic Phaeozem) formed on loess material, hydrogenic soils (Mollic Gleysols, Eutric Fluvisol, Eutric Histosol) formed under the effect of stagnant water and lithogenic soils (Rendzina Leptosols) formed on limestone. In order to determine the preferable conditions for PNF bacteria, the relationships between the soil chemical features and bacterial operational taxonomic units (OTUs) were tested. Additionally, the nitrogen content and fertilisation requirement of the lithogenic (LG), autogenic (AG) and hydrogenic (HG) soils were discussed. The composition of the bacterial communities was analysed with the next-generation sequencing (NGS) by the Ion Torrent™ technology. The sequences were clustered into OTU based on a 99 % similarity threshold. The arable soils tested were distinctly dominated by β-Proteobacteria representatives of PNF bacteria belonging to the genus Burkholderia. Bacteria from the α-Proteobacteria class and Devosia genus were subdominants. A free-living Cyanobacteria population dominated in A rather than in C soils. We have found that both soil agricultural management and soil formation processes are the most conducive factors for PNF bacteria, as a majority of these microorganisms inhabit the AG group of soils, whilst the LG soils with the lowest abundance of PNF bacteria revealed the need for additional mineral fertilisation. Our studies have also indicated that there are close relationships between soil classification with respect to soil formation processes and PNF bacteria preference for occupation of soil niches. Electronic supplementary material The online version of this article (doi:10.1007/s00248-016-0837-2) contains supplementary material, which is available to authorized users.

The decomposer soil community maintains the arable soil ecosystem for the nutrient turnover. Here, we studied the dynamics of the soil fungal populations in a typical Phaeozem luvico in Argentina and related it to the management practices. Soil samples (at 0–10 cm depth) were collected from a field cultivated with wheat, at different sampling times: at post-harvest, before sowing, and at tillering. The relative abundance of individuals in the population on Nash Snyder and Oxgall agar media was assessed as colony forming units (CFU). The fungal population was classified by numerical taxonomy at the different sampling times. The highest values of CFU g−1 of soil were found at post-harvest under reduced tillage and differed significantly from those at conventional tillage. The genera Trichoderma, Fusarium, Aspergillus, Penicillium, and Fusarium oxysporum were present in the largest number of samples and discriminated the fungal community between times. This discrimination could be related to alterations in the availability of carbon sources during stubble degradation at post-harvest and before sowing and were of lesser importance at tillering., Centro de Investigaciones en Fitopatología

The enhancement of soil organic carbon (SOC) is important for sustainable agriculture, while changes in SOC depend on the balance between carbon (C) input and export. To investigate how chemical fertilizers contribute to C input (e.g. plant-derived C) and export (e.g. original SOC decomposition) in soil, a wheat (a C3 plant) pot experiment was conducted using a Phaeozem that had previously been used to cultivate maize (a C4 plant). The natural 13C abundance method was used to quantify wheat-derived SOC (WSC) and microbial respiration using the original SOC (Rmicrobial) during the wheat growing season. The wheat grain, WSC, wheat-derived C (WDC: including WSC, root and stubble biomass C) and Rmicrobial-derived CO2 emission (SCE) in fertilized treatments increased by 4.8–31.1%, 48.9–122.4%, 21.3–62.2% and 6.0–51.8%, respectively, when compared to unfertilized treatments. The total SOC in the post-experimental soil increased by 0.14–0.97% when compared to pre-experimental soil because the WSC input was larger than the SCE export, and it would be increased further if wheat root and stubble biomass C were included. Therefore, application of chemical fertilizer not only directly increases crop yield, but also indirectly contributes to C sequestration by favoring crop growth and crop-derived C input in soil.

The study was concerned with the physical properties of a soil which was under natural fallow for ten years (1996–2005). The experimental sites were situated on a Rendzic Phaeozem originating from cretaceous bedrock. Two adjoining arable plots (0.2 ha area of each) cultivated during the period were compared with the fallowed plot (0.1 ha area). The soil under study has been in use as arable land for over 100 years. The crops most frequently cultivated included cereals, sugar beet and potato. The primary soil tillage system applied was the conventional plough tillage system. An oat and barley mix was grown on this plot immediately before the fallowing started. The paper provides a presentation of results concerning the following physical properties of the soil: bulk density (BD), total porosity (TP), field air capacity (content of macropores Φ > 20 μm — FAC), field air permeability (FAP), moisture at the sampling moment (SM), field water capacity (FC), available water retention (AWC), unavailable water retention — wilting point (UWC), and the calculated ratio FC/TP. After the ten-year period of lying fallow the physical condition of the studied soil improved markedly. What should be noted as particularly valuable was the fact that after six years of exclusion from cultivation there was an improvement of soil compaction (BD) and an increase in total porosity (TP), field air permeability (FAP), field water capacity (FC) and available water retention (AWC). The ten-year (1996–2005) mean value of BD of the fallow soil was 1.11 Mg m − 3 , that of the soil from Field I — 1.17 Mg m − 3 , and from Field II — 1.15 Mg m − 3 ; TP: fallow — 0.550 m 3 m − 3 , Field I — 0.531 m 3 m − 3 , Field II — 0.543 m 3 m − 3 ; FAP: fallow — 104.1 × 10 − 8 m 2 Pa − 1 s − 1 , Field I — 47.9 × 10 − 8 m 2 Pa − 1 s − 1 , Field II — 66.9 × 10 − 8 m 2 Pa − 1 s − 1 ; FC: fallow — 0.374 kg kg − 1 , Field I — 0.353 kg kg − 1 , Field II — 0.354 kg kg − 1 ; AWC: fallow — 0.221 kg kg − 1 , Field — 0.202 kg kg − 1 , Field II — 0.201 kg kg − 1 . In view of the acquired data it should assumed that long-term fallow of arable fields is one of the methods leading to the physical regeneration of soil. Favourable changes in the physical structure of soil can be achieved through the application of reduced or no-till tillage systems.

Soybean ( Glycine max L.)–maize ( Zea mays L.) rotation has been recommended as a good cropping practice for soil quality improvement and crop productivity enhancement. However, its impacts on carbon sequestration in soil are not well documented. The main objective of this study was to learn whether soybean–maize rotation can promote soil organic carbon (SOC) sequestration. Based on a long-term field experiment (started in 1990) in Northeast China, we investigated the differences in soil organic carbon (SOC) and soil aggregate composition between cropping patterns. This experiment included four treatments: continuous maize cropping (CMC), maize–soybean rotation (MSR), continuous soybean cropping (CSC) and farmland fallow (FALL) in a Haplic Phaeozem soil. All treatments showed a sustained trend toward increasing SOC storage since 1990. The contents of SOC in the topsoil and in the profile to the 1 m depth were in the following order of CMC > MSR > CSC ≥ FALL, suggesting a greater potential of C sequestration under cropping with manure application than under the farmland fallow without any fertilizer application. In the 1 m soil profiles, SOC levels decreased with soil depth with a major part (around 60–71%) being distributed in the 0–40 cm layer, whereas different practices led to great differential of SOC distribution. The CMC had the highest SOC levels (47.3 Mg ha −1 ) in the topsoil (0–20 cm) among the four systems. Meanwhile, maize cropping system (e.g. CMC and MSR) promoted more SOC allocation in >40 cm soil layers. Moreover, cropping pattern also differently influenced the formation and transformation of soil aggregates and the distribution of SOC in the aggregates. Macro-sized aggregate and the associated C (18.6 Mg ha −1 ) dominated in the FALL, while the micro-sized fractions (44.0% and 52.5%, respectively) and corresponding associated C (14.8 Mg ha −1 and 19.2 Mg ha −1 , respectively) were maximized in the MSR and CSC. The CMC had the greatest silt + clay-sized aggregate fraction (42.0%) and associated C in the macro- (13.4 Mg ha −1 ) and silt + clay-sized aggregate (12.9 Mg ha −1 ) fractions when compared with the MSR and CSC. Thus, maize–soybean rotation may be not the best cropping practice for C sequestration in the rainfed farmland Mollisol (Cumulic Hapludoll) in Northeast China, and intensive cropping with manure application can sustain the soil fertility for a long-term with high crop yield.

The processes of the organic matter (OM) mineralization in forest soils developed under temperate continental (Moscow oblast, Russia), Mediterranean (the central and western parts of Spain), and tropical monsoon (southern Vietnam) climates were studied under laboratory conditions. The potential and specific rates of the OM mineralization (PR min and PR min/Corg, respectively), the ecophysiological parameters of the microbial communities status (Cmic, qCO2, and Cmic/Corg), and the sensitivity of the rate of the OM mineralization to the rise in temperature were evaluated by the temperature coefficients (Q 10) determined in the humus horizons (0–10 cm, without forest litter). The average values of PR min for the climatic zones decreased in the following order: Mediterranean (57.1 ± 10.6 mg C/kg per day) > temperate continental (23.8 ± 7.1 mg C/kg per day) > tropical monsoon (10.4 ± 1.6 mg C/kg per day). The lowest resistance of the soil OM to mineralization as evaluated by the PR min/Corg values was found in the Albeluvisol and Phaeozem of the temperate continental climate and in the Acrisol of the Mediterranean climate. The highest Q 10 coefficients were attributed to the OM mineralization in the forest soils of the temperate continental climate. This allowed us to conclude that the observed and expected climate changes with an increase in the mean annual air temperature should lead to the maximum intensification of the OM mineralization processes in the forest soils of northern regions.

Common bean ( Phaseolus vulgaris L.) is one of the most important grain legumes in East Africa, but its yield has remained below the genetic potential. Declining soil fertility is among the primary constraints to bean production in most East African bean producing regions. Often existing recommendations are generic and inept to guide farm level decision making on nutrient replenishment. A greenhouse nutrient omission study was conducted to determine the limiting nutrients in three soils of Masaka District, commonly cropped to beans: “ Liddugavu ” a Phaeozem, “ Limyufumyufu ” a Cambisol and “ Luyinjayinga ” an Umbrisol soil. Nine treatments; (i) complete nutrient treatment, (ii) N omitted, (iii) P omitted, (iv) K omitted, (v) Mg omitted, (vi) S omitted, (vii) Ca omitted, (viii) Micronutrients omitted and (ix) control without nutrients. Each treatment was randomly assigned to the three soils and replicated three times using a completely randomised design. Nitrogen, phosphorus and potassium were limiting nutrients for bean production in Umbrisol (Luyinjayinja) while in Cambisol (‘ Limyufumyufu ), common bean production was most limited by soil acidity. The performance varied with soil types, with beans grown on the Phaeozem registering greater leaf number and growth, confirming both scientist’s and local farmer’s knowledge that this soil has greater potential than the other two soils. Key words: Cambisol, Phaeozem, Phaseolus vulgaris , Umbrisol

Whether production of winter wheat is stable without any fertilizer input on Greyic Phaeozem in the Czech Republic still remains unsolved. Phaeozems represent 3% of soils in Europe and they are particularly common in wet steppe regions. In this paper, the yield of winter wheat over 50 years of farmyard manure (FYM), N, P and K fertilizer application (12 treatments altogether) was analyzed in the Caslav Crop Rotation Experiment (CCRE), which was established in 1955 in a sugar beet growing area (mean annual precipitation and temperature 555 mm and 8.9 °C, respectively). In the unfertilized control treatment, low plant available P and suitable K concentrations were recorded after 50 years. The annual yield growth (AYG) of grain was positive, even in the control treatment without any fertilizer input. The mean AYG ranged from 24.9 kg ha −1 in the control treatment to 73.6 kg ha −1 following the application of 119 kg N ha −1 . In the first two decades of the experiment, there was no significant effect of treatment on grain yield. The increase in grain yield per 1 kg of applied N was 20.1 kg ha −1 in the last decade of the experiment. The mean grain yields of long-straw and short-straw varieties were 3.8 and 5.5 t ha −1 , respectively. In the control, the grain yields were 4.8, 4.1 and 3.3 t ha −1 after legumes, root crops and cereals, respectively. To summarize the 50 years of results of winter wheat production in the CCRE, grain yield was most influenced by variety, followed by mineral fertilizers, the preceding crop and only moderately by FYM application. The highest grain yields were recorded in treatments with the highest N application rate. The long-term stability of winter wheat production on Greyic Phaeozem can be expected under a crop rotation system with legumes and root crops, even without any fertilizer input.

The effects of soil type and organic material quality on the microbial biomass and functional diversity of cropland soils were studied in a transplant experiment in the same climate during a 1-year field experiment. Six organic materials (WS: wheat straw, CS: corn straw, WR: wheat root, CR: corn root, PM: pig manure, CM: cattle manure), and three contrasting soils (Ferralic Cambisol, Calcaric Cambisol and Luvic Phaeozem) were chosen. At two time points (at the end of the 1st and 12th months), soil microbial biomass carbon (C) and nitrogen (N) (MBC and MBN) and Biolog Ecoplate substrate use patterns were determined, and the average well color development and the microbial functional diversity indices (Shannon, Simpson and McIntosh indices) were calculated. Organic material quality explained 29.5-50.9% of the variance in MBC and MBN when compared with the minor role of soil type (1.4-9.3%) at the end of the 1st and 12th months, and C/N ratio and total N of organic material were the main parameters. Soil properties, e.g., organic C and clay content were the predominant influence on microbial functional diversity in particular at the end of the 12th month (61.8-82.8% of the variance explained). The treatments of WS and CS significantly improved the MBC and microbial functional diversity indices over the control in the three soils in both sampling periods (P < 0.05). These results suggest that the application of crop straw is a long-term effective measure to increase microbial biomass, and can further induce the changes of soil properties to regulate soil microbial community.

Long-term stationary fertilizer trials were performed at three different sites in order to study the subsequent effects of manure and full mineral fertilization. Dry matter yields of winter wheat grown after red clover were evaluated over the years 2003–2006. In the nil variant without any fertilization for the past 47–51 years, the basic grain yields were decreasing with the higher altitude. Three-year average yields varied from 3.39–8.09 t ha−1. The site productivity accounted for almost 80% in the Greyic Phaeozem and only about 53% in the Stagno-Gleyic Cambisol. The effect of mineral fertilization was the highest in the Stagno-Gleyic Cambisol, up to about 39%. The effect of weather conditions in individual years strongly differed in individual sites. The results have confirmed a complex of effects and interactions among various factors that affect winter wheat grain yields.