TY  - JOUR
AB  - Phosphorus (P) is an essential macronutrient element for plant growth and development. Its limited availability makes alternative P sources crucial for fertilizer production. This study investigated the effects of three recycling-derived fertilizers with varying P solubility on microbial nutrient turnover at two fields in central Germany, Kiebitzbreite and Schmatzfelder Breite, which differ in management practices and soil characteristics. Samples were collected during the stem elongation stage of winter wheat from bulk soil and rhizosphere. Fertilization treatments included traditional triple superphosphate (TSP) and a no-P control (P0) for comparison. The abundance of microorganisms involved in P and Nitrogen (N) turnover was assessed by quantitative real-time PCR. Potential acid and alkaline phosphatase activity, mycorrhizal colonization rate, Carbon (C) to P, N to P ratios in the soil and the plant, and water-extractable P were measured. Although all treatments received the same amount of P, the differing solubilities of the fertilizers significantly affected water-extractable P levels, while nutrient ratios in the plant biomass remained comparable among sites and fertilizer treatments. However, the microbial strategies for maintaining P levels varied significantly across the sites. At the Kiebitzbreite, the site with silty loam texture and deep plowing, high ratios of available C and N to P in the soil were accompanied by high alkaline phosphatase activity and a larger abundance of arbuscular mycorrhizal fungi in the rhizosphere. Conversely, P solubilization was more pronounced at Schmatzfelder Breite, a site with finer soil texture managed by deep chiseling. Notably, the fertilization treatments influenced not only the abundance of bacteria catalyzing P turnover but also those catalyzing major steps of the N cycle, especially at Schmatzfelder Breite, where higher P solubility led to increased bacteria involved in N mineralization. This non-targeted effect on N cycling underscores the importance of fertilizer type, beyond just P supply, in influencing broader nutrient turnover dynamics. Our findings suggest that recycling-derived P fertilizers are promising alternatives to conventional P sources, though their on-farm impacts on microbial nutrient turnover vary significantly with site conditions and management.
AU  - Thaqi, S.K.*
AU  - Siani, R.
AU  - Chiba, A.*
AU  - Vitow, N.*
AU  - Baum, C.*
AU  - Leinweber, P.*
AU  - Panten, K.*
AU  - Schloter, M.
AU  - Schulz, S.
C1  - 73600
C2  - 57132
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Effects of novel P fertilizers on microbial abundance related to N and P cycling in two on-farm systems.
JO  - Agric. Ecosyst. Environ.
VL  - 385
PB  - Elsevier
PY  - 2025
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Space-for-time substitution, also known as pseudo chronosequence (PCS), is often used as a method to assess temporal changes in ecosystems without having to wait for the time span that the study is supposed to cover. However, the suitability of PCS studies is often questioned because convergent development of spatially separated plots over time is rarely guaranteed even under optimal conditions. To assess whether the PCS approach is justified and suitable, we studied the nematode soil food web development of free-living nematodes and biological and chemical soil components related to C and N mobilization (CO2 and NO3-) and immobilization (microbial and soil organic carbon), in a PCS focusing on the critical early reclamation period of four years after open-cast lignite mining, and compared it with a real chronosequence (RCS) of a reclamation site monitored over four years. We hypothesized that: (I) nematode-derived indices indicate the same course of nematode soil food web development in the PCS and RCS, tolerating a range of variability in weather conditions, soil components, and management; (II) the development of nematode soil food web indicators can provide information on the status of C and N retention and cycling in the reclaimed soil. Our results show that the PCS and RCS approaches reach similar conclusions, indicating a rapidly developing nematode soil food web during the first four years after reclamation. They also suggest that the nematode faunal profile may indicate the status of C and N retention and cycling in reclaimed soil. Overall, it can be concluded that the PCS approach successfully predicts the temporal development of the nematode soil food web in loess-dominated reclaimed mining soils, even when there is a range of variability in soil components and management conditions.
AU  - Reichel, R.*
AU  - Hänsch, M.*
AU  - Schulz, S.
AU  - Martins, R.B.
AU  - Schloter, M.
AU  - Brüggemann, N.*
C1  - 71491
C2  - 56128
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Comparing a real and pseudo chronosequence of mining soil reclamation using free-living nematodes to characterize the food web and C and N dynamics.
JO  - Agric. Ecosyst. Environ.
VL  - 376
PB  - Elsevier
PY  - 2024
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Phosphorous (P) is one of the most critical macronutrient elements for plant growth, yield and quality. However, natural P sources are finite and an improved P recycling is necessary. Therefore, we investigated the effect of bone char (BC) and bone char plus (BC ) as recycling products and alternative P fertilizers, on the abundance of microorganisms, which catalyze major steps in P turnover in a field experiment in Central Germany. The effects were compared to conventional triple super phosphate (TSP) and no P fertilization. Samples were analyzed from soils with three different initial soil P concentrations (very low, low, optimal) and three times during winter wheat cultivation (stem elongation, heading, ripening) to reveal interactions of fertilizers and soil properties. Abundances of microorganisms involved in P uptake, solubilization and mineralization were assessed by quantitative real time PCR (qPCR). Additionally, potential acidic- and alkaline phosphatase activity, water extractable P and plant available P were measured. Bacterial strategies to maintain P pools differed among the treatments. While the addition of BC  increased the solubilization potential, the low P concentration in control plots and slow release of P from BC favor P recycling from biomass and P inducible uptake systems, which is displayed by either high abundance bacteria harboring the phoD or pstS gene, respectively. All effects were most pronounced at the time of heading and in soils with optimal initial P concentration. It can be assumed that sulfurization of bone char (BC ) influences bacterial P turnover by promoting solubilization of the fertilizer thereby increasing P availability for plants. Additionally, plant development stage and initial soil P concentrations hamper the effect of BC and BC  on bacterial P turnover. plus plus plus plus
AU  - Grafe, M.
AU  - Kurth, J.
AU  - Panten, K.*
AU  - Raj, A.D.
AU  - Baum, C.*
AU  - Zimmer, D.*
AU  - Leinweber, P.*
AU  - Schloter, M.
AU  - Schulz, S.
C1  - 61923
C2  - 50508
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Effects of different innovative bone char based P fertilizers on bacteria catalyzing P turnover in agricultural soils.
JO  - Agric. Ecosyst. Environ.
VL  - 314
PB  - Elsevier
PY  - 2021
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Grazed alpine pastures have shaped landscapes of the European Alps for millennia, but have partially been abandoned since the 1950s. Re-grazing of abandoned pastures could preserve this cultural landscape with its high species diversity, but also alter soil carbon and nitrogen cycles, as well as microbial communities, potentially affecting ecosystem services (e.g., water purification, carbon and nitrogen storage). However, there is a lack of information on the resistance of soil characteristics to re-grazing effects. After characterising the distribution of vegetation types of an abandoned pasture in the German Alps, we investigated short-term effects of re-grazing on soil organic carbon and nitrogen biochemistry, soil microbial communities, and water quality along a gradient of grazing intensity. The abandoned grassland studied presented a remarkably high diversity of species and habitats even 60 years after abandonment. It was also found to be particularly rich in terms of microbial biomass, as well as in soil carbon and nitrogen. A few months after re-grazing started, extractable organic carbon, gross nitrogen mineralisation rates and inorganic nitrogen concentrations were increased only in intensively grazing-affected areas with bare soil (i.e. concentration of cows with excreta inputs), which insignificantly contributed to the overall area. Re-grazing did not affect the microbial abundance, whatever the grazing intensity, but induced a community shift towards a smaller proportion of fungi compared to bacteria and an increase of ammonia oxidizers (archaea/bacteria) under bare soil conditions. Concentrations of dissolved organic carbon and nitrate in the draining creek remained very low. Overall, re-grazing of pastures in the first season had very limited effects on microbial communities and associated carbon and nitrogen turnover and concentrations, highlighting the resistance of the studied alpine soils to extensive re-grazing. Our results indicate how to develop sustainable management strategies that preserve alpine pastures from degradation.
AU  - Vidal, A.*
AU  - Schucknecht, A.*
AU  - Toechterle, P.*
AU  - Andrade Linares, D.R.
AU  - Garcia-Franco, N.*
AU  - Von Heßberg, A.*
AU  - Krämer, A.*
AU  - Sierts, A.*
AU  - Fischer, A.*
AU  - Willibald, G.*
AU  - Fuetterer, S.*
AU  - Ewald, J.*
AU  - Baumert, V.*
AU  - Weiss, M.*
AU  - Schulz, S.
AU  - Schloter, M.
AU  - Bogacki, W.*
AU  - Wiesmeier, M.*
AU  - Mueller, C.W.*
AU  - Dannenmann, M.*
C1  - 59228
C2  - 48761
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - High resistance of soils to short-term re-grazing in a long-term abandoned alpine pasture.
JO  - Agric. Ecosyst. Environ.
VL  - 300
PB  - Elsevier
PY  - 2020
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Organic farming is gaining importance in view of its beneficial effects on soil quality, environmental performance and biodiversity. However, it is still unclear how organic management performs over time and whether the duration of organic management influences crop yield and ecosystem functioning. Here we compared 34 fields in Swiss farms assigned to four groups: 1) conventionally managed farms; 2) farms in transition to organic farming (in the 1st - 3rd year); 3) farms converted moderately long ago (9-13 years); and 4) farms subjected to long-term organic farming (15-32 years). We selected one field per farm and examined in two subsequent years whether management practices (conventional vs. organic farming) and the duration of organic management affected crop yield, weed cover, soil fertility and biodiversity as well as the overall system performance, assessed as ecosystem multifunctionality. Maize yield (-6.0%) and wheat yield (-22.2%) decreased in organic compared to conventional fields. However, the duration of organic management did not affect crop yield. There was also no effect of the duration of organic management on weed cover but it was much higher under organic management, with mean values of 33.0% in organic compared to 2.0% in conventional fields in maize, and 13.4% compared to 1.2% in wheat, respectively. Soil fertility and microbial activities were not significantly different between management practices, which might be due to the large variation among fields. Root colonization of arbuscular mycorrhizal fungi increased (+19.7%) under organic management in wheat. Overall, this study demonstrates a rapid shift of agro-ecological functions after conversion to organic farming and that the duration of organic management has no impact on crop yield, weed cover and soil fertility.
AU  - Herzog, C.*
AU  - Honegger, A.*
AU  - Hegglin, D.*
AU  - Wittwer, R.*
AU  - de Ferron, A.*
AU  - Verbruggen, E.*
AU  - Jeanneret, P.*
AU  - Schloter, M.
AU  - Banerjee, S.*
AU  - van der Heijden, M.G.A.*
C1  - 57670
C2  - 47864
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Crop yield, weed cover and ecosystem multifunctionality are not affected by the duration of organic management.
JO  - Agric. Ecosyst. Environ.
VL  - 284
PB  - Elsevier
PY  - 2019
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Arable soils are a major source of the climate relevant trace gas nitrous oxide (N2O). Although N2O emissions from soils increase with the amount of N-fertilizer, there is still a lack of data for intensively fertilized systems, such as vegetable production. We investigated the effect of an ammonium sulfate nitrate (ASN) fertilization either placed or broadcast applied combined with a nitrification inhibitor (3,4-dimethylepyrazole phosphate (DMPP)) on soil surface N2O fluxes as compared to conventional broadcast ASN fertilization in a lettuce–cauliflower rotation over two years of measurement. Except for a lower cauliflower yield in the second experimental year with placed fertilization, no differences in yields between the fertilized treatments were observed. Annual cumulative N2O emissions of the conventionally fertilized treatment were 8.8 and 4.7 kg N2O-N ha−1 yr−1 for the first and second experimental year, respectively, indicating a high inter-annual variability. The addition of the nitrification inhibitor significantly reduced N2O emissions during the cropping season and also during the winter period, resulting in an annual reduction of 45 and 40% as compared to the conventionally fertilized (CONV) treatment. The reason for the lower N2O release in the DMPP treatment as compared to the conventionally fertilized treatment remained unclear. Since we did not find any significant differences in the mineral N pools during periods with distinctive inhibition, this can be ruled out as reason for the lower N2O release in the DMPP treatment. We found lower soil respiration in the DMPP treatment during several months starting about six weeks after fertilizer application. In contrast to the treatment with nitrification inhibitor, the placed fertilization as an N-depot (fertilizer bands inserted into the soil) did not reduce annual N2O emissions, although the ratio of ammonium (NH4+) to nitrate (NO3−) in the first weeks after N-application indicate inhibition of nitrification in the fertilizer depot. We assume that, even though NH4+ concentrations in the depots were high, toxicity was not sufficient for a complete inhibition of microbial activity in the surrounding of the depots, resulting in considerable N2O production. The emission factors calculated for CONV treatment were 1.6 and 0.8% for the first and second experimental year, respectively. For the treatment with nitrification inhibitor (NI), they were only 0.9 and 0.5%; for the treatment with placed fertilization as an N-depot (DEPOT) 2.0 and 0.8%. They were thus within the range proposed by the guidelines of the IPCC (2006). However, although the N-input related N2O emission factors were within the range proposed by the guidelines of the IPCC, the absolute N2O emissions from the intensively fertilized vegetable field were high. For effective, but environmentally sound vegetable production, a deeper understanding of nitrification inhibitory strategies is necessary.
AU  - Pfab, H.*
AU  - Palmer, I.*
AU  - Buegger, F.
AU  - Fiedler, S.*
AU  - Müller, T.*
AU  - Ruser, R.*
C1  - 7245
C2  - 29590
SP  - 91-101
TI  - Influence of a nitrification inhibitor and of placed N-fertilization on N2O fluxes from a vegetable cropped loamy soil.
JO  - Agric. Ecosyst. Environ.
VL  - 150
PB  - Elsevier
PY  - 2012
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Nitrous oxide (N2O) emissions from soil are characterized by strong emission pulses. Although several mechanisms are known to create them, pulses are difficult to predict. Currently there is no established systematic way to identify pulses from long-term static chamber measurement results. In this study we suggest a simple algorithm for pulse identification. The algorithm was applied on time series of N2O and carbon dioxide (CO2) fluxes from a field study on the long-term impact of fertilization and tillage practice. Between 4 and 9% of N2O values were pulse values; 20â??60% of total emission was emitted as pulses. Minimum tillage resulted in more pulses than plowing. In contrast, long-term averages of N2O losses from nitrogen (N) fertilizer were similar (3â??4%) for all management practices. N2O emissions per crop yield for increased fertilization practice were double the values for reduced fertilization practice independent of tillage practice. CO2 emission pulses were scarce and there was no significant effect of management practice on CO2 pulse probability.
AU  - Fuß, R.
AU  - Ruth, B.
AU  - Schilling, R.
AU  - Scherb, H.
AU  - Munch, J.-C.
C1  - 6735
C2  - 29179
SP  - 61-68
TI  - Pulse emissions of N2O and CO2 from an arable field depending on fertilization and tillage practice.
JO  - Agric. Ecosyst. Environ.
VL  - 144
IS  - 1
PB  - Elsevier
PY  - 2011
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Agriculture is one of the major anthropogenic methane source. However, emission inventories of agricultural soils are rather uncertain. One reason for this is the existence of small areas of very high biogeochemical fluxes (‘hot spots’), which are not incorporated into soil maps. Here a procedure for an upscaling of one man-made ‘hot spot’ is presented. In hummocky ground moraines of temperate-humid climate (Allgäu, Germany) erosion and subsequent sedimentation of topsoil material in wet footslope areas has led to very high emissions from depression margins (median annual flux=39 g CH4 m−2). These areas make up 7% of the region studied according to a digital terrain analysis based on a DEM 50. GIS-based modelling showed their regional and global relevance to be a result of the (i) unit area source strength, (ii) relative acreage of depression margins in catchments of hummocky landscapes, and (iii) global dimension of hummocky landscapes with closed depressions. First conservative estimates yielded methane emissions of 1.1 Gg (regional, Allgäu) and 2.5 Tg (global) from colluvial margins in similar landscapes, respectively.
AU  - Sommer, M.
AU  - Fiedler, S.*
AU  - Glatzel, S.*
AU  - Kleber,M.*
C1  - 3466
C2  - 21832
SP  - 251-257
TI  - First estimates of regional (Allgäu, Germany) and global CH4 fluxes from wet colluvial margins of closed depressions in glacial drift areas.
JO  - Agric. Ecosyst. Environ.
VL  - 103
IS  - 1
PY  - 2004
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Interactions between the diversity of primary producers (plants) and of decomposers (microbes and mesofaunal communities), the two key functional groups that form the basis of all ecosystems have major consequences on the functioning of agricultural ecosystems. Soil microorganisms control the transformation and mineralization of natural compounds and xenobiotics. The soil microbiota, existing in extremely high density and diversity, rapidly modify the energetic performance and activity rates to changing environmental conditions. Thus, the microbial consortium possesses the ability to accommodate environmental constraints by adjusting (i) activity rates, (ii) biomass, and (iii) community structure. These parameters are particularly important to take into consideration when evaluating soil quality. The present paper gives an overview about the possibilities to use bacterial and fungal populations as an indicator for soil quality. Furthermore also the applicability of nematodes for the determination of soil health will be discussed.
AU  - Schloter, M.
AU  - Dilly, O.*
AU  - Munch, J.-C.
C1  - 22219
C2  - 20933
SP  - 255-262
TI  - Indicators for evaluating soil quality.
JO  - Agric. Ecosyst. Environ.
VL  - 98
IS  - 1-3
PY  - 2003
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - In this paper the effects of precision farming were compared to conventional agricultural management estimating bacterial and fungal diversity and also microbial processes in the nitrogen cycle during the vegetation period of maize. The aim was to find parameters which can be used as indicators for sustainable soil quality. Two plots, a high yield and a low yield site, were selected in the two systems. It could be demonstrated that the microbial biomass and community structure of bacteria and fungi in the top soils were not influenced by precision farming. Microbial biomass was reduced during the summer month, due to the dryness and hot temperatures. The microbial community structure changed in late spring time probably due to the application of fertilizers and high amounts of root exudates in the rhizosphere.
      
      	The measured enzymatic activities however did not show only a seasonal variation with the highest measured values in spring and early summer, but also clear effects based on the investigated plot (high yield or low yield) and the used farming management system (conventional or precision). Proteolytic activity was significantly higher on the high yield plots at all measured times. Mainly on the low yield sites precision farming caused a higher proteolytic activity compared to the conventional management. Nitrification and denitrification activities were mainly effected after the application of N-fertilizer. Significant higher values were found on the low yield plots, where conventional farming was applied. The results indicate that the effectiveness of nitrogen turnover might be a good indicator for sustainable agriculture and soil quality.
AU  - Schloter, M.
AU  - Bach, H.-J.
AU  - Metz, S.
AU  - Sehy, U.
AU  - Munch, J.-C.
C1  - 22220
C2  - 20934
SP  - 295-304
TI  - Influence of precision farming on the microbial community structure and functions in netrogen turnover.
JO  - Agric. Ecosyst. Environ.
VL  - 98
IS  - 1-3
PY  - 2003
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Nitrous oxide emissions and selected soil properties in a high and a low yielding area of a maize field were monitored weekly over a 1-year period. In both the high and the low yielding area, N2O emissions from a treatment subject to site-specific N-fertilization were compared to a conventionally fertilized control.
      
      	Emission peaks were measured following N fertilization, rainfall, harvest, tillage and freeze-thaw cycles from all treatments in conditions favorable for denitrification. Between 80 and 90% of annual emissions were released between April and September. A value of 60% WFPS was identified as a threshold for the induction of elevated N2O emissions (>50 μg N2O-N m−2 h−1). A significant relationship (r2=0.41) between N2O flux rates and WFPS was found when neither soil nitrate contents nor temperature were limiting for microbial denitrification.
      
      	Mean cumulative N2O emissions from the control treatments in the high yielding area, located in a footslope position and thus receiving lateral water and nutrient supply, more than doubled those from the control treatments in the low yielding area in a shoulder position (8.7 and 3.9 kg N2O-N ha−1, respectively). Higher average WFPS in the high yielding area was identified as responsible for this difference.
      
      	The site-specific fertilized treatments in the low yielding area were supplied with 125 kg N fertilizer ha−1 as compared to 150 kg N fertilizer ha−1 (control treatments). This reduction resulted in 34% less N2O released in roughly 10 months following differentiated fertilization while crop yield remained the same. In the high yielding area, N fertilizer supply in the site-specific fertilized treatment was 175 kg N ha−1 as compared to 150 kg N ha−1 in the control. Neither crop yield nor N2O emissions were significantly affected by the different fertilizer rates.
AU  - Sehy, U.
AU  - Ruser, R.
AU  - Munch, J.-C.
C1  - 10391
C2  - 21204
SP  - 97-111
TI  - Nitrous oxide fluxes from maize fields : Relationship to yield, site-specific fertilization and soil conditions.
JO  - Agric. Ecosyst. Environ.
VL  - 99
IS  - 1-3
PB  - Elsevier
PY  - 2003
SN  - 0167-8809
ER  - 

TY  - JOUR
AB  - Agricultural practices contribute to emissions of the greenhouse gases CO2, CH4 and N2O. The aim of this study was to determine and discuss the aggregate greenhouse gas emission (CO2, CH4 and N2O) from two different farming systems in southern Germany. Farm A consisted of 30.4 ha fields (mean fertilization rate 188 kg N per ha), 1.8 ha meadows, 12.4 ha set-aside land and 28.6 adult beef steers (year-round indoor stock keeping). Farm B followed the principles of organic farming (neither synthetic fertilizers nor pesticides were used) and it consisted of 31.3 ha fields, 7 ha meadows, 18.2 ha pasture, 5.5 ha set-aside land and a herd of 35.6 adult cattle (grazing period 6 months). The integrated assessment of greenhouse gas emissions included those from fields, pasture, cattle, cattle waste management, fertilizer production and consumption of fossil fuels. Soil N2O emissions were estimated from 25 year-round measurements on differently managed fields. Expressed per hectare farm area, the aggregate emission of greenhouse gases was 4.2 and 3.0 Mg CO2 equivalents for farms A and B, respectively. Nitrous oxide emissions (mainly from soils) contributed the major part (about 60%) of total greenhouse gas emissions in both farming systems. Methane emissions (mainly from cattle and cattle waste management) were approximately 25% and CO2 emissions were lowest (circa 15%). Mean emissions related to crop production (emissions from fields, fertilizer production, and the consumption of fossil fuels for field management and drying of crops) was 4.4 and 3.2 Mg CO2 equivalents per hectare field area for farms A and B, respectively. On average, 2.53% of total N input by synthetic N fertilizers, organic fertilizers and crop residues were emitted as N2O-N. Total annual emissions per cattle unit (live weight of 500 kg) from enteric fermentation and storage of cattle waste were about 25% higher for farm A (1.6 Mg CO2 equivalents) than farm B (1.3 Mg CO2 equivalents). Taken together, these results indicated that conversion from conventional to organic farming led to reduced emissions per hectare, but yield-related emissions were not reduced.
AU  - Flessa, H.*
AU  - Ruser, R.
AU  - Dörsch, P.*
AU  - Kamp, T.
AU  - Jimenez, M.A.
AU  - Munch, J.-C.
AU  - Beese, F.*
C1  - 10392
C2  - 20384
SP  - 175-189
TI  - Integrated evaluation of greenhouse gas emissions (CO2, CH4, N2O) from two farming systems in Southern Germany.
JO  - Agric. Ecosyst. Environ.
VL  - 91
IS  - 1-3
PB  - Elsevier
PY  - 2002
SN  - 0167-8809
ER  -