Meta-analysis of nutrient budgets in organic farms across Europe

Nutrient supply to organic farms is a highly discussed topic in Europe, due to the restricted availability of external fertilizer resources and the use of contentious inputs. To optimize the flow of nutrients throughout the organic farming system, it is firstly necessary to obtain valid data on the nutrient status of organic farms. Nutrient budgets are a valid tool to investigate the nutrient demand or surplus of a system. However, there is currently no comprehensive overview of nutrient budgets of European organic farms. We therefore carried out a meta-analysis on 56 individual studies that reported either farm-gate or soil-surface budgets. The analysis showed an imbalance between nutrients, a general surplus of nitrogen (45 kg N ha-1 year-1 [95%-confidence interval (CI): 30, 61]), magnesium (16 kg Mg ha-1 year-1 [-9, 40]) and sulphur (45 kg S ha-1 year-1 [-29, 118]), a balanced phosphorus budget (0 kg P ha-1 year-1 [-2,2]), and a deficit for potassium (-12 kg K ha-1 year-1 [-21, -3]). We observed large differences between farms that could be partly explained by farm type and budgeting method. Arable and mixed farms showed lower nitrogen, phosphor, magnesium and sulphur budgets than dairy/beef farms or even vegetable farms, while all farm types besides dairy/ beef farms showed deficits for K budgets. Further, farm-gate budget studies yielded higher budgets than soil surface budgets. Variations between studied countries could also be detected, but the coverage and comparability is low due to differences in studied farm types and budgeting method

Recycled fertilizer for organic farming – assessing the effect on soil fertility and associated risks with potentially toxic elements

Introduction There is a large political motivation goal in the EU to increase organic farming area to 25%. However, for this, additional nutrients, preferably from recycled sources are needed. Before their wide use in organic farming concerns about contamination with potentially toxic elements (PTEs) and their influence on soil fertility must be assessed. In this study, the effect of recycled fertilizers from urban waste on crop yield, nutrient balances, soil fertility (especially soil nitrogen and carbon), and risk of contamination with PTEs were examined. Therefore, data from three long-term (>20 years) were analysed and combined with a model simulation exercise to gain more insight into the nitrogen (N) and carbon (C) cycle. Methodology Data from three long-term field trials using different recycled fertilizers, including compost from household and green waste, human urine, and sewage sludge was analysed. The first trial investigates different compost application rates in combination with mineral fertilization and was established in 1997 at the research station Heidfeldhof, South Germany. The second trial compares different application rates of sewage sludge and was established 1981 in Speyer, Germany. The third trial is called CRUCIAL and was established in 2002 at the station Taarstrup, Denmark. It compares compost from household and green waste, human urine, and sewage sludge to mineral fertilization and cattle manures. Crop yield, and soil parameters like soil carbon, soil N, phosphorus, potassium, and PTE content were collected and analysed. The results of the CRUCIAL trial were used to calibrate the soil-plant-atmosphere model DAISY which in turn was used to estimate water, C and N flows. Results and discussion Recycling urban waste into fertilizers can serve as a viable source of nutrients. In terms of nitrogen recovery rates, sewage sludge and human urine performed similarly to cattle slurry with N recovery rates of about 0.5 – 0.6, while household waste compost showed similar values to straw-rich animal manures with N recovery rates of about 0.3. After field application, the model simulation estimated nitrogen losses ranging from 34-55% with nitrate leaching being the primary loss pathway. Compost and cattle manure resulted in slightly smaller total nitrogen losses. Further, higher soil nitrogen accumulation of about 25% of the applied nitrogen were associated with compost and manure application. Compost also had the highest soil carbon sequestration of about 0.36, while cattle manure showed 0.12, sewage sludge 0.09, and cattle slurry 0.02. Concerns about contaminants, such as PTEs, exist, particularly with compost and sewage sludge fertilization, which can increase PTE levels in the soil. Yet, not above the precautionary threshold levels. Additionally, significant changes in crop PTE uptake were rare probably due to low PTE bioavailability. Conclusion The organic nutrient management in Europe requires more external nutrient inputs, and recycled fertilizers from urban wastes are an adequate source to close the nutrient gap and substitute animal manures from conventional origin. They additionally can increase soil carbon and nitrogen levels. Overall, the use of recycled fertilizers from urban waste is a promising solution, with negligible risks associated with PTEs to human health and the soil environment. Acknowledgements This study was conducted within the RELACS project ‘Replacement of Contentious Inputs in Organic Farming Systems’, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 773431

Patterns of Social Inequalities in Access to Higher Education in France and Germany

This article explores social selectivity in access to tertiary education in France and Germany in the period from 1980 to 2000. Results of multinomial logistic regression models show that access to different postsecondary institutions is characterized by marked social background effects in both countries. Depending on the type of tertiary institution we consider in France or Germany, social selectivity into fields of study is also observed. Overall, there is no indication for substantial changes in the pattern of inequality in access to tertiary education in either country during the past two decades

Nitrogen fertiliser value of digestates and untreated cattle slurry differs in organic and conventional crop management

Introduction One main obstacle to sustainable nutrient management in organic farming is the scarcity of nutrients. Further, commonly used nutrient sources in organic farming like composts or straw-rich animal manure show low nitrogen (N) fertilizer value. Anaerobic co-digestion of animal manures with biomass from green manures could increase the N fertilizer value of the animal manures while the addition of green manure would result in a higher quantity of fertilizers available in organic farming. Yet, studies investigating N fertilizer values under organic management are scarce. Therefore, this study aimed to determine the N fertilizer value of different products from anaerobic digestion (digestates, separated liquid fraction of digestates) as well as cattle manure and mineral fertilization under organic management. In addition, the difference in fertilizer value due to application timing (before vs. after ploughing) and crop management (organic vs. conventional) was tested. Methodology Two field studies were performed on loamy sand soil at the research station Foulumgaard (56o49’N, 09o58’E). Study 1 compared the effect of digestates (co-digestion of cattle slurry and clover grass silage), and liquid fraction from separated digestates with the effect of an unfertilized control, cattle slurry, and mineral fertilization on spring barley yield in two consecutive years under organic management. Study 2 investigated the differences in the fertilizer value of digestates (2on cattle slurry), and cattle slurry due to application timing (before vs. after ploughing), N dose (100 vs. 200 kg N ha-1), and management (organic vs. conventional) in spring barley. The fertilizer value was calculated as N fertilizer replacement value (NFRV) for grain N and total N yield. NFRV is estimated as shown in the equations belowfrom the N use efficiency (NUE) of manures relative to NUE of mineral fertilizer N (determined as the slope of the mineral N response curve). (1) NUE=(Nuptake fertilized – Nuptake unfertilized)/Napplied*100% (2) NFRV=NUEmanure/NUEmineral*100% Results and discussion Study 1 revealed that cattle slurry, digestates, and the liquid digestates fraction had all high NFRV between 80% and 90% (based on grain N yield under organic management). Hence, co-digestion of cattle slurry with biomass from green manures can increase the quantity of digestates without lowering the quality. Within the nutrient-limited system of arable organic farming, this could increase the nutrient supply and also be a meaningful use of the biomass from green manures. The separation of the liquid fraction did not result in a higher NFRV. However, it lowered the phosphorous content relative to the N content which can prevent nutrient imbalances, when digestates are used as the only source of N. Study 2 revealed an increase of > 10% points NFRV due to anaerobic digestion (cattle slurry vs. digestate; F(1,49)=96.00, p<0.001). It also showed that injection after ploughing compared to injection before ploughing, as often done in practice, can considerably increase the NFRV independent of the kind of fertilizer by around 8% points (F(1,49)=24.82, p<0.001). This was probably due to a placement effect when the slurry band was untouched after injection. Further, the estimated NFRV was 13% points higher by organic than conventional management (F(1,3)=36.11, p=0.009) which could have caused the relatively high NFRV measured in study 1. It can be explained by a 12% points lower NUE of mineral fertilization under organic management compared to conventional management (t30=7.06, p<0.001). Yet, the NUE of cattle slurry and digestates were not affected by the type of management (t22=1.37, p=0.19 and t22=0.54, p=0.60, respectively). Conclusion Anaerobic digestion can be a valid tool for increasing nutrient efficiency and availability in organic farming. However, when it comes to evaluating the NFRV of organic manures, the application technique and the management of the experiment should be considered. Further research is needed to determine the reasons for a reduced NUE of mineral fertilization while organic manures seemed to be unaffected. Acknowledgements This research was conducted within the ClimOptic project financed by ICROFS Organic RDD 4 through the Green Development and Demonstration Programme under the Danish Ministry of Environment and Food

The COVID-19 Crisis: Using the Cracks in Neoliberalism for Social Transformation Towards a More Just Society

Within the current COVID-19 pandemic, cracks observed in neoliberal dominant global economic paradigms reveal how austerity policies have crippled crucial social safety nets, such as health care, with capitalism continuing to adversely impact our climate with ad infinitum extraction of resources for overconsumption. In examining these associations, this collaborative paper critically applies social theories to explore ideas and approaches to creating transformative social change, in an effort to move towards a more just and sustainable society in the context of the COVID-19 pandemic and other ongoing systemic crises. The paper presents the pandemic as a social crisis and explores theories of social justice and how they might be applied within the context of neoliberal capitalism, also known as neoliberalism. The authors of this paper argue that to move towards a just society, social transformation is needed, informed by the theories of decoloniality and intersectionality. A conceptual model is presented that demonstrates how these theories can be woven together to inform community psychology action and research, addressing COVID-19 specifically. Possibilities for transformation in the areas of mental health and climate justice are also presented. Finally, recommendations for community psychology researchers seeking social transformation, while navigating this challenging and complex new reality, are shared

The COVID-19 Crisis: Using the Cracks in Neoliberalism for Social Transformation Towards a More Just Society

Within the current COVID-19 pandemic, cracks observed in neoliberal dominant global economic paradigms reveal how austerity policies have crippled crucial social safety nets, such as health care, with capitalism continuing to adversely impact our climate with ad infinitum extraction of resources for overconsumption. In examining these associations, this collaborative paper critically applies social theories to explore ideas and approaches to creating transformative social change, in an effort to move towards a more just and sustainable society in the context of the COVID-19 pandemic and other ongoing systemic crises. The paper presents the pandemic as a social crisis and explores theories of social justice and how they might be applied within the context of neoliberal capitalism, also known as neoliberalism. The authors of this paper argue that to move towards a just society, social transformation is needed, informed by the theories of decoloniality and intersectionality. A conceptual model is presented that demonstrates how these theories can be woven together to inform community psychology action and research, addressing COVID-19 specifically. Possibilities for transformation in the areas of mental health and climate justice are also presented. Finally, recommendations for community psychology researchers seeking social transformation, while navigating this challenging and complex new reality, are shared

Meta-analysis of nutrient budgets in organic farms across Europe

Nutrient supply to organic farms is a highly discussed topic in Europe, due to the restricted availability of external fertilizer resources and the use of contentious inputs. To optimize the flow of nutrients throughout the organic farming system, it is firstly necessary to obtain valid data on the nutrient status of organic farms. Nutrient budgets are a valid tool to investigate the nutrient demand or surplus of a system. However, there is currently no comprehensive overview of nutrient budgets of European organic farms. We therefore carried out a meta-analysis on 56 individual studies that reported either farm-gate or soil-surface budgets. The analysis showed an imbalance between nutrients, a general surplus of nitrogen (45 kg N ha-1 year-1 [95%-confidence interval (CI): 30, 61]), magnesium (16 kg Mg ha-1 year-1 [-9, 40]) and sulphur (45 kg S ha-1 year-1 [-29, 118]), a balanced phosphorus budget (0 kg P ha-1 year-1 [-2,2]), and a deficit for potassium (-12 kg K ha-1 year-1 [-21, -3]). We observed large differences between farms that could be partly explained by farm type and budgeting method. Arable and mixed farms showed lower nitrogen, phosphor, magnesium and sulphur budgets than dairy/beef farms or even vegetable farms, while all farm types besides dairy/ beef farms showed deficits for K budgets. Further, farm-gate budget studies yielded higher budgets than soil surface budgets. Variations between studied countries could also be detected, but the coverage and comparability is low due to differences in studied farm types and budgeting method

Farm gate nutrient budgets in organic farms – a case study in Germany

Low nutrient availability, especially of nitrogen (N) and phosphorus (P), is one of the major constraints on crop yields in organic farming. We investigated the nutrient supply to 20 organic farms in Germany. The investigation showed, that the hgher the reliance on legumes for nitrogen fertilization, the higher is the risk of negative phosphour and potassium budgets

Reliance on Biological Nitrogen Fixation Depletes Soil Phosphorus and Potassium Reserves

Limited nutrient availability is one of the major challenges in organic farming. Little is known about nutrient budgets of organic farms, the underlying factors or effects on soil fertility. We therefore assessed farm gate nutrient budgets for nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg) and sulfur (S) of 20 organic farms in Germany and analyzed their soil nutri-ent status. In average, the budgets showed a surplus of N (19 kg ha−1), K (5 kg ha−1), S (12 kg ha−1), and Mg (7 kg ha−1), and a deficit of P (−3 kg ha−1). There was, however, high variability between farms (e.g. standard deviation up to ± 36 kg N ha−1), which was mainly explained by different degrees of reliance on biological N fixation (BNF) as N source. When farms obtained more than 60% of their N input through BNF, they had deficits of P (mean −8 kg P ha−1) and K (mean −18 kg K ha−1). Nutrient status of most soils was within the ad-vised corridor, but for P, K and Mg, 10–15% of fields were lower and 45–63% were higher than advised. Extractable soil nutrient contents did not correlate with the nutrient budgets, inputs or outputs. Only extractable soil P increased with increasing P inputs and outputs. Fur-thermore, a decrease in extractable soil P was detected with a prolonged history of organic farming, indicating a risk of soil P mining in organic farming systems. In conclusion, the study revealed nutrient imbalances in organic farming and pointed to P and K scarcity as a major challenge for organic farms with high reliance on BNF in the long term