Soil degradation is a major challenge in Sub-Saharan Africa, where integrated soil fertility management has been promoted to restore productivity. A long-term experiment (1972\uffe2\uff80\uff931992) run in Benin consisted of two phases: a depletion phase (1972\uffe2\uff80\uff931980) with varying levels of mineral and organic fertilisation, and a regeneration phase (1981\uffe2\uff80\uff931992) where all plots received full fertilisation and organic matter additions. Soils were sampled at 0\uffe2\uff80\uff9320\uffc2\uffa0cm depth in 1973, 1974, 1982, and 1989 to assess fertility changes. Mineral fertilisation (N, P, K) and plant biomass management (crop residue retention and biomass additions) significantly influenced seed cotton and maize grain yields during the depletion phase. Soil organic carbon declined consistently in all treatments during depletion but remained stable during regeneration. The long-term effect was evident only in seed cotton yield during depletion. In contrast, due to high variability, maize grain yield showed no consistent trend. The combined use of organic resources and mineral fertilisers helped maintain crop productivity but led to declining soil chemical properties in this Ferralsol. The analysis of this outdated yet unpublished dataset shed light on how long-term soil depletion effects persist over time, even when soil fertility management is restored, indicating a sort of \uffe2\uff80\uff98soil memory\uffe2\uff80\uff99. The persistence of these effect suggests that regenerative interventions must begin before critical thresholds of degradation are crossed. Future research should focus on alternative measures to restore/maintain soil fertility not evaluated in this experiment, such as conservation tillage or legume integration, to provide long-term benefits for smallholder farmers facing soil fertility challenges.This study assessed how digestate and the liquid fraction (LF) of digestate would perform as candidate RENURE fertilisers (recovered nitrogen from manure) in nitrate vulnerable zones under the proposed criteria of the Joint Research Centre, namely, (i) a mineral nitrogen to total nitrogen ratio \uffe2\uff89\uffa5 90% (Nmin:TN \uffe2\uff89\uffa5 90%) or a total organic carbon to TN ratio \uffe2\uff89\uffa4 3 (TOC:TN \uffe2\uff89\uffa4 3); (ii) limits of \uffe2\uff89\uffa4300 copper (Cu) mg kg\uffe2\uff88\uff921 and \uffe2\uff89\uffa4800 Zinc (Zn) mg kg\uffe2\uff88\uff921. These criteria were applied to unpublished data (n = 2622) on digestate compositional properties, further amended with data from the literature (n = 180); digestate analysis from seven full-scale biogas facilities (n = 14); and biogas industry stakeholders (n = 23). The results showed that Cu and Zn mostly met the criteria, with compliance rates of 94.7% (of 1035 entries) and 95.0% (of 1038 entries), respectively. Just above 5% (of 1856 entries) met the Nmin/TN \uffe2\uff89\uffa5 90% criterion, while 36% (of 1583 entries) met the TOC/TN \uffe2\uff89\uffa4 3 criterion, while total compliance was 32% (of 1893 entries). When targeting the LF, total compliance increased noticeably, between 43 and 58% depending on DM range, indicating that LFs are better suited RENURE candidate fertilisers than unseparated digestate.
", "keywords": ["Agriculture and Food Sciences", "AMENDMENT PROPERTIES", "RENURE", "liquid fraction", "SEWAGE-SLUDGE", "NITROUS-OXIDE EMISSIONS", "ANAEROBIC CO-DIGESTION", "SAFEMANURE", "7. Clean energy", "NUTRIENT RECOVERY PROCESSES", "NUE", "USE EFFICIENCY", "BIOGAS PRODUCTION", "ORGANIC FRACTION", "S", "circular economy", "Agriculture", "04 agricultural and veterinary sciences", "6. Clean water", "Nitrates Directive", "NFRV", "MINERAL FERTILIZERS", "Earth and Environmental Sciences", "digestate", "manure", "CATTLE SLURRY", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "http://www.mdpi.com/2073-4395/11/7/1374/pdf"}, {"href": "https://doi.org/10.3390/agronomy11071374"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agronomy", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/agronomy11071374", "name": "item", "description": "10.3390/agronomy11071374", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/agronomy11071374"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-07-07T00:00:00Z"}}, {"id": "10.3390/agronomy12010182", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:20:48Z", "type": "Journal Article", "created": "2022-01-12", "title": "Evaluating the Fertilising Potential of Blended Recovered Nutrients in Horticultural Growing Medium on Viola x wittrockiana L.", "description": "Viola x wittrockiana L. is an ornamental plant in high demand in horticulture. It is becoming more critical for greenhouse growers to focus on sustainable production to enhance plant quality while reducing negative environmental impacts. Therefore, assessing the effect of recycled phosphorous (P) and nitrogen (N) sources on the growth of viola could become very useful for producers in terms of sustainability. This experiment analysed the optimal fertiliser composition to grow viola using recovered fertilisers in a greenhouse trial under controlled conditions. Well-rooted viola plugs were grown in a standard peat-based growing medium. Using recycled sources of P and N as struvite and potassium struvite, ammonium sulphate, and ammonium nitrate, 14 fertiliser blends were prepared, tested, and compared with the slow-release commercial fertiliser Osmocote. Plants treated with ammonium nitrate showed healthy growth and optimal plant N concentrations. In contrast, most blends using the recovered ammonium sulphate resulted in an unacceptable increase of ammonium concentrations in the growing medium. The combination of ammonium sulphate and potassium sulphate caused an increase in the electrical conductivity in the growing medium, negatively affecting plant growth. However, blend 13 containing struvite, ammonium sulphate and potassium struvite expressed the best chemical composition with non-significant differences in the biomass from the positive controls, as it reduced the amount of potassium sulphate needed. Our results indicate that fertiliser blends containing P as struvite, N as ammonium nitrate or reduced amount of ammonium sulphate, and K as potassium struvite can substitute the use of mineral fertiliser blends to grow ornamental plant species as viola.
", "keywords": ["Agriculture and Food Sciences", "nutrient recycling", "0301 basic medicine", "alternative fertilisers", "WASTE", "plant nutrition", "struvite", "PANSY", "12. Responsible consumption", "03 medical and health sciences", "PLANTS", "recovered nutrients; ornamental plants; greenhouse flowers; sustainable plant production; alternative fertilisers; plant nutrition; struvite; nutrient recycling", "ornamental plants", "recovered nutrients", "greenhouse flowers", "2. Zero hunger", "S", "Agriculture", "04 agricultural and veterinary sciences", "15. Life on land", "DIGESTATE", "sustainable plant production", "MINERAL FERTILIZERS", "GROWTH", "0401 agriculture", " forestry", " and fisheries", "info:eu-repo/classification/ddc/640", "Agronomy and Crop Science", "FORM"]}, "links": [{"href": "http://www.mdpi.com/2073-4395/12/1/182/pdf"}, {"href": "https://www.mdpi.com/2073-4395/12/1/182/pdf"}, {"href": "https://doi.org/10.3390/agronomy12010182"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agronomy", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/agronomy12010182", "name": "item", "description": "10.3390/agronomy12010182", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/agronomy12010182"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-01-12T00:00:00Z"}}, {"id": "10.3390/agronomy12020265", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:20:48Z", "type": "Journal Article", "created": "2022-01-21", "title": "Slurry Acidification as a Solution to Minimize Ammonia Emissions from the Combined Application of Animal Manure and Synthetic Fertilizer in No-Tillage", "description": "The combined application of manure/slurry and synthetic fertilizer (SF) might be a solution to decrease transport and application costs involving those by-products as well as enable access to them in regions where availability is low. Moreover, their joint application can potentially reduce environmental pollution, enlarge the manure benefits to more areas, and enhance the SF efficiency. However, such a strategy might result in increased ammonia emissions when applied to crop residues. Two experiments were implemented to assess ammonia emissions from stubble-covered soil fertilized with manure amended with SF. In Experiment 1 (E1), urea (U) and calcium ammonium nitrate (AN) were applied combined with dairy manure (MAN). In Experiment 2 (E2), urea was combined with acidified pig slurry (APS) and applied just after sowing (T0) or eight days later (T8). The combinations U + MAN and AN + MAN increased the ammonia emissions, while APS decreased the emissions from U, in APS + U combination, by more than 75%. Therefore, manure combined with SF applied on stubble-covered soil should not be recommended. T8 reduced ammonia emissions from U. APS enhanced the efficiency of U, being then an interesting strategy to mitigate ammonia emissions when applied on stubble-covered soil, as in no-tillage.
", "keywords": ["2. Zero hunger", "acidified slurry", "crop residues", "stubble-covered soil", "S", "acidified slurry; organic-mineral fertilizer; manure; conservation agriculture; crop residues; stubble-covered soil; urea; in-season fertilization; slurry sidedressing", "Agriculture", "urea", "04 agricultural and veterinary sciences", "15. Life on land", "7. Clean energy", "6. Clean water", "organic-mineral fertilizer", "12. Responsible consumption", "conservation agriculture", "13. Climate action", "manure", "0401 agriculture", " forestry", " and fisheries", "slurry sidedressing", "in-season fertilization"]}, "links": [{"href": "http://www.mdpi.com/2073-4395/12/2/265/pdf"}, {"href": "https://www.mdpi.com/2073-4395/12/2/265/pdf"}, {"href": "https://doi.org/10.3390/agronomy12020265"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agronomy", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/agronomy12020265", "name": "item", "description": "10.3390/agronomy12020265", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/agronomy12020265"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-01-20T00:00:00Z"}}, {"id": "10.5061/dryad.ffbg79d23", "type": "Feature", "geometry": null, "properties": {"license": "unspecified", "updated": "2026-05-25T16:21:28Z", "type": "Dataset", "created": "2024-01-08", "title": "An isotope study on Nitrogen and Phosphorus use efficiency and movement in soil in a mimicked vermicompost-based organo-mineral fertilizer", "description": "unspecifiedPot Experiment Setup To assess N and P uptake by Italian ryegrass, a pot experiment was carried out for 8 weeks. Vermicompost (VC), a 15N-labeled N solution (Nsol) and a 33P-labeled P solution (Psol) were used to fertilize the soil and create the different treatments. A commercial vermicompost of bovine manure produced in Northwestern Italy was used in this study (Fig. S1). The commercial vermicompost was air-dried and milled to <2 mm. The vermicompost was characterized using the official methods of the Regione-Piemonte (1998). The residual humidity content of the dry vermicompost was 432 g kg-1, the pH in a water suspension (1:10) was 9.9, the Corg value in dry matter was 198 g kg-1 DM , the total P was 9 g kg-1 DM , and the total N was 14.8 g kg-1 DM. Ammonium sulfate ((NH4)2SO4) and potassium phosphate (KH2PO4) were used to prepare separate aqueous solution of 80.3 \u00b5g N ml-1 and 28.5 \u00b5g P ml-1, respectively. The Nsol was prepared by dissolving 9.57 mg of (NH4)2SO4 and 9.53 mg of 10 atom% 15N((NH4)2SO4 into 50 ml of Milli-Q water, resulting in a N solution with 5.5 atom% 15N abundance. On the same day of sowing, the Psol was prepared by dissolving 625 mg of KH2PO4 into 50 ml of Milli-Q water, and labeled by adding carrier-free 33P orthophosphate (Hartmann Analytics) solution to reach a specific activity of 10.7 kBq mg-1 P. Although creating a granular or pelletized OMF would have been ideal for testing potential physical interactions between vermicompost and the mineral fertilizers, this effect was not addressed in this research because of the difficulties in producing and OMF labelled with a radioisotope P tracer. Therefore, the vermicompost and the fertilizer solutions were used to mimicking an OMF granule by mixing them together in the soil. Treatments included two mixtures of vermicompost with mineral fertilizers at a ratio between Corg \u2013 N \u2013 P205 ratio of 7.5 \u2013 20 \u2013 10 (OMF7.5C) and 15 \u2013 20 \u2013 10 (OMF15C). Controls included unfertilized soil (N0P0), soil fertilized with only mineral N (MFN), only mineral P (MFP), mineral N and P (MFNP), and vermicompost at the same rates as OMF7.5C (OF7.5C) and OMF15C (OF15C). With the Pmin fertilization (Fig. S2), soils from the pot experiment received an activity of 314 Bq g-1 soil. The soil for the experiment was collected from the experimental station of Tetto Frati of the University of Turin, in NW Italy (44\u00b0 53\u2032 N, 7\u00b0 41\u2032 E; elevation 245 m). Soil was collected from the first 0.2 m of the top layer of a plot managed with maize monoculture, regularly plowed and fertilized as the typical agronomic management of the area. The soil was sieved to 5 mm and air-dried for approximately four months prior to the start of the experiment. The soil chemical characteristics measured before the beginning of the experiment indicated a low content in both plant-available N and P. Before starting the pot experiment, the bulk soil was fertilized with nutrient solutions adding 300 mg K, 60 mg Ca, 50 mg Mg, 1 mg Zn, 0.1 mg Mo, 1 mg Fe, 1 mg B, 2 mg Mn, 2 mg Cu and 0.1 mg Co per kg-1 soil to avoid any possible complementary nutrient deficiency. After fertilization, the soil was humidified to 45 % of its water holding capacity (corresponding to 109 g per kg of dry soil) and pre-incubated during 10 days at 22 \u00b0C to boost soil microbial activity. After pre-incubation, the pots were filled with the equivalent of 1 kg of air-dried soil and fertilized according to treatments. For the fertilization, two holes of 2 cm of depth and 0.5 cm of diameter were made in each pot, and on day 0, each of them was fertilized. Immediately after fertilization, 0.75 g seeds of Italian ryegrass (Lolium multiflorum var. Gemini) were distributed uniformly over the soil and then covered with 100 g of pure sand. The pots were kept in a greenhouse at 24 and 20 \u00b0C, with 12 hours light, and 65% air humidity. Soils were irrigated daily based on weight loss. To satisfy the crop requirements, irrigation was increased to keep 60 % of field capacity during the first 2 weeks, and then up to 70 % of field capacity until the final harvest. The first harvest was made 4 weeks (Fig. S3) after sowing and a second harvest was made after 4 further weeks. The harvest consisted in cutting the whole biomass at approximately 1 cm above the soil surface. Each treatment had 4 replicates. Pots were completely randomized three times per week. Incubation Experiment Setup An incubation experiment was performed to assess the influence of the vermicompost on the nutrient availability and flow from the mineral fertilizers in the soil. Soil fertilizers used were the same as in the pot experiment, but no plants were sown. The treatments for the incubation were MFNP, OMF7.5C and OMF15C. The incubation set-up and soil sampling was adapted from Sica et al. (2023), and consisted in using plastic cylinders of 18 mm of height and 60 mm of diameter. Each experimental unit had two cylinders placed one above the another and was filled with 148.6 g of soil in total. The two cylinders were separated by a nylon net with 45 \u00b5m mesh size that allowed soil solution flow. The top cylinder was fertilized replicating vermicompost, Nsol, and Psol quantities and procedures as for one hole of the pot experiment. On the day of the Pmin fertilization, the Psol had a specific activity of 3.5 kBq mg-1 P.\u00a0 With the Pmin fertilization, soils from the incubation experiment received an activity of 313.5 Bq g-1 soil.\u00a0 The soil in cylinders was humidified to 70 % of field capacity. Experimental units were placed in a box covered with a plastic sheet that did not allow vapor and light flows and kept at the same temperature conditions as the pot experiment for 10 days. Each treatment had 6 experimental units and they were completely randomized. After the incubation, the soil from the top cylinder (topsoil) was collected entirely, while from the bottom cylinder additional soil was collected from the mesh to 6 mm depth (bottom soil). Soil from two randomly chosen experimental units was mixed to reach a higher amount of sample to be analyzed, thus leaving a total of 3 replicates per treatment. Measurements on Plants In the pot experiment, at each harvest, Italian ryegrass shoot biomass was cut and dried at 40 \u00b0C for 72 hours, and then weighted to calculate dry matter yield. Afterwards, all shoot biomass was milled in a rotational miller and stored until analysis. A chemical element analyzer (Vario Pyro cube, Elementar, Germany), coupled to a mass spectrometer (IsoPrime100 IRMS, Isoprime, United Kingdom) was used to analyze total C, total N and 15N/14N from shoot biomass. For determination of P concentrations in shoot tissues, 0.25 g of milled ryegrass shoot biomass were ashed at 450 \u00b0C during 100 min. Subsequently, ashes were dissolved in 3 ml of 15.6 M nitric acid and then the volume was brought up to 25 ml with Milli-Q water. Total P concentration in the extracts was analyzed by colorimetry with malachite green (Ohno & Zibilske, 1991). The 33P radioactivity in biomass was determined using a liquid scintillation counter (TRI CARB 2500 TR, Packard) by mixing 2 ml of extract or solution with 5 ml of a scintillation liquid (Ultima Gold AB, Packard). Values were corrected for quenching and for radioactive decay back to the day of pot fertilization. Measurements on Soil Soil samples of the incubation experiment were dried at 40\u00b0C for 3 days and then ball-milled and stored until analysis. Soil samples were analyzed for concentration of total N and 15N/14N ratio with the same method and instruments as for plant samples. The 15N enrichment of total soil N was then related to the 15N enrichment of the fertilizer and decreasing 15N enrichment of soil N interpreted as less fertilizer N having moved in the respective soil zone/layer (Frick et al., 2022). For determining P contained in soil, soil ashes were obtained similarly to plant biomass ashes. Soil ashes were dissolved into 50 ml of H2SO4 solution (0.5 M). Then, 5 to 10 ml of the solution was filtered with 0.2 \u03bcm syringe filters and stored at 4\u00b0C for 1 day until analysis of radioactivity. Values of 33P radioactivity in extracts were measured 32 days after fertilization following the same procedures as with biomass samples and corrected for radioactive decay by calculating back to day 0 of fertilization. The decrease of the specific activity of the soil P with distance from the fertilizer spot indicated decreasing presence of fertilizer P (as above explained for N). Statistical Analysis Both experiments had a completely randomized design. When testing for differences between treatments over the harvests, a repeated measures ANOVA was used. The incubation experiment was analyzed comparing treatments of each soil layer with a one-way ANOVA using treatment as factor. If significant differences between treatments were found a Tukey\u2019s HSD test was performed as a post hoc comparison. Some values were analyzed as the total production (sums or averages of both harvests, or both soil layers), in those cases data were analyzed by a one-way ANOVA using treatment as factor. All analyses were performed using the software R, version 4.0.5. Package multcompView was used to display post hoc results.", "keywords": ["vermicompost", "FOS: Agricultural sciences", "nutrient use efficiency", "double labeling", "organo-mineral fertilizer"], "contacts": [{"organization": "Sitzmann, Tomas Javier, Sica, Pietro, Zavattaro, Laura, Moretti, Barbara, Grignani, Carlo, Oberson, Astrid,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5061/dryad.ffbg79d23"}, {"rel": "self", "type": "application/geo+json", "title": "10.5061/dryad.ffbg79d23", "name": "item", "description": "10.5061/dryad.ffbg79d23", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5061/dryad.ffbg79d23"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2023-01-18T00:00:00Z"}}, {"id": "11370/a5fba259-dd61-43ac-8b8a-86b2d5fd6cef", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:24:48Z", "type": "Journal Article", "created": "2025-08-20", "title": "Regenerating productivity after soil fertility depletion in a 20-year cotton\u2013maize rotation in Benin", "description": "AbstractSoil degradation is a major challenge in Sub-Saharan Africa, where integrated soil fertility management has been promoted to restore productivity. A long-term experiment (1972\uffe2\uff80\uff931992) run in Benin consisted of two phases: a depletion phase (1972\uffe2\uff80\uff931980) with varying levels of mineral and organic fertilisation, and a regeneration phase (1981\uffe2\uff80\uff931992) where all plots received full fertilisation and organic matter additions. Soils were sampled at 0\uffe2\uff80\uff9320\uffc2\uffa0cm depth in 1973, 1974, 1982, and 1989 to assess fertility changes. Mineral fertilisation (N, P, K) and plant biomass management (crop residue retention and biomass additions) significantly influenced seed cotton and maize grain yields during the depletion phase. Soil organic carbon declined consistently in all treatments during depletion but remained stable during regeneration. The long-term effect was evident only in seed cotton yield during depletion. In contrast, due to high variability, maize grain yield showed no consistent trend. The combined use of organic resources and mineral fertilisers helped maintain crop productivity but led to declining soil chemical properties in this Ferralsol. The analysis of this outdated yet unpublished dataset shed light on how long-term soil depletion effects persist over time, even when soil fertility management is restored, indicating a sort of \uffe2\uff80\uff98soil memory\uffe2\uff80\uff99. The persistence of these effect suggests that regenerative interventions must begin before critical thresholds of degradation are crossed. Future research should focus on alternative measures to restore/maintain soil fertility not evaluated in this experiment, such as conservation tillage or legume integration, to provide long-term benefits for smallholder farmers facing soil fertility challenges.