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The vegetation in the Arabian Peninsula experiences drought, heat, soil salinity, and low fertility, mainly due to low phosphorus (P) availability. The beneficial mycorrhizal symbiosis between plants and arbuscular mycorrhizal fungi (AMF) is a key factor supporting plant growth under such environmental conditions. Therefore, AMF strains isolated from these soils might be useful as biotechnological tools for agriculture and revegetation practices in the region. Here we present a pioneering program to isolate, identify, and apply AMF isolated from rhizosphere soils of agricultural and natural habitats, namely date palm plantations and five native desert plants, respectively in the Southern Arabian Peninsula. We established taxonomically unique AMF species as single-spore cultures as part of an expanding collection of AMF strains adapted to arid ecosystems. Preliminary experiments were conducted to evaluate the abilities of these AMF strains to promote seedling growth of a main crop Phoenix dactylifera L. and a common plant Prosopis cineraria L. (Druce) in the Arabian Peninsula. The results showed that inoculation with certain AMF species enhanced the growth of both plants, highlighting the potential of these fungi as part of sustainable land use practices in this region.

For environmental conservation, peat-based growing media are being phased-out in many countries. Peat-free alternatives need to be developed, preferably from local biomass ingredients. This paper describes the performance of peat-free substrates containing olive branch pruning materials in comparison with commercial growing media controls for olive saplings grown during April-October 2020 at the Olive Research Institute (ORI) in Turkey. The trial was conducted using a randomized plot design with 4 replications and 4 treatments: 1) (COMP) compost made of locally available plant materials with 70% olive prunings (100%, v v-1; 2) (FIBER) mixture of chipped and extruded olive prunings (50% chipped + 50% extruded, v v-1); 3) (SAND) a commercial mixture(sand 90% + vermiculite 10%, v v-1) (control); and 4) (PEAT+) a commercial mixture (peat 40% + coco coir 40% + perlite20%, v v-1) (control). The vegetative growth parameters and weed status (density and coverage) were recorded and root fungal diseases commonly found in Turkey were analyzed. After the first six months of growth, there were statistically significant differences between the treatments (p≤0.05); COMP and PEAT+ were comparable and produced the largest plants with 100% survival rate. 98% of plants survived in SAND, and 81% in FIBER.FIBER, which was the only treatment with no weed growth, had about 30% reduced growth as compared to SAND, which had 90 and 78% growth compared with PEAT+ and COMP. Still, it was remarkable that it was possible to grow olive saplings in treated olive prunings. It is very promising that a peat-free growing media like COMP performed as well as the commercial growing media with 40% peat. During the extrusion of olive material, the temperature rose to ca. 120°C and during composting the COMP reached 65-70°C; temperatures at which the materials are expected to be effectively sanatised from any fungal diseases.

Manure treatment such as anaerobic digestion and solid-liquid separation has shown a potential to abate greenhouse gas (GHG) emissions, but few studies have considered GHG emissions from both storage and field application regarding crop yield. In this study, four different organic fertilizers were studied: untreated cattle manure (CA); digestate of cattle manure anaerobically co-digested with grass-clover (DD); a liquid fraction from the separation of DD (LF); and a liquid fraction derived from a biogas desulfurization biofilter enriched with sulfur and ammonium (NS). The CH4, N2O and NH3 emissions during storage of CA, DD and LF between August and November 2020 (11 weeks) were quantified. Storage continued until April 2021 when these materials, as well as the NS fertilizer and a mineral NKS fertilizer, were applied at a rate of 100 kg total N ha−1 to spring barley. N2O emissions and soil mineral N content were monitored during the growing season. Overall, CH4 emissions during storage were the main source of GHG emissions independent of treatments, accounting for 85 %, 40 % and 11 % of total GHG emissions (based on field application of 100 kg ha−1 total N) from treatments CA, DD and LF, respectively. Anaerobic digestion and separation significantly reduced CH4 emissions during storage due to the diminished content of degradable organic matter available for methanogens. The N2O emissions from treatments CA, DD, and LF during storage were not significantly different. Treatments DD and LF emitted more NH3 than CA during storage, presumably because of higher pH and ammonium content. In the field experiment, the dilute solution of NS emitted the most N2O, while emissions from treatments CA, DD and LF were comparable. Yield-scaled GHG emissions for treatments CA, DD, LF and NS during both periods of storage and field were 44.4, 17.1, 8.5 and 24.3 kg CO2 eq hkg−1 grain yield, respectively. Anaerobic digestion with or without separation were thus effective strategies for the mitigation of GHG emissions from cattle manure in this study. Yields and nitrogen use efficiencies of the processed manure materials were not significantly different from those observed with the same N application rate as inorganic fertilizer, and hence anaerobic digestion with or without separation were promising GHG mitigation strategies.

The decomposition of plant organic materials in the soil during the non-vegetation period in a cool temperate climate is associated with nutrient loss and asynchrony in nutrient supply for subsequent crops. Therefore, it is important to select sustainable management tools to regulate the decomposition rate of organic material during the non-vegetation period. The aim of the present study was to assess the influence of soil type (loam vs. clay loam), green manuring (wheat straw vs. wheat straw + red clover), and incorporation depth of organic materials (4–7 vs. 14–17 cm) on mass loss, decomposition rate and stabilization of standardised organic material in the organically managed arable soils. A Tea Bag Index method was used in the field experiments with standardised organic plant materials of green and rooibos tea. In addition, litter-bags of locally grown red clover were investigated. The findings of this study suggested that of the three management factors investigated soil type had a significant and longest effect. The mass loss and decomposition rate of the standardised organic materials were significantly (P < 0.5) higher and stabilization significantly lower in the loam soil than in the clay loam soil. During the non-vegetation period, green tea lost 46.3% of its initial mass, rooibos tea lost 19.7% and red clover lost 66%. The study showed that decomposition of fast-decomposing materials could be slowed down during the non-vegetation period by choosing soils with a higher clay content, shallow organic material incorporation depth and manuring soil with N-rich plant residues.

This paper reviews relevant knowledge about the production and uses of fertilizers from fish and fish waste (FW) that may be applicable for certified organic farming, with a focus on crop and horticultural plants. Fish industries generate a substantial amount of FW. Depending on the level of processing or type of fish, 30–70% of the original fish is FW. Circular economy and organic farming concepts were used to evaluate the potential of production of fertilizers from captured fish. Fertilizers produced from captured fish promote the recycling of nutrients from the sea and back to terrestrial environments. Nutritional composition of FW is assessed to determine the potential to supply plant nutrients such as nitrogen, or a combination of nitrogen and phosphorous, or to enrich a compost. Methods used in processing of FW to produce fish- emulsion, fish hydrolysate/fish silage, fish-compost and digestate from anaerobic digestion/co-digestion are presented. Using information about commercially available fish-based fertilizers listed by the Organic Materials Review Institute (OMRI), we present a scenario for establishing fish/ FW-based fertilizers industry and research in Europe. With Norway’s 9th position among top ten global capture producers and focus in Norway on developing organic farming, we brief how FW is currently utilized and regulated, and discuss its availability for possible production of FW-based organic fertilizers. The amount of FW available in Norway for production of fertilizers may facilitate the establishment of an industrial product that can replace the currently common use of dried poultry manure from conventional farming in organic farming.

Date palm (Phoenix dactylifera L.) is an important crop in arid zones and plays significant ecological and socio-economic roles. During the last decades, date palm groves were subjected to degradation due to extensive soil exploitation and low soil fertility. The use of biological techniques is essential to improve date palm development. The present work aims at assessing the effect of two different doses of compost (5% and 20%) and inoculation with the arbuscular mycorrhizal fungus (AMF) Rhizoglomus irregulare on growth and development of date palm seedlings. The treatments comprised control and application of 5 and 20% of compost with R. irregulare individually or in combination. Growth, physiological, histological, and mycorrhization traits were assessed. Obtained results showed that compost applied at a low dose (5%) alone or in combination with the AMF stimulated root length, leaf area, root dry weight, nitrogen, phosphorus and potassium contents, stomatal conductance and chlorophyll fluorescence and increased the number of sclerenchyma fibers, the number of vascular bundles, root diameter, and lignification of the endodermis of date palm seedlings compared to control. Compost at low doses combined or not with AMF can successfully be applied as biofertilizers for improving the growth and development of date palm.

Agricultural management of soils has led to severe losses of soil organic matter (SOM), accompanied by an increased release of CO2 into the atmosphere and a reduction of soil fertility. Especially under the aspect of global warming and the increasing demand for food, there is a need for sustainable management options increasing soil organic carbon (SOC) storage in agricultural soils, but knowledge gaps exist regarding C persistence in, and its transfer between functional SOC pools, within different farming systems. Here we report on impacts of different farming systems on the temporal dynamics of SOM fractions within the DOK long-term trial (Switzerland), from 1982 to 2017. A purely minerally (CONMIN), a minerally and organically (CONFYM), and a purely organically fertilized farming system (BIODYN) were compared with an unfertilized control (NOFERT). We separated archived soils from the Haplic Luvisol (0–20 cm depth) into particulate (POM) and mineral-associated OM (MAOM) fractions, via physical fractionation, and analyzed the chemical composition of selected fractions via solid-state 13C CPMAS-NMR spectroscopy. We demonstrate that under none of the analyzed farming systems, additional SOC was sequestered in the clay-sized MAOM fraction (

Wheat is a staple food crop and a major source of both the essential micronutrient zinc (Zn) and the toxic heavy metal cadmium (Cd) for humans. Since Zn and Cd are chemically similar, increasing Zn concentrations in wheat grains (biofortification), while preventing Cd accumulation, is an agronomic challenge. We used two Swiss agricultural long-term field trials, the “Dynamic-Organic-Conventional System Comparison Trial” (DOK) and the “Zurich Organic Fertilization Experiment” (ZOFE), to investigate the impact of long-term organic, mineral and combined fertilizer inputs on total and phytoavailable concentrations of soil Zn and Cd and their accumulation in winter wheat (Triticum aestivum L.). “Diffusive gradients in thin films” (DGT) and diethylene-triamine-pentaacetic acid (DTPA) extraction were used as proxies for plant available soil metals. Compared to unfertilized controls, long-term organic fertilization with composted manure or green waste compost led to higher soil organic carbon, cation exchange capacity and pH, while DGT-available Zn and Cd concentrations were reduced. The DGT method was a strong predictor of shoot and grain Cd, but not Zn concentrations. Shoot and grain Zn concentrations correlated with DTPA-extractable and total soil Zn concentrations in the ZOFE, but not the DOK trial. Long-term compost fertilization led to lower accumulation of Cd in wheat grains, but did not affect grain Zn. Therefore, Zn/Cd ratios in the grains increased. High Zn and Cd inputs with organic fertilizers and high Cd inputs with phosphate fertilizers led to positive Zn and Cd mass balances when taking into account atmospheric deposition and fertilizer inputs. On the other hand, mineral fertilization led to the depletion of soil Zn due to higher yields and thus higher Zn exports than under organic management. The study supports the use of organic fertilizers for reducing Cd concentrations of wheat grains in the long-term, given that the quality of the fertilizers is guaranteed., info:eu-repo/semantics/published

Tento informační list shrnuje nejnovější výsledky výzkumu o účinnosti a používání biohnojiv.

Arbuscular mycorrhizal fungi (AMF) have been frequently reported as effective tools for alleviating environmental stresses and promoting plant growth and yield. In this study, we aimed to isolate, culture, and identify molecular and morphological AMF species associated with date palms and spontaneous plants present at eight sites in the arid agroecosystem of the Drˆaa-Tafilalet oasis of Morocco. We tested the capacity of AMF to colonize micropropagated date palm seedlings at their first acclimatization stage. Soil and root samples were collected to propagate indigenous AMF strains using trap culture techniques under greenhouse conditions and, at the same time, their root colonization potential was evaluated. We used freshly propagated spores to establish a collection of single spore-derived cultures. Morphological, microscopic, and molecular approaches were adopted to quantify AMF communities in the roots and rhizosphere and identify the recovered AMF species present at the eight sites. In an inoculation experiment, a micropropagated date palm was inoculated with a consortium of four cultured AMF strains, alone or in combination with synthetic fertilizer or compost. Our results showed that after two cycles of trap culturing, the frequency and intensity of AMF colonizing host plant roots significantly increased, exceeding 91% and 50%, respectively. Using three trap plant species and favorable growing conditions helped increase root colonization rates and AMF proliferation. AMF propagation resulted in the cultivation of 13 AMF strains. Molecular and morphological analyses revealed six different AMF species within our cultures: Pervetustus simplex, Claroideoglomus etunicatum, Albahypha drummondii, Septoglomus xanthium, Funneliformis mosseae, and Rhizoglomus irregulare. Results of the inoculation experiment revealed that root colonization was higher in treatments augmented with synthetic fertilizers than those supplemented with compost with 84.4% as against 46.7% and 26.1% as against 12.3%, respectively, for colonization frequency and intensity. In contrast, shoot length and stem diameter of date palms were significantly higher in treatments augmented with compost and AMF than that with synthetic fertilizers. Synthetic fertilizers might have been partially immobilized directly after application, limiting availability and resulting in lower growth performance of date palms. These findings indicated that date palm groves are a niche for efficient indigenous AMF strains that can colonize and enhance date palm growth at the early stages.

Demands upon the sustainability of farming are increasing in step with climate change and diversity loss. Organic farming offers a viable approach. To further improve organic management, three strategies with potential to enhance soil quality are being tested in a long-term trial since 2002 on a clay loam in temperate Switzerland: reduced tillage vs. ploughing, solid vs. liquid manures and biodynamic preparations. A synthesis of 15 years reveals an increase in topsoil organic carbon (SOC, +25%), microbial biomass (+32%) and activity (+34%) and a shift in microbial communities with conversion from ploughing to reduced tillage. Soils under reduced tillage are more stratified in SOC and nutrients. Additional application of composted manure has increased SOC by 6% compared to pure slurry application, with little impact on soil microbes. Biodynamic preparations have had a minor impact on soil quality. Fertilisation and biodynamic preparations did not affect yields. Both higher and lower yields were harvested in the reduced tillage system in relation to ploughing. The main yield determinants were N supply and higher weed infestation under reduced tillage. Continuously reduced tillage in organic farming has been proven to enhance soil quality at this site, while also presenting more challenges in management.

Leguminous green manure crops are important for accumulating nitrogen by means of biological nitrogen fixation and for building up soil fertility in organic arable cropping systems. Whole-year green manure crops are also known to deplete the soil weed seed bank, e.g. by decaying and predation, but there is uncertainty about the magnitude of the legacy effect after termination of the green manure crop. This study sampled soil for weed seed bank assessment upon termination of a two-year leguminous green manure crop and then one, two and three years afterwards. The samples were taken from two five-year crop rotations (2011–2015) in a long-term organic crop rotation experiment in Denmark. One rotation (O2) had a two-year green manure crop followed by three years of annual cash crops, and the other rotation (O4) consisted only of annual cash crops, with four crop sequences in both rotations represented every year. In general, the weed seed bank of rotation O2 was 54 % lower than O4, with 5475 seeds m−2 versus 11,967 seeds m−2. Similarly the aboveground amount of weed biomass in O2 was lower than in O4 over the course of the five years. The legacy effect of the green manure crop showed a negative exponential rise in weed seed numbers with the increase in years after termination of the green manure crop. A biennial leguminous green manure crop can mitigate weed problems in organic annual crops. This effect adds to the benefits of including nitrogen fixing leys in crop rotations with limited access to animal manures.

Aims: To assess the effect of organic waste and their formulations on the development of the black soldier fly larvae. Study Design: The experiment used one time feeding (lump feeding) of feedstocks obtained from organic market waste fractions and their combinations. The arrangement of composting containers followed a Randomized Complete Block Design (RCBD), replicated three times. Place and Duration of Study: The study took 3 months and was conducted at the BSF laboratory of the Soil and Environmental Science Research Centre, Biotechnology and Nuclear Agriculture Research Institute of the Ghana Atomic Energy Commission in Accra, Ghana, West Africa. Methodology: Two hundred and forty (240) hand counted 5 day old BSF larvae were inoculated onto 2 kg each of organic market waste fractions and their combinations in 60 L plastic containers covered with a mesh. Equal quantities of the above feedstock without larvae served as control. The arrangement of the containers followed a Randomized Complete Block Design (RCBD), replicated three times. Moisture content, larval growth parameters, temperature, relative humidity, prepupal development were recorded. Results: Whiles moisture contents of most of the feedstock decreased gradually over the trial period, that of fruit waste only, fruit waste + corn husk and fruit waste + vegetable waste increased with time and was higher at the end of the trial than at the beginning. Composting temperature in all the feed stocks never reached the thermophilic stage and was between 29 – 38°C. The lowest temperature of 28.88°C was recorded in the mixture of vegetable waste and fruit waste whiles the highest, 37.55°C was recorded in the mixture of corn husk and uncooked food waste compost. Composting humidity ranged between 59 and 87% with significant differences being observed across treatments on days 0, 10, 15, 20 and 25. Larvae reared on a mixture of all the feedstock was significantly the heaviest (176.66 mg). Significant differences were observed in larval length and those fed with a mixture of fruit waste and uncooked food waste were the longest (17.66 mm). A highly significant number of eclosed adults, number of females and the number of egg clutches were observed among treatments. Conclusions: Vegetable waste only, fruit waste only and a combination of vegetable waste + uncooked food waste; fruit waste +uncooked food waste; and a combination of all the wastes were the most preferred organic waste as they produced the optimum larval characteristics. The composting bins should be fitted with an outlet for leachates from the compost to drain out to avoid increase in compost moisture which will create anaerobic conditions that might delay compost maturity.

Aims Belowground legume nitrogen (N) composed of roots and rhizodeposition is an important N input to soils, but published data of belowground N vary broadly, probably due to extrapolation from short-term experiments and dissimilar growing conditions. We quantified belowground N inputs of red clover (Trifolium pratense L.) during two consecutive years in a clover-grass sward along a soil nutrient availability gradient. Methods We established a red clover-perennial ryegrass (Lolium perenne L.) model sward in microplots located in field plots of the DOK experiment, which has a 33-year history of organic and conventional cropping, resulting in a soil nutrient availability gradient. Four treatments were examined: the zero fertilisation control, bio-organic with half and full dose manure application, and the conventional system with mineral fertilisation at full dose. We studied the development of clover aboveground and belowground N using multiple pulse 15N urea leaf labelling. Results Belowground clover N increased over time and with rising nutrient availability and was proportional to aboveground clover N at all times. Belowground clover N amounted to 40% of aboveground clover N during two consecutive years, irrespective of the nutrient availability status. Belowground clover N development was initially dominated by fast root growth, followed by enhanced root turnover during the second year. Potassium availability limited clover growth and total N accumulation in treatments with low nutrient availability. Conclusions Belowground red clover N inputs could be estimated from aboveground N by a constant factor of 0.4, regardless of the nutrient availability and cultivation time. Root turnover led to a distinct absolute increase of N rhizodeposition over time. Hence, N rhizodeposition, with an 80% share of belowground N, was the predominant N pool at the end of the second year.

Organic greenhouse vegetable production is characterized by very high nutrient demands within short growing periods and high nutrient exports via products sold. Therefore, meeting crop nutrient demands and maintaining long-term sustainability in these systems is highly challenging. To gain insight in current practices this study assessed fertilization strategies and nutrient flows of ten organic horticultural farms (22 greenhouses and polytunnels) in Southwest Germany belonging to the two organic farming associations Bioland and Demeter (biodynamic) for a cropping period of three years. Soil samples were taken to analyze plant available phosphorus, potassium, soil organic carbon, pH and salinity. Crop rotations in the greenhouses were very diverse, though focused on tomatoes. Depending on association membership, fertilization was based either on the use of solid animal manures (26.1 Mg ha−1 a−1) and composts (7.9 Mg ha−1 a−1) for the biodynamic Demeter farms or on commercial complementary fertilizers on the Bioland farms (e.g. keratin products, food industry waste products). All farms showed strong imbalances in their nutrient flows with high average surpluses for all nutrients (197 kg ha−1 a−1 for nitrogen, 47.9 kg ha−1 a−1 for phosphorus, 119 kg ha−1 a−1 for sulfur) except potassium with an average deficit of 143 kg ha−1 a−1 and low nitrogen use efficiencies. In addition, a risk for increased soil alkalinity and salinity existed and concentrations of plant available phosphorus in the soil were very high (average 332 mg phosphorus kg−1). The results show that today’s fertilization strategies for organic greenhouses are not sustainable, which calls for a thorough revision of the core ideas on soil fertility in the organic horticultural sector.

Vigorous seedlings are an important base for vegetable production. Beside the availability of appropriate amounts of nutrients, the health of seedlings is decisive. Soil-borne diseases are a challenging problem in organic seedling production. Here, we present results on the development of disease-suppressive growing media. Three aspects were examined: (i) use of different components of growing media (peat, coconut fiber, wood fiber, compost), (ii) influence of selected organic nitrogen fertilizers and (iii) use of different microorganisms (including commercial biocontrol agents (BCA)). Three plant-pathogen systems were used in this study: cucumber-Pythium ultimum, cress-Pythium ultimum and basil-Rhizoctonia solani. Green waste compost showed a good capability to protect cress against P. ultimum. This effect was improved by using a chitin-containing N-fertilizer. However, an inappropriate storage of the compost diminished its efficacy. In contrast to coconut fibers, wood fibers showed a suppressive activity against P. ultimum when used as partial substitutes of peat. None of five tested commercial BCAs could improve the suppressiveness of the substrates against P. ultimum. However, one of newly tested strains of Trichoderma sp. was very suppressive against P. ultimum. The tested growing media showed only small differences in suppressiveness against R. solani on basil. In contrast, two of the new strains of Trichoderma sp., which were intermediately active against P. ultimum, could efficiently protect basil against R. solani. At the moment, we test combinations of different Trichoderma strains, compost, different types of peat and peat substitutes. The aim is to determine whether it is feasible to manufacture growing media which allow the production of healthy and robust seedlings also in the presence of high levels of pathogens.

Soil-borne diseases such as damping-off caused by Pythium sp. are responsible for high yield losses in organic vegetable production and are difficult to control. Compost amendments have been shown to improve in many cases survival and growth of plants in soils infested with soil-borne diseases. Yet, not all composts are disease suppressive and suppressiveness of composts can be pathogen-specific. Cress (Lepidium sativum L.) was grown in a standard peat substrate amended either with coco fiber (conducive control) or with composts differing in their suppressiveness towards Pythium ultimum. Bacteria were isolated from the rhizoplane and the most abundant species identified by MALDI-TOF MS. The bacterial composition in the rhizoplane of plants grown in non-suppressive substrates and in the suppressive compost was essentially different. Aeromonas media was the main species isolated from the rhizoplane of plants grown in a suppressive compost, whereas Enterobacter cloacae was the dominating species in the less suppressive compost and in the conducive control. A. media was then added to all substrates to evaluate its role in disease suppression. Addition of A. media improved suppressiveness against P. ultimum in all substrates. The effect was most pronounced in the substrate amended with the compost with low suppressiveness, resulting in levels of suppressiveness comparable to the highly suppressive compost. We conclude that presence of A. media in composts can contribute to disease suppression and might provide a useful marker for qualitative analysis of composts.

In temperate regions, legume-based green manures are a key element of organic rotations. However, specialized farms lack sufficient mobile organic fertilizers. To gain a better understanding of the N flows and the nitrogen (N) and phosphorus (P) fertilizer value of different clover-grass-based fertilizers (biogas digestate, compost, silage and fresh clover-grass obtained from clover-grass ley biomass), we assessed their fertilizer value. Nitrogen and P offtake by the ryegrass was used to assess the short-term effects. The data were completed using model calculations to assess the field-to-field N-transfer efficiencies and the overall N-transfer efficiencies. The greatest plant N offtake was achieved with digestates (64%) and the lowest from the compost (6%) and solid farmyard manure (14%). The mineralization rate was positively related to the NH4 +–N/total N ratio (P

Inoculation with phosphorus (P) solubilizing bacteria is being proposed to increase P availability for plants by mineralization and solubilization of non-available soil and fertilizer P. Solubilization of inorganic P compounds by bacterial strains has repeatedly been shown on agar plates and in liquid media. However, the effects of inoculation on P availability to plants growing in soils, either in pot or field studies, are inconsistent and do not allow to separate between direct effects on P availability and indirect effects such as improved plant health. This differentiation could be achieved using 33P isotopic labeling. We applied the 33P isotopic dilution method in a pot and in an incubation experiment to study gross P fluxes in a calcareous soil inoculated with the P solubilizing bacteria Pseudomonas protegens CHA0. We hypothesized that the inoculant dilutes the specific activity (33P/31P) in the soil solution or in the plant shoots because of P solubilization beyond the P mobilization by the endogenous microbial biomass. To this end, we conducted a plant growth experiment with Lolium multiflorum var. Gemini and an incubation experiment. In both experiments, the soil was amended or not with a calcium P rich sewage sludge ash, and both treatments were conducted with and without inoculation. The inoculant was able to solubilize P from sewage sludge ash under controlled conditions in liquid media. However, it did not enhance P release from soil or from sewage sludge ash in the incubated soil. Inoculation of the soil reduced organic P mineralization by the soil microbial biomass, which was supported by a simultaneous decrease in soil respiration. Thus, any inorganic P solubilized by the inoculant might have been offset by less basal organic P mineralization. Increased P uptake of inoculated Lolium multiflorum at first harvest was attributed to an indirect effect, since the specific activity in shoots of inoculated Lolium multiflorum was not decreased. Although sewage sludge ash contained very little water-soluble P, an increase in P availability following sewage sludge ash addition could be shown using 33P isotopic dilution, while biological processes remained unchanged. While in this study, the inoculant did not increase P availability, the approach presented here can give insight into the mechanisms underlying beneficial effects of inoculants.

Organic farming systems need to replace nutrients exported via farm products, especially phosphorus (P) which may otherwise become depleted in soil in the long term. In Europe, EU regulations for organic production are shaping the farming systems with respect to inputs of nutrients. Permitted off-farm P sources include conventional animal manure, composted or anaerobically digested organic residues, rock phosphate, and some animal residues such as meat and bone meal. The recent proposed revision of EU regulations for organic production (2014) puts less emphasis on closing nutrient cycles and instead aims at minimizing off-farm inputs, to reduce the risk of importing contaminants. This development, which has received little attention from the organic sector so far, is explained here. The paper further explores the regulatory conditions that govern the P supply to organic agriculture in six European countries: Austria, Denmark, Germany, Great Britain, Norway, and Switzerland. Organic farmers are subject to substantial variation in standards arising from the interpretation of EU regulations into national laws, restrictions imposed by private actors such as retailers, and private standards which may be stricter than EU regulations. In several countries, the majority of organic farmers are certified by private, stricter standards. We propose that EU regulations and private standards for organic production should not limit the use of recycled fertilizers in organic farming systems, as long as means are taken to ensure the quality and safety of these inputs. Awareness of the need to close nutrient cycles may contribute to adapting regulations and private standards to support recycling of nutrients from society to organic agriculture. A better definition of the term “natural substance” in organic regulations is required.

Phosphorus (P) is an essential element for all living organisms. At the current rate of extraction, global reserves of mineable deposits will be exhausted within the next few centuries. This publication aims to summarize the current knowledge on P recycling for organic farming. The evaluation of recycled P fertilizers (RPFs) includes (i) a chemical characterization, (ii) assessment of their plant P availability and added effects in the soil, (iii) life cycle assessments, (iv) a risk assessment of their long-term impacts on soil pollution, and (v) the compilation of other environmental impacts of different treatment approaches to produce RPFs. The highest nutrient recovery rates for P are achieved by rather simple process approaches of P recycling, while more sophisticated approaches often result in lower P recovery rates (e.g., chemical approaches for P precipitation), lower plant P availability in the final product (e.g., most thermal approaches), and losses of organic matter and nutrients like nitrogen and sulfur (e.g., thermal approaches). The plant P availability of many RPFs is higher than that of phosphate rock. Each P recycling approach has strengths and weaknesses. We conclude that any decision not to use a potential recycled P source or to introduce sophisticated treatments may have consequences compromising the ability of future generations to meet their needs. Nevertheless, we need to minimize risks for current and future generations caused by contamination linked to fertilization. Therefore, any management of nutrient recycling requires navigation between constraints. The challenge for the organic agriculture sector is to assess RPFs using a balanced approach that compromises neither the principle of ecology nor the principle of care.

Zinc (Zn) deficiency in human populations depending on cereals as a main source of Zn is a global malnutrition problem. In this field study, we investigated the potential of green manure application to increase soil Zn availability and wheat grain Zn concentrations (biofortification) on a Luvisol with different long-term fertilizer management. We also studied cadmium (Cd), as wheat is a major contributor of this undesired non-essential element to human diets. Clover (Trifolium alexandrinum L.), mustard (Sinapis alba L.) or no green manure was grown on field plots which had been managed with farmyard manure or mineral fertilizers for 65 years in Switzerland. After green manure incorporation into the soil, spring wheat (Triticum aestivum L.) was grown on all plots. The “diffusive gradients in thin films” (DGT) method and DTPA extraction were used to compare soil Zn and Cd availability among the treatments. In contrast to mustard, clover increased soil mineral nitrogen concentrations and wheat biomass; however, neither increased grain Zn concentrations. DGT-available Zn and Cd increased temporarily after both farmyard manure and mineral nitrogen fertilizer application. Higher DTPA-extractable soil Zn and Cd, lower wheat grain yields, but higher grain Zn concentrations were obtained with farmyard manure compared to mineral fertilizers, independent of the green manure treatment. Farmyard manure added Zn, Cd and organic matter that increased the soil binding capacity for Zn and Cd. The decomposition of clover residues caused higher wheat grain yields, but only marginally lower grain Zn concentrations. The absence of a stronger dilution of grain Zn was probably due to organic acid and nitrogen release from decomposing clover, which facilitated Zn uptake by wheat. The study revealed that both long- and short-term field management with organic matter alters soil Zn and Cd concentrations but that the long-term effects dominate their uptake by wheat, in Zn sufficient soil.

BackgroundAgricultural production is challenged by the limitation of non-renewable resources. Alternative fertilizers are promoted but they often have a lower availability of key macronutrients, especially phosphorus (P). Biological inoculants, the so-called bio-effectors (BEs), may be combined with these fertilizers to improve the nutrient use efficiency.MethodsThe goal of this study was to assess the potential of three BEs in combination with alternative fertilizers (e.g. composted manure, biogas digestate, green compost) to promote plant growth and nutrient uptake in soils typical for various European regions. Pot experiments were conducted in Czech Republic, Denmark, Germany, Italy, and Switzerland where the same variety of maize was grown in local soils deficient in P in combination with alternative fertilizers and the same set of BEs (Trichoderma, Pseudomonas, and Bacillus strains). Common guidelines for pot experiment implementation and performance were developed to allow data comparison, and soils were analyzed by the same laboratory.ResultsEfficiency of BEs to improve maize growth and nutrient uptake differed strongly according to soil properties and fertilizer combined. Promising results were mostly obtained with BEs in combination with organic fertilizers such as composted animal manures, fresh digestate of organic wastes, and sewage sludge. In only one experiment, the nutrient use efficiency of mineral recycling fertilizers was improved by BE inoculation.ConclusionsThese BE effects are to a large extent due to improved root growth and P mobilization via accelerated mineralization., info:eu-repo/semantics/published

The aim of the study was to establish a diagnostic tool to narrow down the causes for pea yield depressions. A differential two-level diagnostic test system was established under controlled conditions usingpeas (Pisum sativum L.) as test plants. Soils from 22 organically managed sites with unexplained moderate to high pea yield losses were tested in level 1 diagnostics (y-irradiation to eliminate potentiallyharmful organisms, nutrient additions to compensate for potential nutrient deficiencies or activated charcoal amendment to bind and thereby to immobilize potentially phytotoxic compounds). Results showedthat organisms harmful to the test plant were the primary cause of limited germination and growth inmost of the sampled soils, whereas a positive effect of nutrient addition was rarely found and toxinswere not involved. Level 2 diagnostics (pesticides targeting ascomycetes, oomycetes, Rhizoctonia spp.,nematodes) further narrowed down the organisms involved in yield depressions. Oomycetes were identified as the primary reason for limited germination rates, and, in some soils, also for limited growth ofestablished seedlings. In other soils, a multitude rather than a single group of pathogens was involved inlimited growth. Plantpathogenic nematodes were never found to be limiting for crop growth parameters. Harmful effects of pesticides were found in several soils, hinting at an important role of beneficialsoil organisms in the suppression of pathogens causing yield depression in legumes. The bioassay used inthe present study was robust and could thus serve as a low-cost tool for agricultural advisors and farm-ers to predict the risk of yield losses in legumes and to narrow down causes, helping them to develop appropriate strategies.

Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations in Denmark (12 years in total). The experimental treatments were: (i) crop rotation, (ii) catch crop and (iii) animal manure. Nitrate leaching was estimated from measured soil nitrate concentration in ceramic suction cells and modelled drainage. There were significant effects on annual N leaching of location (coarse sand > loamy sand > sandy loam) and catch crops (without > with). Including a grass-clover green manure on 25% of the area did not increase N leaching compared with crop rotations without green manure. Also the application of animal manure did not influence N leaching, probably because even in the manured treatments the application rate was lower than crop demand. The results identify management of crop and soil during autumn as the main determinant of N leaching. Nitrate leaching was lowest for a catch crop soil cover during autumn and winter (avg. 20 kg N ha−1), a soil cover of weeds/volunteers had on avg. 30 kg N ha−1, and the largest N leaching losses were found after stubble cultivation (avg. 55 kg N ha−1). The N leaching losses increased with increasing number of autumn soil cultivations

Urine deposition by grazing livestock causes an immediate increase in nitrous oxide (N2O) emissions, but the responsible mechanisms are not well understood. A nitrogen-15 (15N) labelling study was conducted in an organic grass-clover sward to examine the initial effect of urine on the rates and N2O loss ratio of nitrification (i.e. moles of N2O-N produced per moles of nitrate produced) and denitrification (i.e. moles of N2O produced per moles of N2O + N2 produced). The effect of artificial urine (52.9 g N m-2) and ammonium solution (52.9 g N m-2) was examined in separate experiments at 45 and 35% water-filled pore space (WFPS), respectively, and in each experiment a water control was included. The N2O loss derived from nitrification or denitrification was determined in the field immediately after application of 15N-labelled solutions. During the next 24 h, gross nitrification rates were measured in the field, whereas the denitrification rates were measured in soil cores in the laboratory. Compared with the water control, urine application increased the N2O emission from 3.9 to 42.3 μg N2O-N m-2 h-1, whereas application of ammonium increased the emission from 0.9 to 6.1 μg N2O-N m-2 h-1. In the urine-affected soil, nitrification and denitrification contributed equally to the N2O emission, and the increased N2O loss resulted from a combination of higher rates and higher N2O loss ratios of the processes. In the present study, an enhanced nitrification rate seemed to be the most important factor explaining the high initial N2O emission from urine patches deposited on well-aerated soils.

Two case studies on Danish sandy loams investigated long-term effects of fertilization and crop rotation. Case Study 1 compared a diversely cropped organically farmed soil (DFG(1)) with a conventionally farmed soil predominantly growing annual crops (DFA), both receiving animal manure. In Case Study 2, a diversely cropped organically managed soil DFG(2)) receiving animal manure was compared with an almost exclusively cereal cropped conventionally farmed soil receiving no animal manure (CCC). A multi-level experimental strategy was followed to compare integrating field methods with specialized laboratory methods. Ease of tillage was described in the field and characterized using a drop shatter field test and by measuring aggregate tensile strength. Fitness as a seedbed was characterised visually in the field and from the drop shatter test. Impedance to seedling emergence and root penetration was evaluated by measuring bulk soil shear strength. For Case Study 1, soil tilth was better for the DFA soil than for the DFG(1) soil (i.e. lower soil strength and higher ease of fragmentation and friability index for DFA). However, a crumbly structure and a moderate bulk density suggested that the DFG(1) soil was also a favourable medium for plant growth. For Case Study 2, the CCC soil had a lower organic matter content, higher bulk density, higher soil strength, and lower ease of fragmentation in comparison with the DFG(2) soil.

Application of organic residues to soil is generally assumed to improve soil tilth. Only few studies have reported on the long-term effects on the more subtle aspects of soil porosity and no reports have considered the potential effects of organic amendments on the pore system in the subsoil. We sampled undisturbed soil cores (100 cm3 and 6280 cm3) in metal cylinders in differently fertilized plots in the long-term field experiments at Askov Experimental Station, Denmark. We selected the 0-60 cm soil layer of plots dressed for a century with either mineral fertilizers (labelled NPK) or animal manure (labelled AM). Both fertilization treatments were studied at two levels of nutrient application: 'normal' (labelled '1') and 1.5 times 'normal' (labelled '11/2'). Plots unfertilized for a century (labelled UNF) were included as a reference for some of the studies. Water retention, air permeability and air diffusivity were measured on the small cores, and we used the large cores for measuring near-saturated and saturated hydraulic conductivity. In the plough layer, the AM and NPK soils displayed identical pore volumes in size fractions larger as well as smaller than 30 micrometer, while the UNF soil had a significantly smaller volume of pores

Nitrate leaching from crop rotations supporting organic grain production was investigated from 1997 to 2000 in a field experiment at three locations in Denmark on different soil types. Three experimental factors were included in the experiment in a factorial design: (1) proportion of N2-fixing crops in the rotation (crop rotation), (2) catch crop (with and without), and (3) manure (with and without). Three, four-course rotations were compared, two at each location. The nitrate leaching was measured using ceramic suction cells. Leaching losses from the crop rotation with grass–clover green manure and without catch crops were 104, 54 and 35 kgNha21 yr21 on the coarse sand, the loamy sand, and the sandy loam, respectively. There was no effect of manure application or time of ploughing-in the grass–clover green manure crop on the accumulated nitrate leaching from the entire rotation. Catch crops reduced nitrate leaching significantly, by 30–38%, on the sandy soils. At all locations catch crops reduced the annual averaged nitrate concentration to meet drinking water quality standards in the crop rotation with green manure. On the coarse sand there was a time lag between the onset of drainage and the start of N-uptake by the catch crop.

The choice of growing media and the strategy of application of organic fertilizers is considered one of the largest challenges for production of organic tomato plantlets for transplanting. We have measured the growth and the ability of young tomato plantlets to extract plant nutrients from an organic growing media. Plants were grown in 0.45L pots. Plant nutrition were either entirely based on the mineral nutrients, available from the organic growing media or based on a combination of nutrients from the organic growing media and fertigation with water-soluble organic fertilizers during plantlet production. The first results shows that plant dry weigth and uptake of nitrogen, phosphorus and potassium was reduced in the organic growing media compared to the control, peat based growing media, but the results also indicate a possibility for optimizing the suggested organic growing media in order to increase the nutrient acquisition and utilization efficiency of the plants. Improved organic growing media can supply most of the necessary plant nutrients needed for the plant, limit the need for supplementary fertilisation, and be an alternative to conventional production with inorganic fertilizers.

Trials were performed with red beet and white cabbage in 1998-2001 to assess the effects on yields and nutrient utilization of surface mulch (chopped grass and/or red clover). No other nutrients were applied. Nitrogen (N), phosphorus (P) and potassium (K) contents were measured in mulch, saleable products and above-ground plant residues. A single mulch application of about 12 Mg DM ha-1 increased the yields of both crops significantly. Mean yields of saleable products were increased from 27 to 33, and from 44 to 56 Mg FW ha-1 of red beet and white cabbage, respectively. However, the average apparent recoveries of mulch derived nutrients in above-ground plant parts (calculated by subtraction of uptakes in the control treatment) were only 13%, 14% and 18% of N, P and K, respectively. Some 3-10% of the N supplied in mulch was found as mineral N at 0-60 cm soil depth after harvest, and in late autumn approximately half of the P and all the K supplied was found as P-AL or K-AL (ammonium lactate and acetic acid) plus acid-soluble K in the topsoil. Mulch application also increased the yield level of spring cereals grown in the following year by on average 0.6 Mg ha-1, or 20%.

Nitrogen nutrition of plants in organic farming depends largely on animal manure. In a pot experiment the hypothesis was tested that on a long-term organically managed soil (ORG) characterized by higher soil microbial activity, a greater portion of N applied as cattle manure is mineralized and taken up by plants than on a conventionally managed soil that had received exclusively mineral fertilizers (MIN). Dry matter yields and N uptake by Italian ryegrass were higher by around 20% on ORG than MIN soil. The N utilization of 15N labeled animal manure components and mineralNdiffered little between ORG and MIN. The major part of the increasedNuptake on ORG compared with MIN was due to a significantly greater N supply from ORG soil. The increased capacity of the ORG soil to supply N to plants became more important at later cuts when N was severely limiting plant growth.

Injection of liquid manure (slurry)into the soil is an alternative to the traditional surface application. By the injection method,it is possible to place nutrients closer to the crop sown, thus offering the crop a competitive advantage over weeds. This study compares the response in crop yield, weed density and weed biomass to injection vs. surface application of liquid manure through three growing seasons in barley and oats. The manure applications were combined with treatments of weed harrowing or herbicide spraying or no treatment at all. The levels of weed control and crop yield obtained by harrowing and herbicides were larger when slurry was injected compared with surface application. Without any weed control treatments,the injection method decreased the final weed biomass in barley. The in fluence of nutrient injection on yield and weed control seemed to be modulated by the time of emergence and the early growth rate of the crop relative to weeds. Thus, because of its early root growth and development, barley responded more quickly to the injection treatment than oats. Consequently, barley became a more competitive crop.

The growth potential of grass-clover leys as influenced by cattle slurry application and clover content was studied in field experiments during three growing seasons at four locations. A grassland growth model was used to quantify growth potential and to separate the influence of weather variables from factors related to the plant stand. Application of cattle slurry increased the initial relative growth rate (R-s), on average from 0.21 to 0.23 g g(-1) day(-1) of the spring growth. In regrowth the effect of cattle slurry was less pronounced. The effect of cattle slurry declined with increasing R-s of the unfertilized treatment and rose with increasing rate of ammonium N applied by the slurry. The positive response to cattle slurry application on R-s was unaffected by the clover proportion in the spring growth, while in regrowth it tended to diminish with increasing clover proportion. A rising clover proportion enhanced the growth potential of the ley in both growth periods. In spring growth, highest R-s was found at an average clover content of approximately 55%, while in regrowth R-s increased linearly with the clover content. On average, slurry application reduced the clover proportion of dry matter yield by 7%-units in spring growth and 13%-units in regrowth.

A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts.

Composting of wastes from citrus industrial processing (pastazzo and sludge) was studied in order to evaluate the evolution of organic matter during the process and to individuate chemical and/or biochemical techniques able to set the stability of the final product. Composts from two open-air piles of different composition were sampled every month during the whole period of composting (5 months) and the organic matter of each sample was characterised by chemical and biochemical techniques. Humification rate (HR%) and humification index (HI) were determined. Extracted organic matter of the six samples collected for each compost was investigated by isoelectric-focusing technique (IEF). The biochemical analysis were based on the study of C-mineralisation after the addition of each collected sample to soil. Results obtained clearly demonstrated organic matter evolution during composting processes. Humification rates increased and humification indexes decreased over time, while extracted organic matter showed electrophoretic behaviour typical of stabilised organic compounds. Moreover, mineralisation patterns confirmed the increased level of organic matter stability during the composting process.

Animal manures and plant-based manures are used for biogas production by anaerobic digestion (AD). After AD the concentration of ammonium-N in manure is increased and the concentration of decomposable C is decreased. Thus, the potential first year fertilizer value of the manure can be increased by the treatment. However, pH is also increased by AD thereby increasing the risk of ammonia losses. The objective of this paper was to compare N turnover in soil after application of digested and corresponding undigested manures, and to compare N fertilizer values of digested manures after direct injection or surface-banding in cereals. After AD of pig and cattle slurry the increase in potential plant availability was equivalent to 10-25% of total manure N. AD of cattle faeces and a mixed cattle diet increased the net mineral N release in soil even more to about 60 and 80% of total N, respectively. The present results indicate that the plant availability of N of digested plant materials is similar to that of digested cattle slurry. After surface-banding of digested manures rich in fibers, such as cattle and plant-based manures, significant ammonia loss can be expected resulting in relatively poor utilization of manure N.

The positive effects on soil tilth from cropping and fertilisation are prone to destructive forces from traffic and tillage. This presentation provides results from a project aiming to quantify the relative importance of crop rotation, fertilisation and traffic/tillage and their interactions. The investigation includes a field trial established 1986 on loamy sand and another initiated 1997 on a sandy loam. All 1986-trial plots are grown with annual cash crops. Annual incorporation of animal slurry and straw residues is compared to reference plots receiving no organic matter. In the 1997-trial, a diversified crop rotation including grass ley and catch crops is compared to a sequence of annual cash crops excluding catch crops. The latter treatment is performed with and without annual application of animal slurry. In both trials, half of all plots were mechanically compacted by tractor the year prior to investigation. The 1986-trial also included part-plots intensively tilled with a rotary cultivator. Results obtained so far in the 1997-trial indicate that soil organic carbon, microbial biomass, hyphal lengths and soil pore volume are significantly increased by manure application but especially by the diverse crop rotation. In contrast, clay dispersibility and wet aggregate stability were not significantly affected. Hence, biological soil attributes may serve as early indicators of soil quality changes. In the 1986-trial, significant effects of the organic matter treatment were apparent for some biological (microbial biomass), chemical (total and hot-water extractable organic C) and physical (bulk soil strength and friability) attributes. The mechanical disturbance by compaction as well as by intensive tillage caused a significant reduction in soil friability though partly alleviated by the organic matter-treatment.

This 3-month incubation study showed that ensiled grass-clover was a better nitrogen (N) source than a composted grass-clover and straw mix (grass-clover:straw, 4:1, w:w), owing to the high content of labile compounds compared to the more degraded compost. Our study also indicated that emissions of the strong greenhouse gas nitrous oxide (N2O) can be reduced by incorporating green manure using harrowing instead of ploughing. The silage-derived N release by the end of the incubation was equivalent to 38-42 kg N ha-1, which corresponded to one third of the N applied in silage, with no difference between ploughing and harrowing. In contrast, no net release of mineral N was detected from the composted grass-clover.

Ensidige sædskifter uden brug af husdyrgødning har vist sig at udpine jorden så meget, at der (bl.a.) bliver problemer med jordens evne til at smuldre under bearbejdning. Økologiske sædskifter vil oftest være så alsidige, at man dér vil opretholde en passende pulje af nydannet, ’aktivt’ organisk stof. Tildeling af husdyrgødning trækker i samme retning. Mekanisk påvirkning af jorden kan eliminere eller i hvert fald reducere de gode effekter af sædskiftet. Der er derfor al mulig grund til at begrænse skadelig pakning af overjorden mest muligt (brug brede lavtryksdæk) samt – om muligt – at undgå brugen af fræser og rotorharver.

Ensilering af kløvergræs og lucerne og anvendelse som mobil grøngødning kan give en høj udnyttelse af det opsamlede kvælstof på økologiske planteavlsbedrifter. Kompostering af grøngødningen kan ikke anbefales, idet det medfører store tab af kvælstof og ringere gødningsvirkning. Gødningsvirkningen er afhængig af grøngødningens protein koncentration.

In the abstract it is discussed how increased biodiversity in the choice of crops, catch crops and green manures can be used to improve organic crop rotations. Use of more species with variable characteristics can make it possible to make rotations with reduced losses of nutrients and improve nutrient supply for organically grown crops.

The utilization of nitrogen (N) in green manure leys can be improved by harvesting, storage and spreading of the plant material as manure in other crops. By green manure storage as silage, storage losses of N are lower than by composting. Also, a relatively high fertilizer value of silage N is achievable depending on the C/N ratio of the material. Nitrogen availability in green manure leys is higher after storage as silage compared to composting. Use of mobile green manures is mainly relevant in arable cropping systems without livestock where utilization of the roughage for animal feed or biogas production is impossible, as costs for ley/roughage harvest and transport can be relatively high. Our study showed that surface application of green manure silage to growing crops can damage plants and is therefore not recommended, whereas incorporation of silage before sowing has significant positive effects on crop yields.