Search

The aim of the project Biobased Fertilisers Achterhoek (‘Kunstmestvrije Achterhoek’ in Dutch) is to make fertilisation practices more sustainable through use of locally available nutrients from renewable sources. The project is part of the Sixth Action Programme of the Netherlands, which serves the Nitrates Directive. One of the objectives is to determine the nitrogen fertiliser replacement value of biobased fertilising products made from animal manure. A second objective is to assess the risk of nitrogen leaching from these biobased fertilising products. These objectives were implemented by WUR-Wageningen Environmental Research in a monitoring programme with field experiments on grassland and on arable land with silage maize. This document reports the results of a field experiment on grassland which was conducted in 2020. The field experiment on grassland points on a similar agronomic effectivity of the biobased nitrogen fertilising product compared to calcium ammonium nitrate. The environmental performances of all fertilising products with equal rates of nitrogen were comparable.

The aim of the project Biobased Fertilisers Achterhoek (‘Kunstmestvrije Achterhoek’ in Dutch) was to make fertilisation practices more sustainable through use of locally available nutrients that are derived from renewable sources. The project is part of the Sixth Action Programme of the Netherlands which serves the Nitrates Directive. One of the objectives was to determine the nitrogen fertiliser replacement value of biobased fertilising products that are made from animal manure. A second objective was to assess the risk of nitrogen leaching from these biobased fertilising products. These objectives were implemented by WUR- Wageningen Environmental Research in a monitoring programme which included field experiments carried out on grassland and on arable land with silage maize. This document reports the results of a second field experiment on grassland which was conducted in 2021. These results have indicated that the biobased nitrogen fertilisers tested could serve as a replacement for mineral nitrogen fertiliser.

The aim of the project Biobased Fertilisers Achterhoek (‘Kunstmestvrije Achterhoek’ in Dutch) is to make fertilisation practices more sustainable through the use of locally available nutrients from renewable sources. The project is part of the Sixth Action Programme of the Netherlands which serves the Nitrates Directive. One of the objectives was to determine the nitrogen fertiliser replacement value of biobased fertilising products made from animal manure. A second objective was to assess the risk of nitrogen leaching from these biobased fertilising products. These objectives were implemented by WUR-Wageningen Environmental Research in a monitoring programme that included field experiments on grassland and on arable land with silage maize. This document reports the results of a field experiment with silage maize which was conducted in 2020.

In the context of the Sixth Action Program of the Netherlands for the Nitrates Directive, the Pilot Biobased Fertilisers Achterhoek was implemented. Wageningen Environmental Research supported this pilot with a Monitoring Program that was carried out from 2018 until 2021. The subjects of the Monitoring Program were to investigate the risks associated with blending of bio-based fertilising products, to support demonstration fields in practice, and to carry out four, scientifically based field trials and reports on the research into these subjects. This report is the synthesis report of research results obtained from the Monitoring Program.

The aim of the project Biobased Fertilisers Achterhoek (in Dutch: Kunstmestvrije Achterhoek) is to make fertilisation practice more sustainable by means of the use of locally available nutrients from renewable sources. The project is, as a regional pilot, part of the sixth action program of the Netherlands serving the Nitrates Directive. One of the objectives is to identify the eligible product quality and product composition of fertilising products from animal manure and sludge which can be produced by means of best available techniques for manure and sludge processing. For this objective WUR-Wageningen Environmental Research (WUR-WENR) has developed a monitoring program. A research topic is testing of a new fertilising product from animal manure and other (most renewable) nitrogen sources in demonstration field experiments. The research started in 2018. This document reports the results of the third and last year 2020. De doelstelling van het project Kunstmestvrije Achterhoek (KVA) is het verduurzamen van de bemestingspraktijk door de bemesting van grasland en bouwland zo veel mogelijk in te vullen met regionaal beschikbare nutriënten. Het project is onderdeel, als gebiedsgerichte pilot, van het zesde Nederlandse actieprogramma1 in het kader van de Nitraatrichtlijn. Een van de doelstellingen van het project betreft het identificeren van gewenste productkwaliteit en productsamenstelling van bemestingsproducten van dierlijke mest en slib, beschikbaar komend door toepassing van best beschikbare technieken voor mest- en slibverwerking. Deze doelstelling is door WUR-Wageningen Environmental Research (WUR-WENR) uitgewerkt in een monitoringsprogramma. Een onderdeel daarvan is toetsing van een nieuw bemestingsproduct van dierlijke mest en andere (meest hernieuwbare) stikstofbronnen in demovelden. Dit rapport geeft een vervolg op het onderzoek met demovelden dat in 2018 startte. De resultaten van het derde en laatste jaar van onderzoek uit 2020 worden in dit rapport gepresenteerd.

Het ministerie van Landbouw, Natuur en Voedselkwaliteit wil het gebruik van kunstmest ontmoedigen ten gunste van dierlijke mest. Deze notitie onderzoekt de verschillende financiële prikkels om te stimuleren dat dierlijke mest gebruikt wordt, zoals een heffing op kunstmest of het verstrekken van subsidies. Uit de analyse blijkt dat in de Nederlandse landbouw het gebruik van fosfaat uit dierlijke mest al vrijwel maximaal is. Het gebruik van stikstofkunstmest daarentegen is aanzienlijk. Een heffing op kunstmest is echter weinig effectief omdat de stikstof uit dierlijke mest samen met het fosfaatoverschot via export en verwerking van mest buiten de Nederlandse landbouw wordt afgezet en daarom onvoldoende beschikbaar is. Om zo veel mogelijk stikstof te behouden voor de Nederlandse landbouw is aanpassing van deze mix van mestproducten nodig. Om dit te stimuleren is een subsidie denkbaar op hoogwaardige verwerking van varkens- en rundveedrijfmest.

The aim of this thesis was to improve understanding of the role of organic inputs and soil organic matter (SOM) for crop production in contemporary arable farming in Europe. For this purpose, long-term experiments were analysed on the additional yield effect of organic inputs and savings in mineral fertiliser. In addition, a farm survey was conducted to find drivers and barriers for the use of organic inputs and to assess if arable farmers in Europe perceive a deficiency of SOM. The findings in this thesis suggest that at least on the shorter term, on average, there seems to be no immediate threat from a deficiency of SOM to crop production in arable farming in Europe. The long-term experiments showed that with sufficient use of only mineral fertilisers, on average, similar yields could be attained over multiple years as with the combined use of organic inputs and mineral fertiliser. This was reflected in the farm survey, in which a large majority of farmers indicated not to perceive a deficiency of SOM. Analysis of long-term experiments also showed that more mineral fertiliser N was saved when using farmyard manure at high N rates (with mineral fertiliser application) than at low N rates (without mineral fertiliser application), based on comparisons at equal yield. Specific crops and environments did benefit from organic inputs and more SOM in terms of crop production. Long-term experiments showed that organic inputs give benefit to crop production in wet climates and on sandy soils. In addition, farmers perceived a higher deficiency of SOM on steep slopes, sandy soils, wet and very dry climates. The additional yield effect of organic inputs was significant for potatoes. More in general, farmers who cultivated larger shares of their land with specialized crops (including potatoes, sugar beets, onions and other vegetables) than cereals perceived a higher deficiency of SOM. It seems that while the functions of SOM can be replaced with technical means to a large extent (e.g. tillage, use of mineral fertilisers), there are limits to this technical potential when environmental conditions are more extreme and crops are more demanding. The farm survey revealed that farmers perceive a trade-off between improved soil quality on the one hand and increased pressures from weeds, pests and diseases and financial consequences on the other hand when using organic inputs. If policies aim to stimulate the maintenance or increase of SOM, more insight is needed into the conditions that regulate the pressures of weeds, pests and diseases in response to organic inputs. Financial consequences (at least on the short term) should also be accounted for. More importantly however, benefits from SOM for crop production cannot be taken for granted. Only in specific situations such benefits will exist. If European policies on SOM aim to include benefits for crop production, focus should be on areas with more extreme environmental conditions (very dry or wet climates, steep slopes, sandy soils), or cropping systems with more specialized or horticultural crops rather than cereals.

Maurits Bax uit Luyksgestel werkt met de Yara N-sensor. Zo spuit hij minder dan een derde van de voorgeschreven dosering voor loofdodingsmiddel in aardappelen. Andere toepassingen zijn minder praktijkrijp, zoals aardappelen bijmesten. Daarvoor lijkt een app, ontwikkeld door het PPO, uitkomst te gaan bieden. PPO Lelystad begeleidt het project waar Bax aan mee doet. De teler kreeg de afgelopen twee teeltseizoenen voor zijn aardappelen een adviesgift van PPO op basis van twee systemen: de BemestingsNavigator aardappel van Altic en een systeem dat PPO ontwikkelt. De volgende toepassing was voor het spuiten van halmverstevigers in zomergerst.

Het vijfde Nederlandse Actieprogramma Nitraatrichtlijn biedt ruimte voor zgn. equivalente maatregelen: maatregelen waarbij gebruiksnormen verhoogd kunnen worden zonder dat de milieukwaliteit verslechtert. Dit onderzoek richt zich op evaluatie van N-bijmestsystemen voor aardappel en gebruik als equivalente maatregel. Een theoretische verkenning laat zien dat ideale N-bijmestsystemen die voor verschillende groeiomstandigheden de juiste N-gift geven een iets lager N-overschot geven ten opzichte van bemesting volgens een vaste totale gift. Evaluatie van proeven liet zien dat N-bijmestsystemen mogelijke besparingen ten opzichte van de N-bemestingsrichtlijn veelal goed konden aangeven, maar situaties met een hogere optimale N-gift niet. Daarmee heeft gebruik van N-bijmestsystemen als equivalente maatregel momenteel onvoldoende perspectief.

Spinach (Spinacia oleracea L.) is one of the most consumed leafy vegetables worldwide and it is considered to be highly nutritious. Spinach is a short-cycle leafy crop that has a high demand for nitrogen in order to rapidly come to a harvestable product that has the required dark green colour within a reasonable harvest window. In commercial production of spinach the recovery of N is poor, which may result in environmental pollution. To increase sustainability of both organic and conventional spinach cultivation there is a need to reduce the dependency on high levels of nitrogen. Growers therefore urgently need cultivars with a satisfactory yield under reduced N input conditions. Nitrogen use efficiency (NUE), defined as the ability to produce high biomass per unit N applied, is low in spinach. The present study aims to evaluate spinach genotypes for selectable traits under varying N supply and provide tools and knowledge to facilitate the development of varieties with good yield, quality and stability under low N input. To minimise environmental variation affecting the identification of traits related to NUE a screening method was developed using a hydroponics system. The genetic diversity for NUE related traits was first studied with 24 commercial cultivars under contrasting levels of N supply based on the Ingestad model with a steady-state N application. This demonstrated that the hydroponics screening strategy as a pre-screening tool enabled reliable detection of heritable variation among cultivars for NUE-related traits under optimal as well as suboptimal N input. Shoot dry weight and leaf area were preferred selectable traits for the detection of heritable differences contributing to NUE in spinach. The effect of N application strategy was examined in seven cultivars grown under hydroponics conditions with low and high N levels supplied either as a single bulk N application resembling N fertilization in field cultivation, or a steady-state N application according to Ingestad. The latter application strategy provided more stable and reproducible conditions for determination of genetic differences in NUE under low N conditions for a short-cycle leafy vegetable crop. Several tools for molecular genetic evaluation of NUE in spinach were provided as well, including a SNP marker set for marker-assisted breeding, a genetic mapping population with a corresponding genetic map, and the identification of two major QTL regions contributing to growth under low N conditions. With these tools, an efficient strategy for breeding for NUE efficiency in spinach would include screening under controlled conditions at high and low N using leaf area, biomass and root to shoot ratio as selectable traits, and QTL identification of genetic factors that can be targeted and combined using marker-assisted selection. An in depth genotype by environment interaction analysis using six field trials showed that environmental factors like temperature, soil, and management strongly influence nitrogen availability in the soil in a short cycle crop like spinach. This severely complicates selection and breeding for NUE of spinach under field conditions, and emphasizes the importance of performing trials under better controllable conditions for genetic dissection of NUE and discovery of genetic factors contributing to NUE. It also underscores the importance of validating these findings in various field trials. Multi-environment field trials with different levels of N fertilization will then allow selection of cultivars that combine stable performance under various low input growing conditions with high yields under more favorable conditions.

This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?

Bemestingsnormen moeten voorkomen dat meststoffen het grond- en oppervlaktewater te zwaar belasten. Voor het verkennen van de hoogte ervan is door de Werkgroep Onderbouwing Gebruiksnormen een protocol ontwikkeld. Met kennis van de gewasopbrengst en de efficiëntie waarmee meststoffen door het gewas worden opgenomen, kan worden bepaald welke mestgiften milieukundig verantwoord zijn.

Minder uitspoeling van nitraat naar het grondwater is een doel van het mestbeleid. Bij efficiëntere stikstofbemesting zou het overschot aan stikstof in de bodem moeten dalen. Daarmee zou je verwachten dat ook de nitraatconcentratie in het grondwater vermindert. Maar is dat ook zo?

Zes melkveebedrijven kregen voor onderzoek in 2014 de ruimte om meer kunstmest-N op hun bedrijf te gebruiken dan de generieke gebruiksnormen.

Zes melkveebedrijven kregen voor onderzoek in 2014 de ruimte om meer kunstmest-N op hun bedrijf te gebruiken dan de generieke gebruiksnormen.

Bemestingsnormen moeten voorkomen dat meststoffen het grond- en oppervlaktewater te zwaar belasten. Voor het verkennen van de hoogte ervan is door de Werkgroep Onderbouwing Gebruiksnormen een protocol ontwikkeld. Met kennis van de gewasopbrengst en de efficiëntie waarmee meststoffen door het gewas worden opgenomen, kan worden bepaald welke mestgiften milieukundig verantwoord zijn.

Minder uitspoeling van nitraat naar het grondwater is een doel van het mestbeleid. Bij efficiëntere stikstofbemesting zou het overschot aan stikstof in de bodem moeten dalen. Daarmee zou je verwachten dat ook de nitraatconcentratie in het grondwater vermindert. Maar is dat ook zo?

This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?

Studies on emissions of nitrous oxide (N2O) from agricultural soils mostly focus on fluxes between the soil and the atmosphere or are limited to the atmosphere in the topsoil. However, in soils with shallow water tables, significant N2O formation may occur closer to the groundwater. The aims of this study were (i) to determine the importance of subsoil N2O formation in a sandy soil; and (ii) to obtain a quantitative insight in the contribution of subsoil N2O to the overall losses of N2O to the environment. We applied 15N labeled fertilizer at a rate of 5.22 kg 15N ha−1; 50% as Ca(NO3)2 and 50% as NH4Cl, on a mesic typic Haplaquod seeded with potatoes (Solanum tuberosum L.), and traced soil N2O concentrations and fluxes over a one-year period. Throughout the year, total N2O and the amount of 15N recovered in soil N2O were highest in the subsoil, with a maximum concentration at 48 cm depth in mid-February of 19900 μl m−3 and 24 μg 15N m−3, respectively. The maximum concentration coincided with the highest water-filled pore space of 71%. The cumulative flux of N2O was 446 g N2O-N ha−1, the recovery of 15N in this flux was 0.06%. During the summer, maximum fluxes followed high soil N2O concentrations. During winter, no such relation was found. We concluded that the formation of N2O was the highest in the subsoil, largely controlled by water-filled pore space rather than NO 3 − concentration or temperature. Although high subsoil N2O concentrations did not lead to high surface fluxes of N2O in the winter, artificial draining may lead to high indirect N2O emissions through supersaturated drainage water.Studies on emissions of nitrous oxide (N2O) from agricultural soils mostly focus on fluxes between the soil and the atmosphere or are limited to the atmosphere in the topsoil. However, in soils with shallow water tables, significant N2O formation may occur closer to the groundwater. The aims of this study were (i) to determine the importance of subsoil N2O formation in a sandy soil; and (ii) to obtain a quantitative insight in the contribution of subsoil N2O to the overall losses of N2O to the environment. We applied N-15 labeled fertilizer at a rate of 5.22 kg N-15 ha(-1); 50% as Ca(NO3)(2) and 50% as NH4Cl, on a mesic typic Haplaquod seeded with potatoes (Solanum tuberosum L.), and traced soil N2O concentrations and fluxes over a one-year period. Throughout the year, total N2O and the amount of N-15 recovered in soil N2O were highest in the subsoil, with a maximum concentration at 48 cm depth in mid-February of 19900 mu l m(-3) and 24 mu g N-15 m(-3), respectively. The maximum concentration coincided with the highest water-filled pore space of 71%. The cumulative flux of N2O was 446 g N2O-N ha(-1), the recovery of N-15 in this flux was 0.06%. During the summer, maximum fluxes followed high soil N2O concentrations. During winter, no such relation was found. We concluded that the formation of N2O was the highest in the subsoil, largely controlled by water-filled pore space rather than NO3- concentration or temperature. Although high subsoil N2O concentrations did not lead to high surface fluxes of N2O in the winter, artificial draining may lead to high indirect N2O emissions through supersaturated drainage water.

Veehouders van de ZLTO-afdeling rond de waterwinning van Brabant Water in Loosbroek hebben voor het SKB-project 'Herstel van de natuurlijke buffercapaciteit van de bodem' geïnventariseerd, welke maatregelen het organische stofgehalte op zandgrond kunnen verhogen. Wat betekent een vruchtwisseling van gras en maïs voor het organische stofgehalte, en wat zijn de kosten en baten op een melkveebedrijf met derogatie en zonder derogatie?

In de teelt van stamslabonen voor de industrie worden vaak problemen ondervonden met ziektes zoals Sclerotinia en Botrytis. Deze ziektes worden geassocieerd met (over)bemesting. De gebruiksnorm voor stikstofgift was in 2012 en 2013, 110 kg N/ha respectievelijk 120 kg N/ha, op zand- en kleigrond. Werd er niet bemest dan leidde dit tot een significante opbrengstverlaging. Een overbemesting tot 150% van de gebruiksnorm na aftrek van N-min gaf eveneens een opbrengstverlaging te zien. Bemesting trappen variërend van 50 tot 125% van de normbemesting lieten geen significant verschil in opbrengst zien. Een evenwichtig teeltadvies waarbij het bemestingsniveau maximaal bijdraagt aan plantweerstand en productkwaliteit is belangrijk.

Key words: Nitrogen, phosphorus, food chain, food pyramid, food system, food security, food cost, environmental impacts, nutrient cycling, nutrient management Nitrogen (N) and phosphorus (P) fertilizer applications have greatly contributed to the increased global food production during the last decades, but have also contributed to decreasing N and P use efficiencies (NUE and PUE) in the food production - consumption chain, and to increased N and P losses to air and water, with major ecological implications. The aim of this thesis is to increase the quantitative understanding of N and P flows and losses in the food production - consumption chain in China at regional level in the past 30 years and to develop strategies to increase NUE and PUE in the food chain. A novel ‘food chain’ approach and the NUFER model were developed to analyse N and P flows in crop production, animal production, food processing and retail, and households. Data were derived from statistical sources, literature and field surveys. Between 1980 and 2005, NUE and PUE decreased in crop production, increased in the animal production and decreased in the whole food chain. Total N losses to water and atmosphere almost tripled between 1980 (14.3 Tg) and 2005 (42.8 Tg), and P losses to water systems increased from 0.5 to 3.0 Tg. There were significant regional differences in NUE, PUE, and N and P losses; regions with high N and P losses were in Beijing and Tianjin metropolitans, Pearl River Delta, and Yangzi River Delta. Urban expansion is a major driving force for change; total N losses increased 2.9 folds, and P losses increased even 37 folds during the development of Beijing metropolitan, between 1978 and 2008. Scenario analyses indicated that implementation of a package of integrated nutrient management measures, combined with diet changes and increased imports of animal food and feed, are the most effective management options for increasing NUE and PUE, and for decreasing N and P losses. Application of the food chain approach and the NUFER model can help policy makers in China to plan food production - consumption chains, and thereby manage N and P flows in this chain at regional level.