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We organized a large-scale pilot on gypsum amendment of arable fields in southwest Finland, along the River Savijoki to examine its effects on phosphorus loads and aquatic environment, and to assess its feasibility as a water protection measure. This paper reports findings on the feasibility aspects of gypsum amendment covering logistics and costs of spreading, abatement potential and farmers’ experience. We found that farmers perceived gypsum amendment positively and the costs of reducing phosphorus are low relative to other measures available in agriculture. Gypsum amendment suits well to 0.5 million hectares of arable land in southern Finland. Gypsum could potentially contribute considerably to the achievement of phosphorus reduction targets of the Baltic Sea Action Plan if applied in all countries having clay soils.

Livestock production in developed countries has undergone profound changes in recent decades and this development seems to continue apace. One consequence is that manure is being - and will be - produced on fewer but larger farms. Data on the bulk of manure nutrients from each country are published by Eurostat, but it is not known how manure is distributed across farms of different sizes. This study 1) puts forward an estimate of the distribution of main manure nutrients between farms of different sizes, 2) estimates how this distribution will change in the near future and 3) discusses the land use effects of this development. Results suggest that by the year 2030 farms housing > 500 livestock units will produce more than two-thirds of all manure phosphorus, whereas the proportion in 2010 was one-third. With the Nitrates Directive limiting the use of organic nitrate of manure, growing farms need to acquire, or conclude contracts for the use of, 4.9 million hectares from exiting farms or the open market in order to comply with manure spreading requirements. This shift will involve 64% of the total spreading area of 2010 and 15% of the total utilized agricultural area of the regions studied. In light of these predictions, international nutrient policies should consider the evolution of farm structure in general and manure phosphorus agglomeration in particular. Also salient is improved co-operation beyond the single farm level to ensure the functionality of crop-livestock systems.

To successfully combat eutrophication caused by agricultural P loads, we need to understand how various forms of P respond to mitigation measures and thus how they contribute to algal growth. Failure to balance mitigation measures targeting dissolved inorganic P (DIP) and P in eroded soil (PP) may lead to economically inefficient measures at best, and to aggravated eutrophication at worst. We model dynamically optimal eutrophication management in a P-limited and SO4-containing water body by taking into account the O2 available and the coupling between the C, Fe, S and P cycles. We show that optimal management would put more weight on mitigating DIP than PP, and that the emphasis on DIP should be particularly strong in eutrophic water bodies. To foster influential and cost-efficient policies, we urge defining water body-specific multipliers to commensurate the main P forms into eutrophying phosphorus, much as greenhouse gases are converted to their CO2 equivalents.

Large animal facilities generate manure in excess of their production needs leading to excessive nutrient loading. Differences in manure contents of phosphorus and nitrogen relative to crop requirements exacerbate loading of the more abundant nutrient, frequently phosphorus. Current regulations that restrict manure utilization and animal production, but not at crop lands leads to suboptimal resource allocation and under utilization of manure in crop production. The transboundary character of nutrient loading further complicates the management of manure phosphorus and nitrogen. Due to differences in environmental characteristics, upstream and downstream regions may have differing objectives towards controlling nitrogen and phosphorus surpluses. We consider optimal management of manure in a stylized two-agent, two-nutrient and two-region model. We show that trade-offs in managing manure phosphorus and nitrogen, inability to regulate manure applications outside animal farms’ field areas and regional differences in environmental targets can severely impede the effectiveness of regulation. Depending on the environmental and economic characteristics, tightening upstream regulation with respect to the loading of one nutrient might increase the downstream loading of the other and might even decrease the total welfare.

This study analyzes the economic feasibility of gypsum amendment as a means to reduce particulate and dissolved phosphorus loads from arable areas. To this end, an optimization model is developed that includes gypsum amendment as well as matching phosphorus fertilization to crop need and the level of soil phosphorus reserves as phosphorus load mitigation measures, with soil phosphorus reserves measured by soil test phosphorus (STP). The optimal extent of gypsum amendment is then determined simultaneously with optimal fertilization use as a function of field STP level. The results indicate that whether or not gypsum amendment is economically feasible depends on field erosion susceptibility and STP level. When accounting for the costs and benefits to the society on the whole, gypsum treatment suits best to mitigation of phosphorus losses from soils with excessively high phosphorus reserves; once a threshold STP level is reached, gypsum amendment is optimally given up. This threshold level depends on field slope and on society’s willingness to pay for water quality.

This article puts forward a model of the role of phosphorus in crop production, soil phosphorus dynamics and phosphorus loading that integrates the salient economic and ecological features of phosphorus management, with grain production in southern Finland as an application. The model accounts for the links between phosphorus fertilization, crop yield, accumulation of soil phosphorus reserves, and phosphorus loading into waterways. It can be used to guide precision phosphorus management as a means to mitigate agricultural phosphorus loading. Erosion control is considered as an additional measure to reduce phosphorus loading through soil loss. A dynamic programming approach and numerical solution method are used to analyze the intertemporally optimal combination of fertilization and erosion control and the associated soil phosphorus development. The optimal fertilizer application rate changes markedly over time in response to changes in the soil phosphorus level. Erosion control was found to increase welfare only on land that is highly susceptible to erosion.

The Baltic Sea and the Chesapeake Bay share many characteristics. Both are shallow, brackish marine areas that suffer from eutrophication. Successful policies targeting point source pollution have lowered nutrient loads in both areas, but achieving the desired marine quality will require further abatement: efforts may be extended to more complicated and expensive pollution sources, notably agricultural nonpoint loads. Despite their ecological similarities, the two watersheds have different histories and institutional settings and have thus adopted different policies. Comparing and contrasting the policies reveal ways to improve the efficiency of each and ways to avoid the path of trial and error. No comparison of the parallel protection efforts, which involve expenditures of hundreds of millions of dollars annually, has been carried out to date. The present paper analyzes the policies applied in the two regions, distilling the results into six recommendations for future steps in preserving what are valuable sea areas.

Agriculture is facing stringent requirements for nutrient loss reductions. These reductions should be done cost-effectively. For instance, the European Water Framework Directive (WFD) emphasizes cost-effectiveness in reaching good water status in European river basins by 2015. River Basin Management Plans specify the eventual reduction targets, which will differ between the basins. These differences have implications on cost-effectiveness assessments: changing the level of total abatement changes the relative shares of measures in the cost-effective allocation. In this paper we develop a model which determines the cost-effective allocation of three alternative measures to reduce phosphorus loss from fields. The model allows for comparisons with cost and reductions of all possible allocations. We show that, even for homogenous regions, the cost-effective allocation of measures is strongly dependent on the target level, and that using the allocation from one reduction level as a guideline for other levels violates cost-effectiveness seriously. On the grounds of these results we give recommendations for cost-effectiveness assessments in the context of the WFD., Maatalouden ravinnekuormituksen vähentämiseen onsuuria paineita, ja vähennyksiltä edellytetään usein kustannustehokkuutta. Esimerkiksi EU:n vesipuitedirektiivi edellyttää kustannustehokkuustarkastelua niiltä ylimääräisiltä toimenpiteiltä, joita ympäristöllisiin tavoitteisiin pääseminen vuoteen 2015 mennessä edellyttää. Vesiensuojelualueille asetettavat mahdolliset vähennystavoitteet saattavat poiketa toisistaan merkittävästi. Tämä vaikuttaa kustannustehokkuusanalyysien soveltuvuuteen eri alueiden välillä. Tässä tutkimuksessa pyritään esittelemään ja kvantifioimaan näitä vaikutuksia. Ratkaisemme kustannustehokkaan suojeluratkaisun kolmen eri vesiensuojelumenetelmän kesken fosforin vähennyksen eri tavoitetasoille, ja vertailemme suojeluratkaisujen kustannustehokkuutta eri mittakaavassa toteutettuna. Osoitamme, että jopa homogeenisten alueiden kustannustehokkaat suojeluratkaisut riippuvat voimakkaasti vähennysten kokonaistasosta. Näin ollen eri alueet eivät voi suojelussaan toteuttaa kustannustehokkuutta soveltamalla toisten, vaikkakin samankaltaisten, alueiden kustannustehokkaita suojeluratkaisuja omalle alueelleen, mikäli vähennystavoitteet eroavat toisistaan. Tulosten perusteella otamme kantaa kustannustehokkuusanalyysin käyttöön vesipuitedirektiivin yhteydessä.

We analyze dynamically optimal eutrophication management using two controls, targeted fishing and reduction of external nutrient loads. Fishing removes nutrients from the water ecosystem, and the size of the fish stock also influences eutrophication through food web effects and other mechanisms. We show that fisheries have a role to play in cost-efficient water quality management in combination with external load reductions. Our numerical application considers phosphorus driven eutrophication, agricultural phosphorus abatement and fisheries targeted on cyprinids on a coastal bay in the Baltic Sea. The socially and privately optimal intensity of fishing efforts, phosphorus abatement and the resulting water quality are influenced by damages, revenues and costs. Furthermore, we show that the link between cyprinid fish stock and water quality, and the form of the fishing industry — sole owner or open access — have joint dynamics that lead to very different outcomes. A weak link between cyprinid stock and water quality is associated with socially optimal stock close to its maximum sustainable yield. This maximizes phosphorus removal. With a strong link, socially optimal stock and phosphorus removal are low. Coincidentally, open-access fishing sometimes yields socially desirable outcome automatically — a market failure in industry structure may counteract eutrophication.