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The Mar Menor is a coastal lagoon increasingly threatened by urban and agricultural pressures. The main watercourse draining into the lagoon is the Rambla del Albujón. A fortnightly campaign carried out over one annual cycle enabled us to characterize the treated urban sewage effluents and agricultural sources which contribute to the nutrient fluxes in the watercourse. Multivariate analysis provided information for establishing chemical signatures and for assessing the relative influence of the various sources on the water quality at the outlet. Mass balances were used to examine net gains and losses, and cross-correlations with rainfall to analyze climatic influence and control factors in the trends of the nutrient flux. The rainfall pattern was significantly cross-correlated with nitrate and phosphorus fluxes from agricultural sources, while fluctuations in the resident population explained the phosphorus flux trend in urban sources. 50% of dissolved inorganic nitrogen was from agricultural sources, while 70% of total phosphate and 91% of total organic carbon were from urban point sources. The net amounts of all the nutrients fell as a result of plant uptake and/or denitrification in the channel. The control of urban point sources (phosphorus-enriched) is suggested as a promptly action for improving the health of the coastal lagoon. [Copyright &y& Elsevier]

Agroecological practices have been shown to control erosion, increase soil fertility, carbon stocks, pollination and biodiversity. As a consequence, these ecosystem services can contribute to a better farm economic resilience on the long-term; however, empirical evidence is scarce. In this study we aim to understand the economic performance of agroecological practices in almond orchards and the relevance of different economic and policy scenarios to incentivise the upscaling of agroecological practices. We investigated the development of the net present value (NPV) of several agroecological practices (no tillage (NT), green manure (GM) and compost (CM)) as compared to conventional tillage (CT), as well as the effect of internalising externalities through payments for soil carbon sequestration and by costs of erosion. Finally, we explored the effects of price premiums and public greening payments, on farm NPV. We found that all management regimes were profitable and that CM had a 17.2% higher NPV than CT, while both GM and NT had lower NPV than CT (69% for GM and 90.1% for NT). We found that despite NT and GM have higher soil organic carbon stocks, these provided a negligible additional income via carbon markets. CT had the highest externality costs of erosion but still its NPV was higher than NT and GM, despite the strong reductions in costs of erosion in NT and GM conferred by vegetation covers. We found that a price premium of 45% was necessary to make NT's economic performance comparable to that of CT, while a 27% price premium would be needed to make GM comparable to CT. Compensation through public greening payments would be in the order of €644 ha−1 y−1 for NT and €387 ha−1 y−1 for GM to have a similar NPV as CT. Our results suggest a trade-off between income from yield and costs from unaccounted externalities. We also find that private and public policy incentives could reverse this outcome, but requiring a large investment. Of the analysed agroecological practices, compost application appears the most promising to be scaled-up to improve both economic and environmental performance, and further research is needed to determine the outcomes of a combination of compost and vegetation covers. • Agroecological practices in rainfed almonds can be profitable • Compost application resulted in higher profitability than conventional tillage • No tillage and green manure had lower profitability than conventional tillage • Public greening payments and price premiums do not fully compensate for opportunity costs • Payments for soil-based environmental services do not compensate for opportunity costs [ABSTRACT FROM AUTHOR]