Agri-environmental policies from 1960 to 2022.

For both research and practice, it is paramount to understand what, where and when agri-environmental policies have been put in place. Here we present a database of 6,124 agri-environmental policies implemented between 1960 and 2022 in about 200 countries. The database comprises a wide range of policy types (including regulations and payment schemes) and goals (such as biodiversity conservation, safer pesticide use and reducing nutrient pollution). We illustrate the application of the database by exploring the association between economic development and agri-environmental policies and between the soil-related, agri-environmental policies of countries and their border discontinuities in cropland erosion. A strong, positive link between economic development and implemented agri-environmental policies is revealed, and it is found that 43% of all global border discontinuities in soil erosion between countries can be explained by differences in their policies.

A 'debt' based approach to land degradation as an indicator of global change.

We propose a way to synthesize different approaches to globally map land degradation by combining vegetation and soil indicators into a consistent framework for assessing land degradation as an environmental 'debt'. our combined approach reveals a broader lens for land degradation through global change, in particular, identifying hot-spots for the different kinds of land degradation.

Land use and climate change impacts on global soil erosion by water (2015-2070).

Soil erosion is a major global soil degradation threat to land, freshwater, and oceans. Wind and water are the major drivers, with water erosion over land being the focus of this work; excluding gullying and river bank erosion. Improving knowledge of the probable future rates of soil erosion, accelerated by human activity, is important both for policy makers engaged in land use decision-making and for earth-system modelers seeking to reduce uncertainty on global predictions. Here we predict future rates of erosion by modeling change in potential global soil erosion by water using three alternative (2.6, 4.5, and 8.5) Shared Socioeconomic Pathway and Representative Concentration Pathway (SSP-RCP) scenarios. Global predictions rely on a high spatial resolution Revised Universal Soil Loss Equation (RUSLE)-based semiempirical modeling approach (GloSEM). The baseline model (2015) predicts global potential soil erosion rates of [Formula: see text] Pg yr-1, with current conservation agriculture (CA) practices estimated to reduce this by ∼5%. Our future scenarios suggest that socioeconomic developments impacting land use will either decrease (SSP1-RCP2.6-10%) or increase (SSP2-RCP4.5 +2%, SSP5-RCP8.5 +10%) water erosion by 2070. Climate projections, for all global dynamics scenarios, indicate a trend, moving toward a more vigorous hydrological cycle, which could increase global water erosion (+30 to +66%). Accepting some degrees of uncertainty, our findings provide insights into how possible future socioeconomic development will affect soil erosion by water using a globally consistent approach. This preliminary evidence seeks to inform efforts such as those of the United Nations to assess global soil erosion and inform decision makers developing national strategies for soil conservation.

Why farmers deviate from recommended pesticide timing: the role of uncertainty and information.

BACKGROUND: Precise timing of pesticide applications, as recommended by decision-support systems, can ensure crop protection, while maintaining efficient use of pesticides, yet farmers often deviate from recommended timing strategies. Here, we assess and explain farmers' choices to follow or not follow recommendations for the timing of fungicide applications against potato late blight in Switzerland. RESULT: Based on daily fungicide application records as well as regional application recommendations and disease pressure, we found that 36% of applications took place earlier than recommended. Using regression analysis, we identified the exposure to economic risks of infection, susceptibility of the planted potato varieties to late blight infections, as well as yearly differences in disease occurrence as the most important determinants of farmers' application decision. CONCLUSION: Our results indicate that decisions to not follow application recommendations and apply early are linked to available information and uncertainty with respect to disease predictions. Based on our results, we make recommendations on how to account for farmers' uncertainty with regard to the timing of pesticide applications in the design of pesticide policies and agricultural decision-support systems. These include the use of new technologies and data, mandatory reporting and tailor-made taxes and insurance solutions. Although the focus of this article is on late blight in Switzerland, our analysis can easily be extended to other countries and important plant diseases like powdery mildew in grapevines or Fusarium head blight in winter wheat. © 2020 Society of Chemical Industry.

Countries influence the trade-off between crop yields and nitrogen pollution.

National institutions and policies could provide powerful levers to steer the global food system towards higher agricultural production and lower environmental impact. However, causal evidence of countries' influence is scarce. Using global geospatial datasets and a regression discontinuity design, we provide causal quantifications of the way crop yield gaps, nitrogen pollution and nitrogen pollution per crop yield are influenced by country-level factors, such as institutions and policies. We find that countries influence nitrogen pollution much more than crop yields and there is only a small trade-off between reducing nitrogen pollution and increasing yields. Overall, countries that cause 35% less nitrogen pollution than their neighbours only show a 1% larger yield gap (the difference between attainable and attained yields). Explanations of which countries cause the most pollution relative to their crop yields include economic development, population size, institutional quality and foreign financial flows to land resources, as well as countries' overall agricultural intensity and share in the economy. Our findings suggest that many national governments have an impressive capacity to reduce global nitrogen pollution without having to sacrifice much agricultural production.