Food security concerns and the scarcity of new productive land have put productivity enhancement of degraded lands back on the political agenda. In such a context, salt-affected lands are a valuable resource that cannot be neglected nor easily abandoned even with their lower crop yields, especially in areas where significant investments have already been made in irrigation and drainage infrastructure. A review of previous studies shows a very limited number of highly variable estimates of the costs of salt-induced land degradation combined with methodological and contextual differences. Simple extrapolation suggests that the global annual cost of salt-induced land degradation in irrigated areas could be US$ 27.3 billion because of lost crop production. We present selected case studies that highlight the potential for economic and environmental benefits of taking action to remediate salt-affected lands. The findings indicate that it can be cost-effective to invest in sustainable land management in countries confronting salt-induced land degradation. Such investments in effective remediation of salt-affected lands should form part of a broader strategy for food security and be defined in national action plans. This broader strategy is required to ensure the identification and effective removal of barriers to the adoption of sustainable land management, such as perverse subsidies. Whereas reversing salt-induced land degradation would require several years, interim salinity management strategies could provide a pathway for effective remediation and further showcase the importance of reversing land degradation and the rewards of investing in sustainable land management

The Environmental Stewardship Scheme provides payments to farmers for the provision of environmental services based on foregone agricultural income. This creates a potential incentive compatibility problem which, combined with information asymmetry about farm land potential, can lead to adverse selection of land into the Scheme and therefore a less cost-effective provision of environmental goods and services. However, the Higher Level Stewardship (HLS) Scheme design includes some features that potentially reduce adverse selection. This paper studies the adverse selection problem of the HLS using a principal-agent framework at the regional level. It is found that, at the regional level, the enrolment of more land from lower payment regions for a given budget constraint has reduced the adverse selection problem through contracting a greater overall area and thus higher overall environmental benefit. In addition, for landscape regions with the same payment rate (i.e. of the same agricultural value), differential weighting of the public demand for environmental goods and services provided by agriculture (measured by weighting an environmental benefit function by the distance to main cities) appears to be reflected in the regulator's allocation of contracts, thereby also reducing the adverse selection problem. Copyright (c) 2010 The Authors. Journal compilation (c) 2010 The Agricultural Economics Society.

The effects of zero tillage and residue conservation in continuous maize-cropping systems are poorly documented, especially in the tropics, and are expected to vary highly with climatic conditions and nitrogen availability. In the present study, maize was cultivated during the wet and dry seasons in central Mexico for three consecutive years, under different treatments combining tillage with residue management techniques and with nitrogen rates. In some treatments, maize was also intercropped with jackbean, Canavalia ensiformis L. (DC). Yield and yield components as well as physiological traits and soil characteristics were assessed during the wet and dry seasons for the third year of cultivation. During the wet season, zero tillage was associated with less biomass and grain yield. Leaf chlorophyll concentration was smaller under zero tillage, suggesting less nitrogen uptake. Both zero tillage and residue conservation reduced early growth and strongly increased ear rot. During the dry season, zero tillage was associated with greater root mass, as measured by electrical capacitance. Residue conservation decreased the anthesis-silking interval, suggesting better water uptake. There was, however, no significant effect of tillage or residue management practices on yield. Zero tillage was found to be associated with increased soil bulk density, nitrogen concentration and microbial biomass organic carbon. Residue conservation increased soil carbon concentration as well as microbial biomass organic carbon. Intercropping with jackbean and conservation of its residues in addition to maize residues increased soil nitrogen concentration. Further investigation may provide more information on the factors related to zero tillage and residue conservation that affect maize early growth, and determine to which extent the observed modifications of soil chemical and physical properties induced by conservation tillage will further affect maize yield.

No abstract

Van Iseghem, S., Quillérou, E., Brigaudeau, C., Macher, C., Guyader, O., and Daurès, F. 2011. Ensuring representative economic data: survey data-collection methods in France for implementing the Common Fisheries Policy. – ICES Journal of Marine Science, 68: 1792–1799. Since 2001, Ifremer has implemented an economic data collection programme (EDCP) within the Data Collection Framework of the EU. It aims to obtain economic data from a sample of vessels representative of the entire French fishing fleet. This paper presents the strategies used for vessel sampling selection in the French EDCP and its implementation over several consecutive years. The approach is illustrated by the sampling plan for the fleet in the North Sea Channel Atlantic region. We show that the EDCP allows precise economic indicators such as gross revenue or fuel costs to be estimated for the whole fishing fleet, including small vessels (<10 m), and consequently, it facilitates sound scientific advice regarding the Common Fisheries Policy. The apparent underestimation of landings by small vessels in official statistics is highlighted.

Quillérou, E. and Guyader, O. 2012. What is behind fleet evolution: a framework for flow analysis and application to the French Atlantic fleet – ICES Journal of Marine Science, 69: 1069–1077. The study of fishery dynamics considers national-level fleet evolution. It has, however, failed to consider the flows behind fleet evolution as well as the impact of the dynamics of owners of invested capital on fleet evolution. This paper establishes a general conceptual framework which identifies different vessel and owner flows behind fleet evolution and some relationships between these flows. This descriptive conceptual framework aims to change the current focus on drivers of fleet evolution to drivers of the flows behind fleet evolution. We identify a direct impact of vessel flows on the fleet size and nature, and an indirect impact of the movements of capital owners on the fleet evolution (size and nature). This conceptual framework is illustrated using French Atlantic fleet data over a 15-year period (1994–2008). It is shown that the identified flows vary in size and nature and therefore impact differently on the fleet evolution. This description also shows some dependence of vessel flows on owner dynamics. This relationship should be better taken into account for more effective capacity management.

Land degradation has become a growing concern with the current increase in demand for arable land. Sustainable land management and land restoration practices are required in order to meet the demands to provide food and other services. Adoption of improved practices has however not been widespread partly due to a lack of clarity on the true economic value and setting of proper financial incentives. This article focuses on the economic costs of land degradation as a prelude to two on-going initiatives involving the United Nations Convention to Combat Desertification (UNCCD). We review how ecosystem services derived from land have been economically valued to date. Economic valuation has mostly focused on the use value of provisioning services and cultural services, with limited valuation of non-use value of cultural services. Also, no unique valuation method has been applied following methodological developments, varying study objectives and data availability constraints. These factors impair coherent and consistent estimation of the total economic value of land degradation across Quillérou and Thomas Costs of land degradation and benefits of land restoration2/34 countries. We identify a need to develop harmonised valuation methods to estimate total economic value under strong data and capacity constraints. We propose two alternative frameworks for harmonised total economic valuation of land degradation at country-level to guide further research in making environmental valuation more relevant and practical under strong data and capacity constraints.

Over the past decades fisheries policies have been mainly aimed at encouraging capacity reduction in over-exploited fisheries. Correspondingly, research has focused on developing incentives to exit fisheries rather than investigating entry behaviour.However, with ageing and also fewer fishery participants, concern regarding sectoral renewal is increasing. The second-hand market is an important entry point for first-time owners because it potentially reduces capital constraints by supplying cheaper vessels than newly built ones. The aim of this study is to test whether new fishers entering the industry face greater capital constraints than fishers already in the industry, taking the second-hand market as our population of interest. We model new entry into the fishing sector using 18 years of French Atlantic fleet data with a logit model. We incorporate trade network variables and family connections indicative of the relationship and connections between market traders potentially reducing capital constraints. As expected, we find that first entry is more likely by younger owners for older and cheaper vessels. This suggests that first-time owners are more capital constrained than fishers already trading on the second-hand market. Capital constraints are reduced by geographical proximity and increased integration into a trading network.