Drip irrigation technology in Karnataka, India

This study assesses whether the practice of drip irrigation in Karnataka reduced the usage of groundwater. It finds that while drip irrigation does reduce the quantity of groundwater used per acre, the quantity of the groundwater used per farm does not fall concomitantly, because the irrigation intensity of drip irrigation is greater. Therefore, limiting the area under drip irrigation would make the adoption of the technology sustainable and address food security, and the government should complement the practice of drip irrigation. There is no rebound effect or instance of the Jevons paradox

Assessing the ecological relevance of organic discharge limits for constructed wetlands by means of a model-based analysis

Polder watercourses within agricultural areas are affected by high chemical oxygen demand (COD) and biological oxygen demand (BOD5) concentrations, due to intensive farming activities and runoff. Practical cases have shown that constructed wetlands (CWs) are eco-friendly and cost-effective treatment systems which can reduce high levels of organic and nutrient pollution from agricultural discharges. However, accumulated recalcitrant organic matter, originated by in-situ sources or elements of CWs (i.e., plants or microbial detritus), limits the fulfilment of current COD discharge threshold. Thus, to evaluate its relevance regarding rivers ecosystem health preservation, we analysed the response of bio-indicators, the Multimetric Macroinvertebrate Index Flanders (MMIF) and the occurrence of organic pollution sensitive taxa towards organic pollutants. For this purpose, statistical models were developed based on collected data in polder watercourses and CWs located in Flanders (Belgium). Results showed that, given the correlation between COD and BOD5, both parameters can be used to indicate the ecological and water quality conditions. However, the variability of the MMIF and the occurrence of sensitive species are explained better by BOD5, which captures a major part of their common effect. Whereas, recalcitrant COD and the interaction among other physico-chemical variables indicate a minor variability on the bio-indicators. Based on these outcomes we suggest a critical re-evaluation of current COD thresholds and moreover, consider other emerging technologies determining organic pollution levels, since this could support the feasibility of the implementation of CWs to tackle agricultural pollution

Efectos de covariantes en la distribuci´on de la disponibilidad apagar por el m´etodo de turnbull

Este art´ıculo pretende servir como una gu´ıa para la implementaci´on del m´etodo de Turnbull aplicado a la investigaci´on sobre valoraci´on contingente. En ´el se discutir´a la metodolog´ıa y se implementar´an algoritmos de soluci´on para calcular los estimadores necesarios en SCILAB 4.1, un lenguaje de prop´osito general orientado a matrices. Como parte de la discusi´on, se tratar´an varios problemas pr´acticos que surgen en el manejo de datos en este formato. Finalmente, se probar´a la implementaci´on como parte de un estudio de valoraci´on contingente, donde analizar´an aspectos relevantes de la disponibilidad a pagar por una pol´ıtica p´ublica para mitigar los efectos de externalidades negativas relacionadas con la enfermedad del VIH/SIDA. Se enfatizar´a el efecto que tiene sobre esta medida que tiene la percepci´on del riesgo de infecci´on (definido como covariante)

Ecosystem services and agriculture : case studies in the Guayas River Basin, Ecuador

Global food security faces major challenges related to understanding and optimizing land and water management, in balance with the ecological carrying capacity. Several authors acknowledge that current land use and agricultural management patterns lead to diverse impacts in land and water resources. The Guayas River Basin (GRB) is the most important source of agricultural revenue for Ecuador, with existent and newly built structures that introduce potential benefits to agricultural and other productive activities, but also create pressures for the upcoming years. While the GRB and its estuary are a source of major agricultural export products (bananas, cocoa, among others), there is a constant struggle between agricultural expansion and biodiversity. Particularly, intensive use of certain agricultural practices (e.g. irrigation, chemical fertilizers and pesticides, etc.) may pose a severe threat for water and soil quality, soil health, species diversity and other key environmental indicators. The concept of Ecosystem Services (ES) was originally introduced by the Millennium Ecosystem Assessment (MEA, 2003; MEA, 2005) and was extensively extended and refined considering these challenges. ES can be defined as the conditions, processes, and components of the natural environment that provide tangible and intangible benefits for the sustainability of human life. The ES concept addresses social-ecological systems holistically by recognizing the complex ecological grounding of ES, i.e. that benefits to human well-being are strongly connected to the functioning of ecosystems. According to Seppelt et al. (2011), the MEA and other ES frameworks did not provide consistently operational methods to implementation with sufficient tools for taking provisioning of natural goods and services into account. As a response to these issues, more recent frameworks emerged, such as the Common International Classification of Ecosystem Services (CICES), which proposes a broad equivalence model between major current ES frameworks. This dissertation adopts this conceptual framework to frame the problematic of the GRB socioecological system by providing an up to date, concise survey of the state of the art in ES research in the context of agroecological systems. Then, the findings put forward for the interdependence of agricultural landscape management in the system with flows of ES and ES bundles are put into the broader context of potential contributions to the body of ES literature. Chapter 2 carries this forward and introduces a systematic overview of the existing literature on the interdependence of continental ES and agricultural and landscape management, as well as providing a methodological framework to explore potential gaps in this body of literature. Chapter 3 delves into the dichotomy described in the previous section encompassing agricultural production and environmental degradation in the GRB. The ES framework is employed to uncover insights into ecosystem functioning in relation to exploitation that are needed as a basis for socioeconomically acceptable mitigation of these impacts. A Bayesian Belief Network (BBN) model is developed to link three major ES (i.e. food production, water provision and ecotourism) and determine the effect of local agricultural practices and management on provision of these ES in the GRB. Chapter 4 then builds upon the exploratory insights put forward by the TEEB-Cocoa project for a case study situated in Los Rios province. These insights are taken forward by focusing on ES bundles for soil supporting services that are integrated to a modelling framework aimed to understand the nature of potential tradeoffs between these bundles and those related to provisioning services in local coca production systems. Chapter 5 builds upon the insights provided in the previous chapter about the role of intensive agricultural practices and takes irrigation adoption as a key practice. Thus, the aim in this chapter is centered on understanding the main drivers behind adoption of such practices. Chapter 6 wraps up and presents a short synopsis and discussion of the main findings directed at answering the research questions addressed in previous chapters, as well as the limitations that were found during the research process. The discussion in this chapter starts by providing insights and management recommendations based on specific findings for the context of the GRB. Then, effort is invested in contextualizing the methodologies, findings and limitations developed in this dissertation in the context of the general structure of the literature unveiled in chapter 2 to identify the scope of the research contributions of this doctoral dissertation

Small and mid-sized farmer irrigation adoption in the context of public provision of hydric infrastructure in Latin America and Caribbean

According to 2013 statistics from the Economic Commission for Latin America and the Caribbean (EC-LAC 2013), a mere 3.03% of the total agricultural area in aEuroiaEuroithe region uses some type of irrigation technology. Thus, there is a high degree of sub-utilization of existing hydric infrastructure given that the supply of irrigation capacity in many countries is greater than the calculated use (see Herrera et al. 2005; IICA 2011; CONAGUA 2014, among others). Nonetheless, there are a limited number of studies that characterize the factors affecting the adoption of irrigation by small and mid-sized farmers in the influence area of irrigation projects. This manuscript presents a novel empirical decision model applicable to irrigation adoption based on exogenous and endogenous factors in the context of LAC countries, which is solved through a binary equation system with latent variables. The main goals are to capture the effect that certain idiosyncratic variables, such as lack of credit access, can have over the decision of irrigation adoption; as well as the costs associated to private goods, financed through credit, which are necessary to access to the benefits of the provision of irrigation as a public good

Understanding constraints on private irrigation adoption decisions under uncertainty in data constrained settings : a novel empirical approach tested on Ecuadorian Cocoa cultivations

In rural areas of LatinAmerican Countries, irrigation requirements for perennial crops, like cocoa are expected to increase. This paper develops a novel holistic approach to model private investment decisions in irrigation adoption by small and mid-sized cocoa farmers that face competing sources of uncertainty. In agricultural studies data collection through surveys often leads to issues of missing information on key measured variables. Our approach deals simultaneously with the issue of endogeneity of considering diverse risk sources and with the missing values in key covariates. The study considers multiple levels of irrigation adoption in a context where traditional and modern irrigation systems might coexist. The main contributions of this paper are both its methodological approach and its empirical application filling a knowledge gap on irrigation adoption

Bayesian Belief Network models as trade-off tools of ecosystem services in the Guayas River Basin in Ecuador

Food production often leads to environmental degradation. Consequently, insights into ecosystem functioning in relation to exploitation are needed as a basis for socioeconomically acceptable mitigation of these impacts. A Bayesian Belief Network (BBN) model is developed to link three major ecosystem services (ES), i.e. food pro-duction, water provision and ecotourism, and determine the effect of local agricultural practices and manage-ment on the ES in the Guayas Basin (Ecuador). Several data sources were integrated into the BBN model, in-cluding processed spatial data from primary and secondary sources, sampling and survey data, and expert knowledge. The model suggests that banana and sugar cane generate the highest yield but provide low eco-tourism benefits. In contrast, cacao produces the lowest yields but contributes to better water quality. Scenario analyses suggest that environmental gains are possible by optimising the land use (LU) based on the edapho-climatic requirements of crops. Moreover, the integration of LU optimisation with upscaling and farming in-tensification can allow for additional advantages in water provision and ecotourism while mitigating pro-ductivity losses. The BBN development approach can serve as a reference for other case studies, where data scarcity plays a limiting factor in the assessment of interactions between key ES