Peruvian Journal of Agronomy 2(3): 44-53 (2018) ISSN: 2616-4477 (Versión electrónica) DOI: http://dx.doi.org/10.21704/pja.v2i3.1210 © The authors. Published by Universidad Nacional Agraria La Molina Received for publication: 15 November 2018 Accepted for publication: 30 December 2018 Sustainability of lemon (Citrus aurantifolia Swingle) farms in the province of Santa Elena, Ecuador Sustentabilidad de fincas productoras de limon (Citrus aurantifolia Swingle) en la provincia de Santa Elena, Ecuador Santistevan-Mendez, M.1, Borjas-Ventura, R. 1, Alvarado-Huaman, L. 1, Anzules-Toala, V. 1, Castro-Cepero, V. 1, Julca- Otiniano, A. 1* *Corresponding author: ajo@lamolina.edu.pe Abstract The objective was to evaluate the sustainability of lemon farms (Citrus aurantifolia Swingle) in Santa Elena, Ecuador. Surveys were applied to a sample of 83 lemon producers from this province, with structured questions about economic, ecological and socio-cultural dimensions. The sustainability was determined with techniques of multicriteria analysis to calculate the Economic Indicator (IK), Ecological Indicator (IE) and Socio-Cultural Indicator (ISC), to estimate the General Sustainability Indicator (IS Gen) of each farm. The 25.3% of the farms had an IK> 2; 60.24% an IE> 2 and 55.4% an ISC> 2. The 74.7% of the farms had an IS Gen <2, which indicates that the farms are not sustainable. Key words: dimensions, survey, multicriteria, ecological. Resumen El objetivo fue evaluar la sustentabilidad de fincas productoras de limón (Citrus aurantifolia Swingle) en Santa Elena, Ecuador. Se aplicaron encuestas a una muestra de 83 productores de limón de esta provincia, con preguntas estructuradas sobre dimensiones económicas, ecológicas y socio culturales. La sustentabilidad se determinó con técnicas de análisis multicriterio y se calcularon el Indicador Económico (IK), Indicador Ecológico (IE) e Indicador Socio cultural (ISC), para estimar el Indicador de Sustentabilidad General (IS Gen) de cada finca. El 25.3 % de las fincas tuvieron un IK > 2; el 60.24 % un IE > 2 y el 55.4 % un ISC > 2. El 74.7 % del sistema de producción de limón en Santa Elena tuvieron un IS Gen < 2, lo que indica que las fincas no son sustentables. Palabras clave: dimensiones, encuesta, multicriterio, ecológico. 1 Grupo de Investigación Agricultura y Desarrollo Sustentable en el Trópico Peruano. Facultad de Agronomía. Departamento de Fitotecnia. Universidad Nacional Agraria La Molina. Lima (Perú). Introduction Lemons represent approximately 10% of the world citrus production with more than 120 billion tons per year (USDA, 2018). Ecuador produced 28 000 t annual (FAO, 2018), with some provinces as the economic base for the production and commercialization of citrus, especially Citrus aurantifolia Swingle, known as “lime” or “key lime” or “lemon”. This lemon is the most cultivated species and, with the lemon Tahiti (Citrus latifolia Tan), it amounts to approximately 4 965 ha. In Santa Elena province, there are 500 hectares of lemon, cultivated by approximately 400 farmers (PIDAASSE, 2011). Deficiencies in management and technological improvement are crucial for the development of the citrus sector, which must be considered with sustainability criteria (Santistevan et al., 2017). Gómez-Limón & Arriaza (2011), define sustainable agriculture as one that promotes food sufficiency, conserves natural resources, protects the environment and is economically viable. In addition, agricultural farms should not only generate an economic rent, should also maintain the appropriate conditions of the environment so that the crop develops successfully, minimizing disturbances to the natural environment, but above all that allows to improve the quality of life of the agricultural producers. In Ecuador, in recent years, there have been some studies related to the evaluation of sustainability in different agricultural production systems (García, 2015; Santistevan-Mendez, M., Borjas-Ventura, R. , Alvarado-Huaman, L. , Anzules-Toala, V., Castro-Cepero, V., Julca-Otiniano, A. Peruvian Journal of Agronomy 2 (3): 44-53 (2018) 45 Palomeque, 2016; Reina, 2016; Santistevan et al., 2016), using the multicriteria analysis with indicators (Sarandón & Flores, 2009; Sarandón et al., 2016). These studies suggest a different and innovative vision in the analysis of agricultural systems and also in the design of future plans for the agricultural development of this country. In this sense, the present study had the objective of evaluate the sustainability of lemon farms (Citrus aurantifolia) in the Province of Santa Elena, Ecuador. Materials and methods The study was carried out in two rural parroquia of the Santa Elena Canton of the province of Santa Elena, which is located in the Litoral Region, in the extreme west of the Ecuadorian territory (Figure 1) at 2°13’36’’LS and 80°51’29’’LO, with an area of 3,762.8 km2, which represents approximately 1.46% of the Ecuadorian territory (SAMBITO, 2014). From a finite population of 400 lemon producers a random sample of 83 was taken (Scheaffer et al., 1987). To evaluate sustainability, a multicriteria analysis method proposed by Sarandón et al. (2006) was used; the indicators were selected and constructed according to the methodology and conceptual framework proposed by Sarandón (2002) and Sarandón & Flores (2009) adapted for a perennial crop such as lemon. These were integrated by indicators and sub-indicators and whose definition was consulted with technicians and farmers in the area of study (Márquez & Julca, 2015). The information was obtained from a structured survey, which considered closed questions of the dimensions: economic, sociocultural and environmental. Then we made the comparisons between farms, the data obtained for each variable was standardized on a scale of 0 to 4. The value 4 represents the highest sustainability and 0 the lowest sustainability (Table 1). The values obtained for each sub- indicator were weighted multiplying it by a coefficient according to the relative importance of each variable with respect to sustainability. The weighting of sub-indicators and variables was valided with technicians and farmers in the area (Márquez & Julca, 2015). The formulas used to calculate the indicators of sustainability were: Economic indicator (IK) = Ecological indicator (IE) = Sociocultural indicator (ISC) = With economic (IK), environmental (IA) and social (ISC) indicators values found, the general sustainability index (ISGen) was calculated, weighting the three dimensions equally, according to the definition of sustainability. It was considered that to be sustainable a farm must have an ISGen greater to 2 and, in addition, none of the three dimensions individually, should have an indicator with a value less to 2. Figure 1. Location of the Province of Santa Elena in Ecuador Sustainability of lemon (Citrus aurantifolia Swingle) farms in the province of Santa Elena, Ecuador September - December 2018 46 Economic dimensión Profitability of the farm (A) Net income (B) Economic risk (C) Value A1 A2 A3 A4 A5 B C1 C2 C3 4 >20 >60 <5 100 340-350 >610 >4 0-20 4 3 15-20 60-50 5.1-10 75 330-339 550-600 4 21-40 3 2 11-14 45-49 10.1-15 50 320-329 500-549 3 41-60 2 1 9-10 40-44 15.1-25 25 310-319 450-499 2 61-80 1 0 <9 <40 >25 <25 <310 <450 1 81-100 0 Ecological dimensión Soil life conservation (A) Risk of soil erosion (B) Management of the BD (C) Value A1 A2 B1 B2 AZC 4 100 Total 0-5 B2-1 >1 3 75-99 Alta 6-15 B2-2 0.5-1 2 50-74 Media 16-30 B2-3 0.25-0.5 1 25-49 Baja 31-45 B2-4 <0.25 0 <25 MNC >45 B2-5 0 Sociocultural dimensión Value Satisfaction of basic needs (A) Social integration (B) C&CE (C) A1 A2 A3 A4 B C 4 A1-1 A2-1 A3-1 A4-1 Very high C1-1 3 A1-2 A2-2 A3-2 A4-2 High C1-2 2 A1-3 A2-3 A3-3 A4-3 Media C1-3 1 A1-4 A2-4 A3-4 A4-4 Low C1-4 0 A1-5 A2-5 A3-5 A4-5 Null C1-5 Legend: In Economic Dimension: A1: Productivity t ha-1; A2: Physical quality of the lemon (mm); A3: Incidence of pests and diseases (%); A4: Use of rootstock for lemon Subtle (%); A5: Density of plantation (plants ha-1). B: Net income (Dollars); C: Economic risk; C1: Diversification in production (number of products); C2: Dependence of external inputs (%); C3: Numbers of commercialization routes for lemon. In Ecological Dimension: A1: Management of vegetation cover (%); A2: Crop diversification; MNC: Monoculture; B: Risk of soil erosion; B1: Predominant slope (%); B2: Soil conservation; B2-1: Level curves or terraces; B2-2: Live and dead barriers; B2-3: Borderlines; B2-4: Staggered against the slope; B2-5: Sowing in favor of the slope; C: Biodiversity management (BD); AZC: Areas of conservation area (ha). In Sociocultural Dimension: A1: Housing (material); A1-1: Concrete; A1-2: Mixed; A1-3: Wood; A1-4: Reed; A1-5: Do not have your own home. A2: Access to education. A2-1: University or Institute. A2-2: High school. A2-3: Elementary and secondary school. A2-4: Elementary and secondary school. A2-5: Without access to education. A3: Access to health and health coverage. A3-1: Adequate infrastructure and permanence of doctors. A3-2: Medically equipped and temporary doctors. A3-3: Badly equipped and temporary doctors. A3-4: Badly equipped and without qualified personnel. A3-5: Without health center. A4: Basic services. A4-1: Installation of all services. A4-2: Installation of water and energy. A4-3: Installation of light and well water. A4-4: No installation of light and well water. A4-5: Without light and without water. B: Social Integration; C: Ecological knowledge and awareness (C & CE). C1-1: Wide view on ecology, beyond your farm. C1-2: Knowledge of ecology from everyday practice. No use of agrochemicals, conservation practices. C1-3: Partialized view of ecology. Awareness about some practices that affect the environment. C1-4: They do not present an ecological knowledge. But it uses low input practices. C1-5: No kind of ecological awareness. Table 1.- Sub-indicators and indicators used to evaluate the sustainability of lemon producing farms in Santa Elena, Ecuador. The mathematic formula to calculate the ISGen was: General Sustainability Index (ISGen) = The sustainability analysis was carried out individually for the 86 farms. Cluster multivariate analisis technique was used to select four “type farms” and the critical points of the three dimensions of sustainability to be compared were analysed. The “type farms” are those that represent a group of farmers or production systems with similar characteristics (Salazar, 2012; Tuesta et al., 2014; Santistevan et al., 2015; Collantes, 2016). Santistevan-Mendez, M., Borjas-Ventura, R. , Alvarado-Huaman, L. , Anzules-Toala, V., Castro-Cepero, V., Julca-Otiniano, A. Peruvian Journal of Agronomy 2 (3): 44-53 (2018) 47 Table 2.- Most important characteristics of “type farms” producing lemon in Santa Elena, Ecuador (Santistevan et al., 2015). Table 3.- Scores obtained in each of the sub-indicators in the evaluation of the sustainability of lemon producing farms, in Santa Elena, Ecuador. Characteristic Type I Type II Type III Type IV Number of farms (%) 44.6 15.7 26.5 13.3 Average total area of farmland (ha) 2.3 4.3 4.5 16.5 Average area with lemon (ha) 1.2 1.2 2.5 4.5 Average N° plants/ha 250 275 260 280 Investment/ha/year (US$) 325 400 625 1450 Monthly income (US$) 450 540 675 700 Location Manglaralto Colonche Colonche Manglaralto Economic dimension Profitability of the farm (A) Net income (B) Economic risk (C) A1 A2 A3 A4 A5 B C1 C2 C3 Value 1.6 1.9 1.1 3.2 2 0.8 0.8 1.2 0.7 Ecological dimension Soil life conservation (A) Risk of soil erosion (B) Management of the BD (C) A1 A2 B1 B2 AZC Value 1.4 0.6 3.6 3.2 1.6 Sociocultural dimension Satisfaction of basic needs (A) Social integration (B) Knowledge and EC (C) A1 A2 A3 A4 B C Value 3.6 1.8 1.9 2.7 1.4 1.9 Results The lemon farms in Santa Elena can be organized into four groups (Santistevan et al., 2015) and the most important characteristics of the “type farms” of each group are presented in Table 2. Table 3 shows that when assessing economic sustainability, for most variables, lemon farms had average values far from four, ranging from zero to four. For example, in the sub-indicator of profitability sub-indicator (A), the variable Use of rootstock for lemon (A4) had a value close to four, with the mandarin Cleopatra as the most frequent rootstock; the variables A1, A2, A3 and A5 values less than 2. The indicator of Net Income (B) the value was 0.8, i.e. between 200 and 300 US$/month. The sub-indicator Economic Risk (C) has the highest value in Dependence on external inputs (C2=1.2); but in all cases the values were less than two. The economic indicator (IK) was greater than two in only 25.30% of the farms evaluated, a result that indicates that most of the farms were not economically sustainable (Figure 2). Table 3 also presents the results of the ecological sustainability assessment. For the sub-indicator Conservation of soil life (A), variables Management of vegetation cover (A1) and Crop diversification (A2) have values less than two. For Risk of soil erosion (B), subindicators Predominant slope variable (B1) and Soil conservation (B2) haved values greater than two, the farmes use land with slopes less than 5% and the crop is installed using contour lines or terraces, repectively. The Legend: In Economic Dimension: A1: Productivity; A2: Physical quality of the lemon; A3: Incidence of pests and diseases; A4: Use of rootstock for lemon Subtle; A5: Planting density. B: Net income: C1: Diversification in production; C2: Dependence of external inputs; C3: Numbers of commercialization routes for lemon. In Ecological Dimension: A1: Management of vegetation cover; A2: Crop diversification; CD: Monoculture; B1: Predominant slope; B2: Soil conservation. Management of BD: Management of biodiversity. MB: Areas of conservation. In Sociocultural Dimension: A1: Housing (type of material); A2: Access to education; A3: Access to health and health coverage; A4: Basic services; B: Social integration; C: Knowledge and ecological conscience Sustainability of lemon (Citrus aurantifolia Swingle) farms in the province of Santa Elena, Ecuador September - December 2018 48 Biodiversity Management sub-indicator has the variables Areas of Conservation Zones (AZC) with a value less than two. The ecological indicator (IE) is greater than two in the 60.24% of the farms evaluated, a result that indicates that most of the farms are ecologically sustainable (Figure 2). As for socio-cultural sustainability, Table 3 shows that, for most variables, lemon farms had average values of less than four also ranging from zero to four. For the sub- indicator Satisfaction of basic needs (A), both variables Housing material (A1) and Basic services (A4) had values greater than two, i.e. the houses are made of concrete and have water, drainage and telephone installations. The sub- indicator Social Integration (B) had a value less than two and the same was found for the sub-indicator Ecological Knowledge and Awareness (C). The sociocultural indicator (ISC) was greater than two in 55.4% of the farms evaluated, a result that indicates that most of the farms were socioculturally sustainable (Figure 2). In general, 74.7% of the farms evaluated had an ISGen less than 2 (Figure 2), i.e. only 25.3% of lemon farms are currently sustainable. Discussion Dimensions of sustainability Economic sustainability is understood as the set of strategies that allow the agricultural business to remain financially viable over time and provide an acceptable livelihood for the rural family (Lien et al., 2007). In this study, only 25.3% of farms are economically sustainable (Figure 2), while 74.7% do not, because lemon production is affecte by low productivity and low fruit quality. The incidence of pests and diseases is high, and although the use of patterns for lemon cultivation is an adequate and widespread technique among producers in this area, it is not enough to obtain high yields or to improve the quality of lemon (Table 3). The values of productivity and plantation density indicate that there is potential for increasing productivity, with densities of 312 plants ha-1, productivity values of up to 42.1 t ha-1 have been reported (Medina et al., 2004). Likewise, there may be other factors that would affect the production of Citrus aurantifolia such as the inappropriate use of fertilizers, use of unimproved cultivars, lack of weed control and others. This would indicate the need for comprehensive improvement in crop management, including agronomic practices such as pest, disease and weed management (Lardizabal & Medlicott, 2013). The monthly net income is low, below $300, which is related to low productivity and fruit quality. In addition, having only one marketing channel and a high dependence on external inputs shows the high financial risk assumed by lemon farmers in the Santa Elena area. However, Santa Elena farmers have chosen to specialize in this crop; this is probably because the farmer cannot diversify or because alternative crops that can be grown in their area do not have the profitability they seek. A high dependence on external inputs carries a danger for farmers as they can increase in price regardless of the price of the product (in this case the lemon). This would cause an increase in production costs and a crisis of economic resources that would result in this small producer being expelled from the market (Altieri Figure 2. Evaluation of sociocultural sustainability (ISC), ecological (IE), economic (IK) and General Sustainability Index (ISG) of lemon producing farms, in Santa Elena, Ecuador. Santistevan-Mendez, M., Borjas-Ventura, R. , Alvarado-Huaman, L. , Anzules-Toala, V., Castro-Cepero, V., Julca-Otiniano, A. Peruvian Journal of Agronomy 2 (3): 44-53 (2018) 49 & Nicholls, 2010). The low social integration (Table 3) shows that small farmers are not organized, do not have bargaining power and are highly dependent on wholesalers who determine the final price of the product. Ecological sustainability seeks to improve the well- being of the farmer by protecting the resources used to meet human needs and by ensuring that the production of waste does not cause harm to the farmer himself (Goodland, 1995). Only 60.24% of lemon farms are ecologically sustainable, while 39.76% did not reach acceptable levels of sustainability (Figure 2); Producers who achieved positive levels of sustainability implement practices that reduce the risk of soil erosion, such as the use of soils with little slope and soil conservation practices (Table 3). In this regard, Peña et al., 2016; Sanclemente & Patiño, 2015 and Murillo et al., 2016, indicate that the good vegetation cover not only conserves the soil, but also improves its characteristics which in turn can have positive effects on the growth and development of the cultivated plants. Although the implementation of this agricultural practice should be well studied, otherwise it could cause a decrease in crop yields (Salazar et al., 2012). On the other hand, crop diversification not only helps to increase the conservation of tropical soils, but also has an important effect on the biology of soils, favoring the growth and development of different species within the agroecosystem and generating extra income for farmers (Fernández et al., 2015). Work to improve ecological sustainability must be done on the management of low vegetation cover and diversification, for example, with the implementation of other crops or other citrus species as oranges or mandarins. The management of biodiversity on lemon farms can bring great benefits to farmers, such as a decrease in the use of external inputs (Blanco, 2016; Paleologos et al., 2017). Socio-cultural sustainability refers to agriculture that provides meaningful and equitable employment for farmers, workers and their families and produces food for a broad group of consumers (Pilgeram, 2011). In this study, 55.4% of farms are socio-culturally sustainable (Figure 2). In Santa Elena, a majority group of lemon farmers live in houses built with concrete material or are of mixed type, have basic education or have no formal education and the community has a medical center that has neither the adequate infrastructure nor the trained personnel to maintain the health of lemon farmers. On the other hand, the farmers in this area have electricity in their homes and get their water from wells. Various authors use the education factor as a socioeconomic index within sustainable agriculture (Machado & Ríos, 2016) and access to drinking water as a key indicator of environmental sustainability (Fausto & Justo, 2006). Obtaining water from wells can be a risk for the inhabitants of Santa Elena, since it can have high concentrations of microorganisms and other agents harmful to human health (Méndez et al., 2015; Zegarra, 2017), so more in-depth studies are needed on the type of water that is consumed by these populations in order to ensure that it meets all standards for consumption. The low access to education and health services (Table 3), shows that the work of the government in the study area is deficient and that it is necessary to reverse this situation to improve the socio-cultural sustainability of lemon production in this area. While low social integration and ecological knowledge and awareness, suggest the need for greater dissemination of the advantages that have the producer organization and ecological awareness for the improvement of this dimension of sustainability. Critical points of sustainability The concept of sustainability is complex because it implies simultaneously fulfilling several objectives: productives, ecologicals or environmentals, social, culturals, economics and temporal (Sarandón & Flores, 2009). Therefore, the “critical points” can change from one production system to another and it is logical to find some differences between the four types of farms evaluated (Table 2). The analysis of the economic dimension (Figure 3) shows that, in the short term, pest and disease control should be improved, which, added to an increase in plantation density, will have a favorable impact on higher farm productivity and an improvement in the quality of the lemon, which would improve family income. In the medium term, access to new markets should be explored, which would help to improve family income. In the environmental dimension (Figure 3, DA), in the short term, the management of vegetation cover and the increase in the area dedicated to conservation zones could be improved. In the medium term, the task could be achieving a greater diversification of crops, focusing on associated crops accompanied by natural vegetation which would favor the beginning of certification processes for the lemon as organic, sustainable production and others. The certification of agricultural Sustainability of lemon (Citrus aurantifolia Swingle) farms in the province of Santa Elena, Ecuador September - December 2018 50 Figure 3. Critical points of sustainability in the economic (IK), environmental (IE) and sociocultural (ISC) dimensions in “lemon-producing” type farms in Santa Elena, Ecuador. Santistevan-Mendez, M., Borjas-Ventura, R. , Alvarado-Huaman, L. , Anzules-Toala, V., Castro-Cepero, V., Julca-Otiniano, A. Peruvian Journal of Agronomy 2 (3): 44-53 (2018) 51 products allows to enter other types of market that in some cases could mean improvements in price up to 30%. In the analysis of the socio-cultural dimension (Figure 3) the need for improvements in the variables of access to education, social integration and technological knowledge and ecological awareness is evident. Finally, for a farm to be considered sustainable, the General Index (IS Gen) must be greater than two and none of the three indicators must have a value less than two (Sarandón et al., 2006). With these criteria, only 25.3% of lemon farms are currently sustainable. These results show that achieving sustainability of agricultural production systems is a complex task, where improvement is not always the same in each of the three dimensions of sustainability. The results obtained in this study are consistent with other studies carried out in Ecuador in recent years, where sustainability has been evaluated in various agricultural production systems (Santistevan et al., 2015; García, 2015; Palomeque, 2016; Reina, 2016), which suggest a different vision for the future design of agricultural development plans for the country. However, at the present time a low number of sustainable farms is observed, which is mainly explained by the results obtained in the variables related to the economic and socio- cultural dimensions, which shows the low level and quality of life of agricultural producers. Changing this situation is not always in the hands of the farmers because it depends mainly on other instances such as local, regional and national government that must invest in infrastructure and services to improve the competitiveness of this productive sector (Santistevan et al., 2016). Conclusion The majority (74.7%) of the lemon producing farms in Santa Elena (Ecuador) are not sustainable, however adequate techniques are presented such as soil conservation, predominant slope, use of rootstock and planting density that could be replicated in other systems of production. References Altieri, M. & Nicholls, C. (2010). Agroecología: Potenciando la agricultura campesina para revertir el hambre y la inseguridad alimentaria en el mundo. Revista de Economía Crítica, 10, 62-74. http:// revistaeconomiacritica.org/sites/default/files/ revistas/n10/4.pdf Blanco, Y. (2016). El rol de las arvenses como componente en la biodiversidad de los agroecosistemas. Cultivos Tropicales, 37(4), 34-56. http://scielo.sld.cu/pdf/ ctr/v37n4/ctr03416.pdf Collantes, R. (2016). Sustentabilidad de los agro- ecosistemas de palto (Persea americana Mill.) y mandarina (Citrus spp.) en el Valle de Cañete, Lima, Perú. Thesis to opt for the degree of Ph.D. in Agricultura Sustentable, Universidad Nacional Agraria La Molina. UNALM. Perú. 72 pp. García, M. (2015). Ceratitis capitata y la sostenibilidad de Mangifera indica para exportación desde Ecuador. Thesis to opt for the degree of Ph.D. in Agricultura Sustentable. Universidad Nacional Agraria La Molina. UNALM. Perú. 83 p. Gómez-Limón, J. & Arriaza, M. (2011). Evaluación y sustentabilidad de las explotaciones de olivar en Andalucía. Analistas Económicos de Andalucía. Málaga. España. 294 p. Goodland, R. (1995). The concept of environmental sustainability. Annual Review of Ecology and Systematics, 26, 1-24. Fausto, O. & Justo, T. (2006). Acceso al agua potable indicador clave de desarrollo humano. Teoría y Praxis, 2, 171-180. Fernández, I.; Castellanos, L.; Fuentes, M.; Cairo, P.; Rajadel, L. & Prado, R. (2015). Macrofauna del suelo en cuatro fincas de conversión hacia la producción agroecológica en el municipio Cruces. Centro Agrícola, 42(1), 43-52. http://cagricola. u c l v. e d u . c u / d e s c a rg a s / p d f / V 4 2 - N u m e r o _ 1 / cag07115.pdf FAO. (2018). Faostat – Statistics Database. Available in: http://www.fao.org/faostat/en/#data [September 15, 2018] Lardizabal, R. & Medlicott, A. (2013). Planes de manejo Sustainability of lemon (Citrus aurantifolia Swingle) farms in the province of Santa Elena, Ecuador September - December 2018 52 integrado de cultivo. USAID. USA. 186 p. Machado, M. & Ríos, L. (2016). Sostenibilidad en agroecosistemas de café en pequeños productores: revisión sistémica. IDESIA, 34(2), 15-23. http:// dx.doi.org/10.4067/S0718-34292016005000002 Lien, G.; Hardaker, J.B. & Flaten, O. (2007). Risk and economic sustainability of crop farming systems. Agricultural Systems, 94(2), 541-552. https://doi. org/10.1016/j.agsy.2007.01.006 Márquez, F. & Julca, A. (2015). Indicadores para evaluar la sustentabilidad en fincas cafetaleras en Quillabamba. Saber & Hacer, 2(1), 128- 137. http:// revistas.usil.edu.pe/index.php/syh/article/view/45 Medina, V.; Becerra, S. & Ordaz, E. (2004). Crecimiento y rendimiento de limón mexicano en altas densidades de plantación en el trópico. Revista Chapingo Serie Horticultura, 10(1), 43-49. https://www.chapingo. mx/revistas/revistas/articulos/doc/rchshX175.pdf Méndez, R.; Pacheco, J.; Castillo, E.; Cabrera, A.; Vázquez, E. & Cabañas, D. (2015). Calidad microbiológica de pozos de abastecimiento de agua potable en Yucatán, México. Ingeniería, 19(1), 51-61. https:// www.redalyc.org/html/467/46750924005/ Murillo, J.; Méndez, V. & Brenes, S. (2016). Efecto de Geophila macropoda (Rubiaceae) como arvense de cobertura en la erosión hídrica en bananales de Guápiles, Limón, Costa Rica, Cuadernos de Investigación UNED, 8(2), 217-223. http:// www.scielo.sa.cr/pdf/cinn/v8n2/1659-4266- cinn-8-02-00217.pdf Palomeque, M. (2016). Sustentabilidad de Sistemas agrícola de limón (Citrus aurantifolia C.), Cacao (Theobroma cacao L.) y Bambú (Guadua angustifolia K.) en Portoviejo – Ecuador. Thesis to opt for the degree of Doctorado en Agricultura Sustentable, Universidad Nacional Agraria La Molina. Lima. Perú. 120pp. Paleologos, M.; Iermanó, M.; Blandi, M. & Sarandón, S. (2017). Las relaciones ecológicas: un aspecto central en el rediseño de agroecosistemas sustentables, a partir de la Agroecología. Redes, Revista do Desenvolvimiento regional, 22(2), 92- 115. https://online.unisc.br/seer/index.php/redes/ article/view/9346/pdf Peña, K.; Rodríguez, J.; Olivera, D.; Fuentes, P. & Melendrez, J. (2016). Prácticas agrícolas sostenibles que incrementan los rendimientos de diferentes cultivos en Sancti Spíritus, Cuba. Agronomía Costarricense, 40(2), 117-127. https://dx.doi. org/10.15517/rac.v40i2.27391 Pilgeram, R. (2011). The Only Thing That Isn’t Sustainable . . . Is the Farmer: Social Sustainability and the Politics of Class among Pacific Northwest Farmers Engaged in Sustainable Farming. Rural Sociology, 76(3), 375–393 https://onlinelibrary.wiley.com/ doi/abs/10.1111/j.1549-0831.2011.00051.x Proyecto Integral de Desarrollo Agrícola Ambiental y Social de Forma Sostenible en el Ecuador - PIDAASSE. (2011). Resultados Proyecto PIDAASSE, 2010- 2011. Reina, J. (2016). Sustentabilidad de los sistemas Agropecuarios en la zona del proyecto de riego Carrizal-Chone Etapa I (Manabí, Ecuador). Thesis to opt for the degree of Ph.D. en Agricultura Sustentable. Universidad Nacional Agraria La Molina. Lima. Perú. 138 pp. Santistevan, M.; Julca, A. & Helfgott, S. (2015). Caracterización de las fincas productoras del cultivo limón en las localidades de Manglaralto y Colonche (Santa Elena, Ecuador). Revista Científica y Tecnológica UPSE, 3(1), 133-142. Santistevan, M.; Helfgott, S.; Loli, O. & Julca, A. (2017). Comportamiento del cultivo del limón (Citrus aurantifolia Swingle) en “fincas tipo” en Santa Elena, Ecuador. IDESIA (Chile), 35(1), 45-49. https://scielo.conicyt.cl/scielo.php?script=sci_ abstract&pid=S0718-34292017000100008&lng=e s&nrm=iso Santistevan M.; Julca, A. & Borjas, R. (2016). Sustentabilidad de fincas productoras de café en Jipijapa (Manabí, Ecuador). Saber &Hacer, 3(1), 23-25. http://revistas.usil.edu.pe/index.php/syh/ article/view/183 Santistevan-Mendez, M., Borjas-Ventura, R. , Alvarado-Huaman, L. , Anzules-Toala, V., Castro-Cepero, V., Julca-Otiniano, A. Peruvian Journal of Agronomy 2 (3): 44-53 (2018) 53 Salazar, R. (2012). Caracterización de sistemas agroecológicos para el establecimiento comercial de cacao orgánico (Theobroma cacao) en Talamanca. Revista Tecnología en Marcha, 25(5), 45-54. https:// doi.org/10.18845/tm.v25i5.473 Salazar, L.; Arango, J. & Morales, C. (2012). Interferencia de coberturas vegetales en la zona de raíces y de calles del cultivo de café. CENICAFÉ, 63(2), 50-57. http://biblioteca.cenicafe.org/ bitstream/10778/535/1/arc063%2802%2950-57. pdf Sanclemente, O. & Patiño, C. (2015). Efecto de Mucuna pruriens como abono verde y cobertura, sobre algunas propiedades físicas del suelo. Entramado, 21, 206-211. http://www.scielo.org.co/pdf/entra/ v11n1/v11n1a15.pdf Sarandón, S. (2002). El desarrollo y usos de indicadores para evaluar la sustentabilidad de los agroecosistemas. In: Agroecología, el camino hacia una agricultura sustentable. Ed. Científicas Americanas. Chapter 20. Pp 393-414. Sarandón, S.; Zuluaga, S.; Cieza, R.; Gómez, C.; Janjetic, L. & Negrete, E. (2006). Evaluación de la sustentabilidad de sistemas agrícolas de fincas en Misiones, Argentina, mediante el uso de indicadores. Agroecología, 1, 19-28. Sarandón, S. & Flores, C. (2009). Evaluación de la sustentabilidad en agroecosistemas: una propuesta metodológica. Agroecología, 4, 19-28. https:// revistas.um.es/agroecologia/article/view/117131 Scheaffer, R.L.; Mendenhall, W. & Ott, L. (1987). Elementos de muestreo. Grupo editorial Iberoamérica: México. SAMBITO (Soluciones Ambientales Totales). (2014). Estudio De Impacto Ambiental. Aspectos Demográficos. Tuesta, O.; Julca, A.; Borjas, R.; Rodríguez, P. & Santistevan, M. (2014). Tipología de fincas cacaoteras en la subcuenca media del río Huayabamba, distrito de Huicungo (San Martín, Perú). Ecología Aplicada, 13(2), 71-78. http://www.scielo.org.pe/pdf/ecol/ v13n2/a01v13n2 USDA (United States Department of Agriculture). (2018). Citrus: World Markets and Trade. Foreing Agricultural Service. USA. Zegarra, A. (2017). Evaluación de agua no tratada de pozos, en la zona sur de la ciudad de Juliaca, 2017. Revista Científica Investigación Andina, 17(1), 207-216. http://revistas.uancv.edu.pe/index.php/ RCIA/article/viewFile/325/269