The aquifer over exploitation in the central and northern part of Mexico requires efficient strategies in the application, savings, and conservation of water (blue gold) for the sustainability of horticultural crops like apple. So, the objective of this study was to compare the commercial irrigation (CI) with partial rootzone drying (PRD) in relation to the yield and fruit quality at harvest, and water productivity (WP). Emphasis was placed on water productivity, water relationships, tree nutrition, and postharvest performance of fruit. The treatments were: CI as control and PRD. Water productivity was significantly improved by the use of PRD and resulted in a water savings of 2.9 megalitres of water per hectare. Yield, yield components, vegetative growth, fruit size, and fruit quality were not modified by the irrigation treatments. Pruning weight was the lowest in PRD trees. Tree water status, stomatal conductance, and transpiration were lower in PRD trees than in RC trees. Except for calcium and boron, the concentration of the remainder nutrients was similar between treatments. After 18-day in storage, fruit quality was the same between treatments, but fruit water loss tended to increase in PRD fruit. In conclusion, PRD is a water-saving irrigation strategy for the sustainable apple production, mainly for areas where water resource is limited. | La sobre explotación de los acuíferos en el centro y norte de México requiere estrategias eficientes en la aplicación, ahorro y conservación del agua (oro azul) para la sustentabilidad de los cultivos hortícolas como el manzano. Así, el objetivo de este estudio fue comparar el riego comercial (RC) con el riego parcial de la raíz (RPR) en relación al rendimiento y calidad del fruto a la cosecha. Se hizo énfasis en la productividad del agua (PA), en las relaciones hídricas, nutrición del árbol y en el comportamiento del fruto en postcosecha. Los tratamientos fueron: RC como testigo y el RPR. La PA se mejoró significativamente por el uso del RPR y resultó en un ahorro de 2.9 megalitros de agua de riego por hectárea. El rendimiento, componentes del rendimiento, crecimiento vegetativo, tamaño y calidad de la fruta a la cosecha no fueron modificados por los tratamientos de riego. La madera podada fue menor en árboles con RPR. El potencial hídrico, conductancia estomática y transpiración fueron menores en árboles con RPR que en árboles con RC. Excepto por calcio y boro, la concentración del resto de los nutrimentos fue similar entre tratamientos. Después de 18 días en almacenamiento, la calidad de la fruta fue igual entre tratamientos, pero la pérdida de peso de la fruta tendió a incrementarse en la fruta con RPR. En conclusión, el RPR es una estrategia de ahorro de agua de riego para la producción sustentable en manzano, principalmente para regiones donde el recurso hídrico es limitado.

El trabajo se desarrolló en la microcuenca del río Gaira, ubicada en la reserva de Biosfera Sierra Nevada de Santa Marta sobre el mar caribe Colombiano, con el fin de caracterizar la composición florísticas del bosque ribereño, determinar su calidad del agua con base en parámetros físico-químicos, y biológicos como los macroinvertebrados acuáticos, además de adelantar el primer estudio del uso del suelo y determinar algunas características morfométricas de la cuenca y un análisis de paisaje.El análisis de paisaje evidenció una alta fragmentación del bosque ribereño, por su alto número de parches con respecto al área que esta categoría de bosque ocupa en la microcuenca. Lo cual sugiere que es urgente iniciar trabajos de restauración para este tipo de vegetación, conforme a los beneficios ecológicos, ecosistémicos, ecoturísticos, y de zonas amortiguadoras a la fuente hídrica respecto a los usos del suelo que en la microcuenca se presentan.This work was done in Gaira River Basin, located in the biosphere reserve Sierra Nevada de Santa Marta on the Colombian Caribbean, in order to characterize the floristic composition of riparian forest, determine water quality parameters based on physical-chemical, and biological as the aquatic macroinvertebrados. A survey of land use was done in order to determine some morphometric characteristics of the watershed and landscape analysis. The landscape analysis showed a highly fragmented of the riparian forest, by a high number of patches over the area of forest that this category occupies in the microbasin. This suggests that it is urgent restoration work to star this type of vegetation, according to environmental, ecosistems, ecotourism, and buffer zones to the water source on land use watershed are presented. | Tesis (Mag.Sc.) - CATIE, Turrialba (Costa Rica), 2009

O recente crescimento da economia brasileira e as perspectivas mostradas pelos principais indicadores econômicos de que esse crescimento deve se manter e, até se elevar pelos próximos anos levou o sistema de geração e abastecimento de energia elétrica brasileiro a promover e estimular o uso racional e mais eficiente da energia elétrica no país. Como forma de tentar eficientizar e racionalizar o uso da energia elétrica, pode-se citar a tarifa de incentivo para irrigação noturna, com descontos no preço da energia utilizada no período noturno pré-estabelecido e a taxa devida ao uso de energia elétrica com fator de potência abaixo de um limite estabelecido por cada empresa fornecedora de energia. Por meio do uso do inversor de freqüência, pôde–se simular um sistema de abastecimento de água a fim de se racionalizar o uso de energia elétrica. A fim de se realizar uma economia de energia elétrica por meio da eficientização do seu uso com controle de fator de potência e aumentando o rendimento do motor elétrico de acionamento da carga, no caso bomba centrífuga. | The recent growth of the Brazilian economy and the perspectives shown by the main economical indicators that growth owes if to maintain and, until rising for next years it took the generation system and Brazilian electric power provisioning to promote and to stimulate the rational and more efficient use of the electric power in the country. As form of trying to win efficiency and to rationalize the use of the electric power the incentive tariff can be mentioned for nocturnal irrigation, with discounts in the price of the energy used in the pre-established night period and the due tax to the electric power use with potency factor below an established limit for each supplying company of energy. Through the use of the frequency inverter system of water supply could be simulated in order to if it rationalizes the electric power use. In order to take place an electric power economy through the best efficiency with control of potency factor and increasing the income of the electric motor of drive of the load, in the case centrifugal pump.

No presente trabalho objetivou-se avaliar os efeitos da aplicação da água residuária da suinocultura após filtragem (ARSF) nos parâmetros de qualidade de frutos de tomate de mesa. Para isso, tomateiros da variedade Fanny TY foram cultivados em lisímetros de drenagem sob ambiente protegido e fertirrigados com diferentes lâminas de ARSF, com e sem complementação da adubação. Os resultados permitiram concluir que a aplicação de ARSF não alterou as características de qualidade dos frutos de tomate e, para quaisquer lâminas aplicadas, resultou em frutos saborosos e saudáveis. | This study was done to evaluate the use of filtered swine wastewater (FSW) on the quality parameters of table tomato fruits. The tomato cultivar ‘Fanny TY’ was grown in drainage lysimeters in a greenhouse and fertirrigated with different doses of FSW, with and without fertilizer supplementation. The results showed that FSW application at any dose did not alter fruit quality, producing flavored and healthy fruits.

The Priestley-Taylor (PT) model was evaluated for estimating the real evapotranspiration (ETreal) of a drip-irrigated greenhouse tomato (Lycopersicon esculentum Mill.) crop. The net radiation incorporated in the PT model was estimated using meteorological variables. For this experiment, an automatic weather station (AWS) was installed inside the greenhouse to measure solar radiation (Rgi), net radiation (Rn), air temperature (Ta) and relative humidity (RH). Another AWS was installed over a grass cover to measure atmospheric conditions outside the greenhouse. The experiment was carried out at the Panguilemo experimental station (35°23' S, 71°40' W, 110 m.a.s.l.) from August to December 2000. The PT model was evaluated using the ETreal obtained from the water balance (WB) method. In this case, values of ETreal by PT model were calculated using: a) Rgi and soil heat flux (G) = 0; b) Rgi and G ≠ 0; c) solar radiation measured outside the greenhouse (Rge) and G = 0; and d) Rge and G ≠ 0. For these cases, results indicated that PT model was able to compute ETreal with errors less than 5%. Also, Rn was calculated with a relative absolute error and a mean deviation lower than 6% and 0.07 mm d-1, respectively, using Rgi or Rge. Daily soil heat flux values equal to zero did not affect the calculation of ETreal values. Thus, the PT model evaluated in this study could be used for scheduling irrigation for a greenhouse tomato crop, using internal measurements of air temperature and relative humidity, and external measurements of solar radiation. In this case, PT model predicted the ETreal with an error of 6.1%. | Se evaluó el comportamiento del modelo de Priestley-Taylor (PT) para la estimación de la evapotranspiración real (ETreal) de un cultivo de tomates (Lycopersicon esculentum Mill.) en condiciones de invernadero. La radiación neta incorporada en el modelo de PT fue calculada usando variables meteorológicas clásicas. Para este experimento, una estación meteorológica automática (AWS) fue instalada dentro del invernadero para medir radiación solar (Rgi), radiación neta (Rn), temperatura del aire (Ta) y humedad relativa (RH). Una segunda AWS fue establecida sobre una cubierta herbácea para medir las condiciones atmosféricas al exterior del invernadero. El experimento se condujo en la Estación Experimental Panguilemo (35°23’ S, 71°40’ O, 110 m.s.n.m.) durante los meses de agosto a diciembre del 2000. Las estimaciones de ETreal obtenidas por el modelo PT fueron comparadas con los valores calculados por el método del balance hídrico (WB). En este estudio los valores de ETreal obtenidos por PT fueron calculados usando: a) Rgi y flujo de calor del suelo (G) = 0; b) Rgi y G ≠ 0; c) radiación solar medida al exterior del invernadero (Rge) y G = 0; y d) Rge y G ≠ 0. Para estos casos los resultados indicaron que el modelo de PT fue capaz de estimar del tomate con errores menores que un 5%. Asimismo, la Rn fue calculada con un error absoluto relativo y una desviación media de no más del 6% y 0,07 mm d-1, respectivamente, ya sea utilizando Rgi o Rge. La utilización de un valor igual a cero para valores diarios de flujo de calor del suelo no afectó el cálculo de los valores de ETreal. Así, el modelo de PT evaluado en esta investigación podría ser usado para programar el riego de un cultivo de tomates bajo invernadero usando mediciones internas de temperatura y humedad relativa, y mediciones externas de radiación solar. En este caso, el modelo de PT predijo la ETreal con un error de un 6,1%.

Se estimó el secuestro de carbono y uso de agua en seis sistemas silvopastoriles basados en la combinación de Brachiaria brizantha e Hyparrhenia rufa con especies maderables nativas en el trópico seco. Se empleó un diseño experimental de bloques completos al azar con parcelas divididas, donde las pasturas (B. brizantha e H. rufa) fueron las parcelas principales y los maderables (Dalbergia retusa, Dyphisa robinioides y Pithecellobium saman) las subparcelas. Se evaluó el carbono total en la biomasa aérea (árbol y pastura) y debajo del suelo (suelo y raíces), y la transpiración arbórea mediante el método de "flujo de savia" usando 18 individuos (3 repeticiones por especie arbórea por pastura). El mayor almacenamiento de carbono en la biomasa aérea la realizó D. robinoides (4,4 t C/ha), y en la pastura, B. brizantha con P. saman (5,8 t C/ ha). La mayor acumulación de C en raíces finas (d 2 mm) se encontró en los primeros 20 cm del suelo. La mayor cantidad de carbono en raíces se encontró en árboles que crecieron con B. brizantha (1,1 t C/ha) y en pasturas que crecen con la asociación B. brizantha y D. robinioides (1,5 t C/ha). El 55% de C en el suelo se encontró en los primeros 20 cm. La mayor transpiración se encontró en D. robinioides (1,5 mm/día) y la menor, en P. saman (0,3 mm/día). Los sistemas silvopastoriles evaluados resultaron promisorios gracias a su alto secuestro de carbono y su uso de especies maderables con alta eficiencia de uso de agua. Palabras clave: transpiración, biota, flujo de savia, biomasa aérea, biomasa debajo del suelo. | The carbon sequestration and water use of silvopastoral systems with native timber tree species in the dry tropics were estimated. It was used an experimental design of randomly complete blocks with split plots, where grasses (Brachiaria brizantha and Hyparrhenia rufa) were the main plots and timber species (Dalbergia retusa, Dyphisa robinioides y Pithecellobium saman) were the subplots. The total C in aboveground biomass (grasses and trees), belowground C (fine roots and soil) and tree transpiration, using sapflow approach in 18 individuals (three repetitions per tree species per grass) were evaluated. The highest C storage in aboveground biomass was found in D. robinoides with 4.4 t C/ha; in C in grass was found in B. brizantha with P. saman (5.8 t C/ ha). The highest C accumulation in fine roots (d 2 mm) was found in the 20 cm of top soil. Tree growing with con B. brizantha presented the highest C in roots (1.1 t C/ ha); whereas the highest C in grass fine roots was located in B. brizantha with D. robinioides (1.5 t C/ha). Around 55% of soil C was in first 20 cm of soil. The highest and lowest tree transpiration was presented in D. robinioides and P. saman, respectively (1.5 vs 0.3 mm/day). The evaluated silvopastoral systems are promissory due their high C sequestration and the use of timber tree species with high water use efficiency. Keywords: Transpiration, biota, sapflow, aboveground biomass, underground biomass.

Este trabalho objetivou analisar a alocação dos custos de melhorias em bacia hidrográficas entre os diferentes demandantes de água. Tomou-se como exemplo a bacia do rio Paraíba do Sul, localizada nos estados de Minas Gerais, São Paulo e Rio de Janeiro, e utilizaram-se, como critérios de alocação de custos, os volumes de água captada e consumida, além da quantidade lançada de efluentes. A metodologia utilizada consistiu da regra de alocação conhecida como valor de Shapley, pertencente ao ramo cooperativo da teoria dos jogos. No caso da bacia do rio Paraíba do Sul, os valores encontrados indicaram que os usuários urbanos deveriam arcar com a maior parte dos custos, já que este é o setor que mais lança efluentes, sendo a deterioração da qualidade da água um problema importante nesta bacia. | The objective of this work was to analyze the cost allocation of improvements in river basins among the water users. It was used, as example, the Paraíba do Sul river basin, located in the states of Minas Gerais, São Paulo and Rio de Janeiro, and, as criteria of allocation of costs, they were used the volumes of water extracted and consumed, and the quantity of pollutants deposited in the basin area by water users. The methodology used consists of the rule of allocation known as Shapley value, which belongs to the cooperative branch of game theory. In the case of Paraíba do Sul river basin, the values found indicated that the urban users should pay the higher part of the costs of improvements, given that these users are responsible for most of the pollution in the basin area, being the reduction of water quality an important problem in this basin.