• Authors:
    • Pathak,H.
    • Jain,N.
    • Bhatia,A.
  • Source: Web Of Knowledge
  • Volume: 11
  • Issue: 4
  • Year: 2015
  • Summary: Indian agriculture is highly prone to the risks due to climate change caused by increase in the concentration of atmospheric greenhouse gases (GHGs) i.e., carbon dioxide (CO 2), methane (CH 4) and nitrous oxide (N 2O). The recent Assessment Report of the Inter-Governmental Panel on Climate Change (IPCC) reiterated that the warming of the climate system is unequivocal and may intensify in coming decades. Climate change can affect agriculture through direct and indirect effects on the crops, soils, livestock and pests. Development of technologies for adaptation and mitigation and their uptake at speedy rate by the farmers are essential for climate change management. Potential adaptation strategies include developing cultivars tolerant to heat and salinity stress and resistant to flood and drought, modifying crop management practices, improving water management, adopting new farm techniques such as resource conserving technologies (RCTs), crop diversification, improving pest management, better weather forecasts and crop insurance and harnessing the indigenous technical knowledge of farmers. There is a need to develop policy framework for implementing the adaptation and mitigation strategies so that the farmers are saved from the adverse impacts of climate change and the food and nutritional security of the country is ensured.
  • Authors:
    • Cayambe,J.
    • Iglesias,A.
    • de Jalón,S. G.
    • Chuquillanqui,C.
    • Riga,P.
  • Source: ITEA
  • Volume: 111
  • Issue: 2
  • Year: 2015
  • Summary: The temperature rise of the planet associated with anthropogenic greenhouse gas emissions promotes interest for strategies to mitigate them. Since agriculture is a sector responsible for nearly a fifth of global emissions, it is necessary to identify measures to be applied, what is their mitigation potential and the estimated cost of implementing each measure. Our study addresses these questions by comparing the production of potato in two distinct production systems and with actual field data. In a first step, this paper calculates in a modern agricultural system the carbon footprint of mechanization and energy use for irrigation (located in Spain) and in less productive systems that integrate less technologies (located in Peru) . The results show that in the case studies in both countries the nitrogen cycle represents the primary source of greenhouse gas emissions, followed by energy fuel for irrigation and mechanization. Subsequently this study evaluates economically the mitigation actions through Marginal Abatement Cost Curves. These results demonstrate that the management of nitrogen fertilizer is the best alternative to reduce the carbon footprint because of their greater potential to reduce greenhouse gas emissions and their lower equivalent mitigation costs. Finally, the study provides a methodological framework that can be easily applied to other crops. © 2015, Asociacion Interprofesional para el Desarrollo Agrario. All rights reserved.
  • Authors:
    • Salazar,Osvaldo
    • Rojas,Claudia
    • Avendano,Fernando
    • Realini,Piero
    • Najera,Francisco
    • Tapia,Yasna
  • Source: Web Of Knowledge
  • Volume: 102
  • Issue: 3
  • Year: 2015
  • Summary: Vegetated buffer strips (BS) can help prevent nitrogen (N) losses from fields by subsurface lateral flow, thus protecting water resources. The purpose of this study was to determine if narrow BS would effectively remove dissolved inorganic N from subsurface lateral flow. Nitrate-N (NO3-N) and ammonia-N (NH3-N) concentrations in subsurface lateral flow were measured at 1 m depth in a BS system consisting of five treatments: G: strip of grass (Fescue arundinacea); GS: strip of grass and line of native shrubs (Fuchsia magellanica); GST1: strip of grass, line of shrubs and line of native trees 1 (Luma chequen); GST2: strip of grass, line of shrubs and line of native trees 2 (Drimys winteri); and C: bare soil as control. Water samples for the NO3-N and NH3-N measurements were collected between June 2012 and August 2014 in observation wells located at the inlet (input) and outlet (output) of each treatment. The analyses showed that vegetated BS had NO3-N removal efficiency ranging from 33 to 67 % (mean 52 %), with the G treatment showing the best performance in reducing NO3-N concentrations in subsurface lateral flow. The BS treatments were not effective in reducing NH3-N concentrations. The results suggested that N uptake by grass is the main process associated with the NO3-N retention capacity of vegetated BS.
  • Authors:
    • Cisz, M.
    • Galdos, M.
    • Hilbert, J.
    • Rod, K.
    • Ferreira, A.
    • Leite, L.
    • Kaczmarek, D.
    • Chimner, R.
    • Resh, S.
    • Asbjornsen, H.
    • Scott, D.
    • Titus, B.
    • Gollany, H.
  • Source: Environmental Management
  • Volume: 56
  • Issue: 6
  • Year: 2015
  • Summary: Rapid expansion in biomass production for biofuels and bioenergy in the Americas is increasing demand on the ecosystem resources required to sustain soil and site productivity. We review the current state of knowledge and highlight gaps in research on biogeochemical processes and ecosystem sustainability related to biomass production. Biomass production systems incrementally remove greater quantities of organic matter, which in turn affects soil organic matter and associated carbon and nutrient storage (and hence long-term soil productivity) and off-site impacts. While these consequences have been extensively studied for some crops and sites, the ongoing and impending impacts of biomass removal require management strategies for ensuring that soil properties and functions are sustained for all combinations of crops, soils, sites, climates, and management systems, and that impacts of biomass management (including off-site impacts) are environmentally acceptable. In a changing global environment, knowledge of cumulative impacts will also become increasingly important. Long-term experiments are essential for key crops, soils, and management systems because short-term results do not necessarily reflect long-term impacts, although improved modeling capability may help to predict these impacts. Identification and validation of soil sustainability indicators for both site prescriptions and spatial applications would better inform commercial and policy decisions. In an increasingly inter-related but constrained global context, researchers should engage across inter-disciplinary, inter-agency, and international lines to better ensure the long-term soil productivity across a range of scales, from site to landscape.
  • Authors:
    • Gimeno, B. S.
    • Gattinger, A.
    • Lassaletta, L.
    • Aguilera, E.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 168
  • Year: 2013
  • Summary: Mediterranean croplands are seasonally dry agroecosystems with low soil organic carbon (SOC) content and high risk of land degradation and desertification. The increase in SOC is of special interest in these systems, as it can help to build resilience for climate change adaptation while contributing to mitigate global warming through the sequestration of atmospheric carbon (C). We compared SOC change and C sequestration under a number of recommended management practices (RMPs) with neighboring conventional plots under Mediterranean climate (174 data sets from 79 references). The highest response in C sequestration was achieved by those practices applying largest amounts of C inputs (land treatment and organic amendments). Conservation tillage practices (no-tillage and reduced tillage) induced lower effect sizes but significantly promoted C sequestration, whereas no effect and negative net sequestration rates were observed for slurry applications and unfertilized treatments, respectively. Practices combining external organic amendments with cover crops or conservation tillage (combined management practices and organic management) showed very good performance in C sequestration. We studied separately the changes in SOC under organic management, with 80 data sets from 30 references. The results also suggest that the degree of intensification in C input rate is the main driver behind the relative C accumulation in organic treatments. Thus, highest net C sequestration rates were observed in most eco-intensive groups, such as "irrigated", "horticulture" and controlled experiments ("plot scale"). (C) 2013 Elsevier B.V. All rights reserved.
  • Authors:
    • Silva, P.
    • Pino, V.
    • Fuentes, J.-P.
    • Martinez, E.
    • Acevedo, E.
  • Source: Soil and Tillage Research
  • Volume: 126
  • Year: 2013
  • Summary: Soil management practices may change the soil properties. The magnitude of the change varies according to the soil property, the climate, and the type and time of implementation of a particular management system. The aim of this study was to evaluate the effects of no-tillage (NT) on the chemical and biological properties of an Entic Haploxeroll in Central Chile. Soil organic carbon (SOC), microbial biomass and associated indicators q(CO2), q(Mic), q(Min), available N, P and K, pH, electrical conductivity (EC), and crop yield were determined in a field experiment having a wheat (Triticum turgidum L)-maize (Zea mays L.) crop rotation. The change in soil chemical properties was further evaluated using a greenhouse bioassay in which ryegrass (Lolium perenne L) was grown in soil samples extracted at 0-2,2-5, and 5-15 cm depth. After nine years SOC in the NT treatment was 29.7 Mg ha(-1) compared to 24.8 Mg ha(-1) of CT, resulting in 4.98 Mg ha(-1) C gain. The NT therefore resulted in an average annual sequestration of 0.55 Mg C ha(-1) yr(-1) in the upper 15 cm soil. The soil organic C stored under NT was mainly accumulated in the top 2-cm of soil. The biological indicators showed a greater biological soil quality under NT than under CT. Soil organic C was positively associated with available N, P. and K, but negatively with soil pH. The iyegrass bioassay yielded higher biomass in NT than CT. An improvement in the soil chemical quality of the NT soil was considered to be the main reason for this result. The maize yield under NT had the tendency to improve in time as compared to CT. Wheat, however, had lower yield under NT. It was concluded that NT increased C sequestration and SOC improving the chemical and biological properties of this soil. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Rodriguez-Delfin, A.
  • Source: Acta Horticulturae
  • Issue: 947
  • Year: 2012
  • Summary: Hydroponics has been used during years for research in the field of plant mineral nutrition and related topics. Today the soilless culture method is the most intensive horticulture production and is being applied with success in developed countries for commercial purposes. The growing and future of hydroponics in Latin America will much depend of the developing and adaptation of less sophisticated commercial systems. These have to be cost competitive with respect to the high sophisticated technology generated and used in developed countries, using natural and local substrates, developing native or endemic crops of the Region with economical potential for its high feed or medicinal value, among others. Meanwhile, as there is a considerable decreasing of agricultural soils in the world, soilless culture would be an important production alternative in urban and peri-urban areas, mainly in undeveloped countries. Inside the context of urban agriculture, hydroponics could be applied in the cities with more simple and low cost of technologies, mainly in extreme poverty areas, as a way to spread vegetables for self-consumption and to support the family or community income. Also to create micro-companies that will generate employments. There are no official statistics on the evolution of the state of the hydroponic cultures in Latin America. The main hydroponic systems used are the drip irrigation and NFT system. According with their profits, the main hydroponic crops are lettuce, tomato, pepper and strawberry. In Andean countries like Peru, Bolivia, Colombia and Ecuador, aeroponics is being developing to obtain basic potato tuber seed, free of virus. In relation to the media used in soilless culture, there is no ideal or optimum substrate, because a great diversity in media could be used, as pure or as mix form. Among the inorganic substrates it is possible to use quarry, river and quartz sand, gravel, pumice and tezontle. Husk rice, coco fiber, peat moss and sawdust are used as organic media. The use of rock wool is not generalized in the Region, but in countries like Mexico and Chile it is mainly used in tomato crop with drip irrigation system. Brazil and Mexico are the more representative hydroponic countries in Latin America. The area of soilless culture is increasing in the Region and every day there is much interest to learn and to dominate this technique of plants production without using soil. A great number of international courses, seminaries, congresses and symposia organized in countries like Peru, Mexico, Brazil, Costa Rica and Chile demonstrate this affirmation. Finally, it is necessary to obtain a hydroponic certification, as well as the organic products, to support the hydroponic growers in our countries.
  • Authors:
    • Pozo, A. del
    • Martinez G.,I.
    • Prat, C.
    • Uribe, H.
    • Valderrama V., N.
    • Zagal, E.
    • Sandoval, M.
    • Fernandez, F.
    • Ovalle, C.
  • Source: Chilean Journal of Agricultural Research
  • Volume: 71
  • Issue: 4
  • Year: 2011
  • Summary: Chilean dryland areas of the Mediterranean climate region are characterized by highly degraded and compacted soils, which require the use of conservation tillage systems to mitigate water erosion as well as to improve soil water storage. An oat ( Avena sativa L. cv. Supernova-INIA) - wheat ( Triticum aestivum L. cv. Pandora-INIA) crop rotation was established under the following conservation systems: no tillage (Nt), Nt+contour plowing (Nt+Cp), Nt+barrier hedge (Nt+Bh), and Nt+subsoiling (Nt+Sb), compared to conventional tillage (Ct) to evaluate their influence on soil water content (SWC) in the profile (10 to 110 cm depth), the soil compaction and their interaction with the crop yield. Experimental plots were established in 2007 and lasted 3 yr till 2009 in a compacted Alfisol. At the end of the growing seasons, SWC was reduced by 44 to 51% in conservation tillage systems and 60% in Ct. Soil water content had a significant (p<0.05) interaction with tillage system and depth; Nt+Sb showed lower SWC between 10 to 30 cm, but higher and similar to the rest between 50 to 110 cm except for Ct. Although, SWC was higher in conservation tillage systems, the high values on soil compaction affected yield. No tillage+subsoiling reduced soil compaction and had a significant increment of grain yield (similar to Ct in seasons 2008 and 2009). These findings show us that the choice of conservation tillage in compacted soils of the Mediterranean region needs to improve soil structure to obtain higher yields and increment SWC.
  • Authors:
    • Ortega-Farias, S.
    • Selles, G.
  • Source: ISHS Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: These proceedings contain 79 papers on irrigation systems for horticultural crops. Specific topics covered include the following: improvement of water use for agriculture at catchment level under drought conditions; impact of climatic change on irrigated fruit tree production; effects of the irrigation regime and partial root zone drying on grape cv. Vermentino in Sardinia, Italy; effects of canopy exposure changes on plant water status in grape cv. Syrah; water use by drip-irrigated early-season peach trees; soil water content variations as water stress indicator in peach trees; reduction in the number of fruits in peach (T204) due to postharvest deficit irrigation; effects of irrigation management and N fertilizer on the yield and quality of apple cv. Gala; canopy temperature as an indicator of water status in citrus trees; effects of root anatomy on sap flow rate in avocado trees; influence of rootstock on the response of avocado cv. Hass to flooding stress; methods of selection for drought tolerance in potato; and drip irrigation for the establishment of strawberry transplants in southern California.
  • Authors:
    • Rypowski, K.
    • Cortes, M.
    • Osorio, A.
    • Burgos, M.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: Six tests were done to evaluate the application of irrigation rates in Limari River Valley (3036′ South Latitude 7112′ West Longitude and 218 m of altitude) in avocado and mandarin tree orchards during two agricultural seasons. Assessments were made in volumes of water applied, discharge of the drippers and irrigation frequency used. Also, the water stored in the soil profile was monitored by moisture direct sampling with drill, performed deeply and transversely to the drip lines and plantation rows. In the cases studied it was possible to appreciate a wide variety of situations regarding water stored in the profile. In the vast majority of cases, excess water conditions were found, both in the root zone and below it. In very few cases, the moisture in the root zone of trees reached levels close to permanent wilting percentage (PWP). This would reflect poor efficiency in the implementation and management of irrigation water through drip irrigation, regardless of the uniformity coefficient (UC) of drippers. This situation becomes much more problematic in those soils which present high percentages of clay; creating low aeration conditions for root development. It is also possible to observe an important deviation from moisture profiles to the lower or steeper sectors of the plantation system; generating drier soil or less humid conditions in higher zones, with a big impact on root development. When calculating the relation between the water stored in the root zone versus the total water available in the profile, results between 44 and 73% were obtained, values that reflect inefficient irrigation conditions. These results were corroborated by the high variation coefficients (VC) in the moisture content in the profile, with values higher than 19.00% and with maximum value equal to 43.64% VC.