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[en] The efficacy of soil biosolarization for the control of Verticillium dahliae and Rhizoctonia solani fungal pathogens was evaluated over two consecutive artichoke crop cycles in southeastern Spain. Soil biosolarization was applied in mid-June for 42 days. The evaluated soil treatments were: fresh sheep manure (FSM); beer bagasse (BB) plus FSM; broccoli crop residues plus FSM; and a control of non-disinfestated and non-amended soil. Different variables were analyzed: i) soil temperature during biosolarization; ii) soil inoculum density of Verticillium before and after biosolarization; iii) infectivity of V. dahliae and R. solani introduced inoculum after biosolarization treatments at 15 and 30 cm soil depth through bioassays; iv) crop disease incidence; and vi) marketable yield. Treatments were randomized in a complete block design with four replicates. Biosolarization treatments reduced levels of both fungal pathogens in both years and had significant lower percentages of affected plants at the end of the crop. All biosolarization treatments significantly improved marketable yield 22-29% to 38-59% compared to the non-disinfestated control in 2015-2016 and 2016-2017 crop cycles respectively. Biosolarization with different organic amendments can be recommended as an effective management strategy for the control of soil-borne fungal diseases in artichoke crops in southeastern Spain, especially in repeated monocultures which are cultivated intensively.
[en] In late 1998, FAO launched a Technical Co-operation Project to assist the government of the Ivory Coast in rural development by promoting agricultural production as the main source of economic growth, and by improving the management of natural resources. The sustainable development of the humid-savannah region and western highlands is being allotted primary consideration. The goal of the project is to replace traditional shifting cultivation with more-sustainable production systems. This paper describes the origins and scope of the problem and the research strategies being considered and employed. The project will be executed in three phases: constraint analysis and formulation of a pilot project, execution of the pilot project (1999-2003), and long-term extension (15 years) from 2004, based on the data generated in the pilot phase. (author)
[en] Aim of the study: To investigate terrestrial bryophyte and lichen species richness and environmental factors affecting the composition of species. Area of the study: Four Boreal zone fixed dunes were selected in the coastal area of the Baltic Sea in southwest Estonia. Material and methods: Non-metric multidimensional scaling was performed to analyse distribution patterns and environmental factors like canopy cover, photosynthetically active radiation, soil organic horizon thickness and decomposition rates, soil volumetric water content, soil pH and electrical conductivity and soil nutrients correlated with bryophyte and lichen species composition. Main results: Thirty bryophytes and 22 lichens were found on 232 sample plots, the most frequent species were Pleurozium schreberi (Willd. ex Brid.) Mitt., Hylocomium splendens (Hedw.) Schimp., Dicranum polysetum Sw. ex anon., Cladonia arbuscula (Wallr.) Flot. and Cladonia furcata (Huds.) Schrad. The lichen species richness was highest on the slopes of the dunes and decreased towards the bottoms and tops; bryophyte species richness was higher on the bottoms and decreased towards the tops of the dunes. Research highlights: The composition of bryophytes and lichens is significantly influenced by the aspect and the location on the dune, light conditions, soil pH, soil salinity (measured as electrical conductivity) and volumetric water content, thickness of moderately decomposed organic horizon and vascular plant species cover.
[en] This work identifies and establishes the concentration of some minerals nutrients in Mata Atlantica and Vale do Aco Eucalyptus (Minas Gerais State, Brazil) soils. The k0 method of analysis with neutron activation and X-ray fluorescence were used. Reference material were used to check the accuracy of the analytical results. The k0 method is being introduced in CDTN using the CDTN/CNEN-B H IPR-R1 TRIGA Mark I reactor. (author). 5 refs., 2 tabs
[en] The choice of a pesticide fate model at field scale is linked to the available input data. The article describes the available pesticide fate models at a field scale and the guidelines for the choice of the suitable model as function of the data input requested
[it]La scelta del giusto modello per la simulazione del destino degli agrofarmaci a scala di campo e cruciale per una serie di motivi legati sia al giusto utilizzo delle informazioni disponibili (input) sia all'attendibilita dei risultati ottenuti. Il presente articolo descrive i modelli disponibili per la simulazione del destino degli agrofarmaci a scala di campo e le linee guida per la scelta di uno di essi
[en] The IBSRAM ASIALAND Management of Acid Soils network aims to improve the understanding of the broad range of biophysical and socio-economic production limitations on infertile acid soils of Southeast Asia, and to lead to development and implementation of sustainable land-management strategies for these important marginal areas. The main activities of the network are in Indonesia, Myanmar, Philippines, and Vietnam, with associated activity in Thailand, and minor involvement in Brunei, Cambodia, Laos, and Malaysia. The main experimental focus is through researcher-managed on-farm trials, to improve the management of phosphorus nutrition with inorganic and organic amendments. A generic design is used across the eight well characterised sites that form the core of the network. The results will be analysed across time and across sites. Improved methods for laboratory analyses, experimental management, socio-economic data collection, and data analysis and interpretation are critical components. Three important initiatives are associated with the core activities. These aim to establish a broader network on maintenance of quality laboratory analyses, to assess the potential for implementation of improved strategies through farmer-managed on-farm trials, and to improve our understanding of, and ways of estimating, nutrient budgets for diverse farming systems. (author)
[en] Soil degradation affects negatively his functions as a base to produce food, to regulate the hydrological cycle and the environmental quality. All over the world soil degradation is increasing partly due to lacks or deficiencies in the evaluations of the processes and causes of this degradation on each specific situation. The processes of soil physical degradation are manifested through several problems as compaction, runoff, hydric and Eolic erosion, landslides with collateral effects in situ and in the distance, often with disastrous consequences as foods, landslides, sedimentations, droughts, etc. These processes are frequently associated to unfavorable changes into the hydrologic processes responsible of the water balance and soil hydric regimes, mainly derived to soil use changes and different management practices and climatic changes. The evaluation of these processes using simple simulation models; under several scenarios of climatic change, soil properties and land use and management; would allow to predict the occurrence of this disastrous processes and consequently to select and apply the appropriate practices of soil conservation to eliminate or reduce their effects. This simulation models require, as base, detailed climatic information and hydrologic soil properties data. Despite of the existence of methodologies and commercial equipment (each time more sophisticated and precise) to measure the different physical and hydrological soil properties related with degradation processes, most of them are only applicable under really specific or laboratory conditions. Often indirect methodologies are used, based on relations or empiric indexes without an adequate validation, that often lead to expensive mistakes on the evaluation of soil degradation processes and their effects on natural disasters. It could be preferred simple field methodologies, direct and adaptable to different soil types and climates and to the sample size and the spatial variability of the hydraulic properties, evaluable at field. It is proposed a model system, based on hydrological processes, properly evaluated with adequate methodologies for each combination of soil, topography, climate and management system. This model has been proved to evaluate the causes and effects of soil and water degradation under different conditions.
[en] Aim of study: To derive mathematical formulas to determine the optimum amounts of applied water and N at variable crop prices and rainfall conditions for sugar beet. Area of study: Karaj Research Center, Alborz Province, Iran. Material and methods: At first, mathematical formulas were derived to determine optimum applied water and nitrogen for sugar beet under rainfall occurrence, land limited (in cases that arable land area is limited and the farmer can not put more land area under irrigation) and water limited conditions when crop price depends on sugar content. Second, this theory was applied to analyze the relevant experimental data. The experiment was a split-plot design with irrigation treatments as the main plots (40%, 80%, 120% and 160% of evaporation from the surface of class A evaporation pan) and N fertilizer rates (0, 90, 180 and 270 kg N/ha) as subplots. Main results: Under land and water limiting conditions, deficit irrigation of 27% and 48% led to 6.4% and 25.4% decrease in yield and 21.4% and 96.2% increase in total net income, respectively, compared with full irrigation. Under water limiting conditions, cultivated land area increased by 93.7, 108 and 128% for 0, 60 and 120 mm rainfall, respectively. Under land limiting conditions, amounts of optimum irrigation water were 12381.2, 11781.2 and 11181.2 m3/ha, for 0, 60 and 120 mm rainfalls, respectively. The corresponding values for N were 262.5 kg/ha in all three rainfall quantities. Besides, under water limiting conditions, optimum amounts of irrigation water were 8708.1, 7828.8 and 6882.1 m3/ha for 0, 60 and 120 mm rainfalls, respectively. The corresponding values for N were 301.1, 299.5 and 295.5 kg/ha, respectively. Optimum amounts of irrigation water and N decreased by increase in rainfall amount. Research highlights: Under limited irrigation water conditions, if the rainfall, residual N, water cost and base crop price increases, the value of optimum applied water should be decreased.
[en] Despite of the fact that many soil erosion models have been developed in the past more than 5 decades including empirical based models like USLE and RUSLE and many process based soil erosion and sediment transport models like WEPP, EUROSEM and SHETRAN, the application of these models to regional scales remained questionable. To address the problem, a process-based soil erosion and sediment transport model has been developed to estimate the soil erosion, deposition, transport and sediment yield at regional scale. The soil erosion processes are modeled as the detachment of soil by the raindrop impact over the entire grid and detachment of soil due to overland flow only within the equivalent channels, whereas sediment is routed to the forward grid considering the transport capacity of the flow. The loss of heterogeneity in the spatial information of the topography due to slope averaging effect is reproduced by adapting a Fractal analysis approach. The model has been calibrated for Nan river basin (N.13A) and validated to the Yom river basin (Y.6) and Nam Mae Klang river basin (P.24A) of Thailand, simulated results show good agreements with the observed sediment discharge data. The developed model with few new components can also be applied for predicting the sediment discharges of the river Indus. (author)