1,721,139 research outputs found

    Salt concentration of The Nutrient Solution: Effects on Transpiration Rate of Soilless Colture

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    Main objective of the study was to verify the possibility of testing salt concentration effects on transpiration rate over an entire cycle of a crop, by using hydroponic lysimeters. The experiment was carried out in North - West of Sardinia (Italy). In 1996, nine hydroponic cropping units (CU) were used to measure transpired water and cotton (Gossypium hirsutum cv. ‘Ogosto’) was utilized as test crop. Three salt concentration levels were obtained adding seawater to the nutrient solution: control (0% of seawater, EC 3.0 mS cm-1, pH 7.1), S8 (8% of seawater, EC 7.7 mS cm-1, pH 6.7) and S16 (16% of seawater, EC 11.5 mS cm-1, pH 6.4). Results indicate that cotton plants are able to develop and produce with 8% of added seawater without differences with control treatment, as previously assessed by other authors. High level of salt concentration reduced plant growth and productivity and increased TAF (transpiration per unit of leaf area, mm d-1). The hydroponic lysimetric system proved to be an effective tool to study the effects of water salinity on water transpiration per unit of leaf area during the whole crop cycle and hence to distinguish the effects of salinity on plant development from the effects on leaf transpiration

    Roots system development in flooded and sprinkler irrigated rice cultivars

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    One of the most important factors to obtain high yield is a good root system development. The exploration of a greater soil mass allows a higher water and nutrient uptake and increases crop yield. Numerous authors noticed a significant correlation between yield and root system dimension. The growing environment, and therefore the agronomic technique, affect root system development. Traditionally rice is grown by flooded irrigation that, due to oxygen lack in deep soil layers, brings to a low root system deepening. In upland rice, where the growing does not take place with continuous flooding, some authors noticed a good root system development. A comparison trial, with national and selected for upland conditions rice cultivars, was carried out to evaluate root system development adopting both traditional flooded irrigation and sprinkler irrigation. Root density was determined by Newman method for different soil depths. Results highlight a greater root density in flooded crop in comparison to sprinkler irrigation. The higher yield obtained with sprinkler irrigation, even higher than flooding irrigation, suggest a greater efficiency of the root system in water and nutrient uptake in oxidized environment
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