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To study the combined effects of controlled water and nitrogen supplies on growth and yield of spring wheat (Triticum aestivum L.), plants were grown in a controlled environment chamber during the entire growth period.When the 3rd leaf was visible, three levels each of water and nitrogen supply, for a total of nine treatments, were applied using the system to accurately control soil water and nitrogen levels. There was a significant interaction of water and nitrogen levels on growth and yield of wheat. Under low water conditions few tillers were produced and the biomass production and grain yield were suppressed, whereas nitrogen supply level had little impact on the plants. With increasing water supply, on the other hand, the production of tillers, biomass and yield increased significantly. Furthermore, the nitrogen supply level had significant effects on growth and yield as the water stress decreased. Water and nitrogen shortages caused increases in phyllochron values. However, heading of the main stem was almost unchanged because of the compensation by a decreased number of leaves on main stem. The impact of water and nitrogen stresses on growth and yield was reflected primarily by the strong response of tillering at the individual plant level.

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This paper presents the successful implementation of logging-while-drilling (LWD) nuclear magnetic resonance (NMR) source-less and lithology-independent technology to place an extended horizontal drain in best porous zone of a challenging, highly heterogeneous thin layer of carbonate rocks. The technology enables this goal by providing advanced formation evaluation and characterization. The objective was to drill a 3000-ft horizontal drain, targeting two stepped down porous units with a net thickness ranging from 6 to 9 ft, a porosity of 3 to 20 %, and a permeability range of 4 to 20 mD. To compare NMR porosity measurement and derived density/neutron porosity in a reference well, a combined bottom hole assembly was designed with density-neutron and NMR along with resistivity and gamma ray instruments to simultaneously log the reservoir. The NMR permeability index was calibrated using parameters developed by integrating the LWD-NMR results with core/mobility data. The generated relationship was then applied to calculate rock properties in wells with LWD-NMR, targeting the same reservoir in this field. The LWD-NMR porosity played an important role in real-time confirmation of well placement within the best porous zones. In addition, the instruments performed reservoir characterization such as porosity distribution (total, movable and bound) and permeability index derivation along the horizontal drain. The LWD-NMR results, porosity and calibrated permeability were used to identify reservoir flow units by applying a Modified Lorenz Plot, which resulted in identifying best producible flow units zones for well completion. Based on a consistent correlation between the neutron density-derived porosity and the NMR measured porosity achieved in the studied wells, NMR combined with resistivity and gamma-ray was a solution for geosteering. This combination also resulted in rig-time savings, and it eliminated risks associated with drilling using radioactive sources and formation evaluation rock properties in this reservoir. The replacement of radioactive source-based technology with the source-less LWD-NMR enabled efficient well placement and reservoir characterization for reservoir completion.