SCSC 301 Final Howe Questions With Complete Solutions

When organic-N is converted into ammonia or ammonium, the process is called? correct answer: Ammonification During nitrification, ______ is converted to ______ correct answer: Ammonium; Nitrate Which soil minerals are likely to trap, or fix, NH4+ and K+ in their interlayer making them relatively unavailable to plants? correct answer: Vermiculite and mica Which answer best describes denitrification? correct answer: Conversion of nitrate to gaseous N (e.g., NO, N2O, N2) under low/no oxygen by microbes Today, most of the plant available S comes from which source, if the soil is low in sulfur-containing minerals correct answer: Mineralization of S in organic mater The plant-available form of sulfur is: correct answer: SO4^-2 Biological nitrogen fixation is second to photosynthesis as one of the most important biological reactions for life. Which answer best describes symbiotic N fixation? correct answer: Conversion of gaseous atmospheric N2 to biological forms of nitrogen by microbes that are in a symbiotic relationship with a specific plant host. Phosphorus is most available to plants when the pH is: correct answer: between 6 and 7 Which of the following best describes the phosphorus fertility problem? correct answer: P is insoluble and unavailable to plants, and additions of new P become insoluble very quickly. Which of the following is most likely to apply to a plant in a native ecosystem where P fertilizer is not applied. correct answer: Native plants are likely to rely on mineralization of organic P or associate with mycorrhizae that can help them acquire P In natural systems (i.e., non-fertilized), the major source of K for plants is from _______ correct answer: Solution and exchangeable K that comes from weathering of primary minerals, as well as K from plant and animal residues Potassium losses from acid, sandy soils occur mainly due to: correct answer: soil leaching Many micronutrients (e.g., Fe, Mn, Cu, Zn) occur in an ion form with a _________charge correct answer: +2 The micronutrients most likely to be deficient to plants grown on calcareous soils are ________ correct answer: Iron and manganese Available calcium and magnesium in acid soils is usually low, but these elements are not usually limiting when these soils are in agronomic production because_______ correct answer: Acidic soils are typically limed prior to production. Agricultural lime typically contains both calcite and dolomite, which provide Ca and Mg as well as increase pH Urea is a common fertilizer that provides ________ correct answer: N Which of the following would be used to create an integrated strategy with specific practices for how nutrients will be used in plant and animal production correct answer: Nutrient Management Plans Which is a major goal of N fertilization? correct answer: