Nitrogen Nutrition Know-How Quiz

Explore key aspects of nitrogen management in crop production, including cycle processes, fertilizer choices, deficiency symptoms, and best practices. This quiz helps reinforce practical knowledge of nitrogen nutrition in agriculture.

1. Nitrogen Cycle Processes

   Which process in the nitrogen cycle converts atmospheric nitrogen gas into a form usable by plants?

   1. Leaching
   2. Denitrification
   3. Nitrification
   4. Nitrogen fixation

   Explanation: Nitrogen fixation transforms atmospheric nitrogen into ammonium, which plants can use, mainly via certain bacteria. Nitrification converts ammonium to nitrate, leaching involves nutrient loss through water, and denitrification returns nitrogen to the atmosphere. Only fixation makes atmospheric nitrogen available to plants.

2. Fertilizer Application Timing

   When is the best time to apply nitrogen fertilizer to maximize crop uptake and minimize losses?

   1. Just before peak crop demand
   2. At seed harvest
   3. During prolonged drought
   4. Directly after heavy rainfall

   Explanation: Applying nitrogen just before the crop's maximum need aligns nutrient availability with plant uptake, reducing losses. After rain promotes leaching, while at harvest or during drought, crops use little nitrogen, so uptake efficiency is low.

3. Nitrogen Deficiency Symptoms

   What is a common visual sign of nitrogen deficiency in cereal crops such as wheat or maize?

   1. Purple coloring of stems
   2. Wilting of young leaves
   3. Brown spots on fruits
   4. Yellowing of older leaves

   Explanation: Nitrogen deficiency often leads to yellowing (chlorosis) of older leaves, as nitrogen is mobile and moves to new growth. Purple stems can indicate phosphorus issues, wilting young leaves suggests water stress, and fruit spots are unrelated to nitrogen.

4. Types of Nitrogen Fertilizers

   Which fertilizer listed is most immediately available for plant uptake after application?

   1. Ammonium nitrate
   2. Urea
   3. Anhydrous ammonia
   4. Rock phosphate

   Explanation: Ammonium nitrate provides both nitrate and ammonium forms, which plants can absorb quickly. Urea needs to be converted by soil microbes, anhydrous ammonia must react with moisture, and rock phosphate supplies phosphorus, not nitrogen.

5. Environmental Impact of Excess Nitrogen

   What environmental problem can result from excessive nitrogen fertilizer application in farming?

   1. Increased fruit sweetness
   2. Enhanced pest resistance
   3. Water body eutrophication
   4. Soil acidification only

   Explanation: Excess nitrogen can run off into waterways, causing overgrowth of algae (eutrophication) that harms aquatic life. Soil acidification can happen but is not the main environmental concern. Higher fruit sweetness and pest resistance are not typical results of nitrogen excess.