Explore essential concepts of nutrient management in agriculture, covering soil fertility, fertilizer choices, deficiency symptoms, and best practices for sustainable crop growth.
Which of the following best describes the primary role of nitrogen in plant development within agricultural soils?
Explanation: Nitrogen is crucial for the development of lush, green foliage as it is a major component of chlorophyll. While phosphorus strengthens root systems and potassium can increase resistance to some stresses, nitrogen does not directly enhance fruit sweetness or provide pest resistance.
A farmer notices stunted growth and purplish leaves in corn plants; which nutrient deficiency is most likely responsible?
Explanation: Phosphorus deficiency often causes stunted growth and purple discoloration due to its role in energy transfer. Magnesium deficiencies lead to yellowing between leaf veins, potassium causes leaf edge browning, and calcium deficiencies affect new leaf growth.
Why is regular soil testing recommended before fertilizer application in crop management?
Explanation: Soil testing measures nutrient content, allowing targeted fertilizer use and preventing over- or under-application. It does not directly influence pesticide effectiveness, rainfall absorption, or remove the necessity of crop rotation.
Which practice best increases organic matter and slow-release nutrients in soil?
Explanation: Composted manure enriches soil organic matter and provides nutrients slowly as it decomposes. Irrigation only adds water, pesticides target pests and do not supply nutrients, and leaving fields bare can deplete organic content.
What is a key benefit of crop rotation for soil nutrient management?
Explanation: Crop rotation alternates plant families, balancing nutrient demands and reducing depletion of specific soil nutrients. It does not eliminate weeds entirely, does not double water content, nor consistently affect the timing of harvest.