Question

Excess of nitrogenous fertilizers is harmful because they (a) increase the acidity of the soil (b) do not get distributed uniformly in the soil (c) get leached away from the soil easily and pollute the water bodies (d) produce extra heat which burns plants

Short answer

Answer: Excess nitrogenous fertilizers are harmful because they get leached away from the soil easily and pollute the water bodies.

Step-by-step solution

Study each option

Familiarize yourself with each option provided and analyze them individually. Option a) Increase the acidity of the soil Option b) Do not get distributed uniformly in the soil Option c) Get leached away from the soil easily and pollute the water bodies Option d) Produce extra heat which burns plants

Evaluate the options based on the effects of nitrogenous fertilizers

Analyze the options based on the knowledge about the harmful effects of excess nitrogenous fertilizers, and evaluate if each statement is true or false. Option a) Can be true, as heavy application of nitrogen fertilizers may result in soil acidification. Option b) May not be an ideal answer, as the uniform distribution of fertilizers depends on various factors such as application methods and soil properties, rather than being a direct effect of nitrogenous fertilizers themselves. Option c) True, as excess nitrogenous fertilizers tend to get leached away, polluting the water bodies and causing environmental issues like eutrophication. Option d) False, as excess nitrogenous fertilizers do not produce extra heat that can burn plants.

Choose the most appropriate answer

Based on our evaluation, we can conclude that Option c) is the most appropriate answer to the question, as it accurately describes the harmful effect of excess nitrogenous fertilizers on water bodies and the environment. Answer: c) Excess nitrogenous fertilizers are harmful because they get leached away from the soil easily and pollute the water bodies.

Key concepts

Soil Acidification

Soil acidification is a process where the pH level of the soil decreases over time, becoming more acidic. This can occur as a result of the overuse of nitrogenous fertilizers. Nitrogen from these fertilizers can be converted into nitric acid through biological processes, lowering the soil pH. This affects soil health by reducing the availability of essential nutrients to plants and can lead to decreased agricultural productivity.

Acidic soils can also disrupt the balance of microbial communities, which are essential for decomposing organic matter and recycling soil nutrients. Over time, plants grow less vigorously and soils become less fertile, which can compel farmers to apply even more fertilizers, perpetuating a harmful cycle. Understanding soil pH and proper fertilizer application is crucial to prevent such detrimental outcomes.

Fertilizer Leaching

Fertilizer leaching is when nutrients, like nitrogen from nitrogenous fertilizers, are washed through the soil profile and beyond the root zone of plants. This often happens with excess rainfall or irrigation. Instead of being used by crops, these nutrients find their way into groundwater or surface water systems.

Leached nitrogen compounds, primarily in the form of nitrates, contaminate drinking water supplies and can lead to health problems such as methemoglobinemia, or 'blue baby syndrome' in infants. They also represent a waste of agricultural inputs, leading to economic losses for farmers. Proper fertilizer management, like matching application rates to plant needs and using slow-release formulas, can help mitigate leaching.

Water Pollution

Water pollution from nitrogenous fertilizers is a significant environmental concern. When fertilizers are leached from soils, they carry with them high levels of nitrogen into waterways. This not only contaminates drinking water but also disrupts aquatic ecosystems.

Nitrogen in water bodies can stimulate the growth of certain bacteria and algae. Some algae blooms can produce toxins harmful to both aquatic life and humans. Additionally, these pollutants can affect the recreational use of water bodies and reduce the commercial value of water resources. Preventive measures include the use of buffer strips alongside waterways, controlled-release fertilizers, and precision farming techniques.

Eutrophication

Eutrophication is an ecological phenomenon where bodies of water receive excess nutrients, leading to overgrowth of algae and depletion of oxygen in the water. Nitrogenous fertilizers, when leached into water systems, act as a fertilizer for aquatic plants and algae, causing unnaturally rapid growth, known as algal blooms.

As algae die and decompose, significant amounts of oxygen in the water are consumed, creating 'dead zones' where aquatic life cannot survive due to lack of oxygen. Eutrophication not only damages ecosystems but also affects fisheries, tourism, and water quality. To combat eutrophication, it is vital to improve agricultural practices and manage wastewater and industrial discharges effectively.