A problem with intensive irrigation is
a. Overfertilization.
b. Aquifer depletion.
c. The long-term depletion of soil oxygen.
d. The clogging of waterways by vegetation debris.

Verified step by step guidance

1. Step 1: Begin by understanding the concept of intensive irrigation. Intensive irrigation refers to the practice of applying large amounts of water to agricultural fields to support crop growth, often in areas with limited natural rainfall.
2. Step 2: Analyze each option provided in the problem to determine its relevance to intensive irrigation. For example, consider whether overfertilization (option a) is directly caused by irrigation or if it is more related to the excessive use of fertilizers.
3. Step 3: Evaluate aquifer depletion (option b). Aquifer depletion occurs when groundwater sources are overused, which can be a direct consequence of intensive irrigation practices that rely heavily on groundwater extraction.
4. Step 4: Examine the long-term depletion of soil oxygen (option c). Consider whether intensive irrigation could lead to waterlogging, which might reduce oxygen availability in the soil, but assess if this is a primary issue compared to aquifer depletion.
5. Step 5: Assess the clogging of waterways by vegetation debris (option d). Determine if this is a direct result of irrigation or if it is more related to other agricultural practices, such as runoff or improper waste management.

Key Concepts

Intensive Irrigation

Intensive irrigation refers to the practice of applying large amounts of water to crops to maximize yield. While it can enhance agricultural productivity, it often leads to negative environmental impacts, such as soil degradation and water resource depletion. Understanding the balance between water use and crop needs is crucial for sustainable agriculture.

Aquifer Depletion

Aquifer depletion occurs when groundwater is extracted faster than it can be replenished, often due to excessive irrigation. This can lead to a significant drop in water tables, affecting not only agricultural practices but also drinking water supplies and local ecosystems. Awareness of aquifer health is essential for sustainable water management.

Overfertilization

Overfertilization happens when excessive fertilizers are applied to crops, leading to nutrient runoff into waterways. This can cause environmental issues such as algal blooms, which deplete oxygen in water bodies and harm aquatic life. Understanding the relationship between fertilizer use and environmental health is vital for sustainable farming practices.