Which soil conservation method involves growing different crops in alternate rows and sowing them at different times to protect the soil from being washed away by rain?

Introduction / Context:

This question relates to agricultural practices that help conserve soil and reduce erosion. Farmers use various methods to protect soil from being washed away by rain, especially on sloping land. The question specifically describes a method where different crops are grown in alternate rows and are sown at different times. We must match this description with the correct method name.

Given Data / Assumptions:

• The method uses more than one crop species in the same field at the same time.
• Crops are arranged in alternate rows or patterns rather than being mixed randomly.
• The sowing times of these crops are staggered.
• The purpose is to protect soil from rain wash and improve overall stability and productivity.

Concept / Approach:

Intercropping is an agricultural practice where two or more crops are grown together in the same field in a specific row pattern. This arrangement can reduce erosion, suppress weeds and improve nutrient use. When crops with different growth habits and sowing times are intercropped, they cover the soil more effectively throughout the season, reducing the impact of raindrops and surface runoff. Other methods like mulching, rock dam construction and terrace farming also conserve soil but do not match the specific pattern of alternate rows with different crops described in the question.

Step-by-Step Solution:

Verification / Alternative check:

Agricultural science descriptions of intercropping mention examples like growing maize and beans in alternating rows, or cotton with groundnut, where one crop may be sown earlier and another later. These combinations provide ground cover and reduce soil erosion. Mulching is instead the practice of covering soil with straw or plastic, terrace farming involves creating steps on slopes and rock dams are used in channels to slow water flow. None of these exactly match the alternating row pattern of different crops, which verifies intercropping as the answer.

Why Other Options Are Wrong:

Mulching involves spreading materials such as straw or leaves over the soil surface, not planting different crops in alternate rows. Rock dam construction refers to building small stone barriers across gullies or streams to slow water and prevent erosion, which is quite different from field cropping arrangements. Terrace farming uses level steps on hillsides to reduce slope length and erosion but may involve single or multiple crops; the defining feature is the terraces, not alternate crop rows. Strip cropping is related but usually involves long strips of crops and grass along contours, often with different species, yet the question emphasises alternate rows and timing, which aligns more closely with intercropping in basic textbooks.

Common Pitfalls:

Students sometimes confuse intercropping with mixed cropping or strip cropping because all involve more than one crop. Mixed cropping has crops sown randomly without definite row patterns, whereas the question specifies alternate rows. Strip cropping uses wide strips rather than row by row alternation. Recognising the emphasis on row pattern and timing points directly to intercropping.

Final Answer:

The described soil conservation method is Intercropping.