Problem 3 - Biology: The Dynamic Science

Question

Which of the following is/are not among the ideal soil conditions for growing crops? a. extremely large air spaces b. sandy or silty loam c. blend of sand and clay d. thick top soil e. less than \(5 \%\) humus

Step-by-Step Solution

Answer

The conditions that are not ideal for growing crops are a) extremely large air spaces, d) thick top soil and e) less than 5% humus.

Step 1: Identify ideal soil conditions

The ideal conditions for growing crops are a balance between air and water holding capacity, a soil texture that allows for good drainage, preferably a loam that is a mix of sand, silt and clay, a moderate top soil which is rich in organic matter and a humus content of around 5% to 10% which helps in nutrient supply.

Step 2: Analyze the given conditions

Look at each of the given conditions and evaluate whether it meets the requirements for ideal soil conditions as identified in step 1.

Step 3: Evaluate condition a

Extremely large air spaces in the soil means that the soil has poor water holding capacity which is not ideal for crop growth as it may lead to water stress in plants.

Step 4: Evaluate condition b

Sandy or silty loam is a good soil texture for crops as it has a good balance of water holding and draining capacity.

Step 5: Evaluate condition c

A blend of sand and clay can form a loam which is ideal for crop growth as it has a good balance between water holding and draining capacity.

Step 6: Evaluate condition d

Thick top soil is not necessarily ideal for crop growth. While top soil is important as it is rich in nutrients, if it is too thick, it can hinder the growth and development of plant roots.

Step 7: Evaluate condition e

Less than 5% humus content is not typically ideal. Humus is important for nutrient supply and a lower amount might not meet the nutritional requirements of growing crops.