Compare a podzol soil with a brown earth soil under the following headings: (i) Drainage - Leaving Cert Agricultural Science - Question 2 - 2016

Podzol soil is often leached and has poor fertility, as the acidic conditions lead to nutrient depletion. Brown earth soil, however, is generally more fertile due to a higher organic matter content and a neutral to slightly alkaline pH, encouraging a rich variety of plant life.

Podzol soils usually have an acidic pH, ranging from slightly acidic to strongly acidic, making it less suitable for many crops. In contrast, brown earth soils have a more neutral pH, which is ideal for a wider range of agricultural activities.

1. Wetting and Drying: The expansion and contraction of soil due to moisture changes create aggregates which improve structure.

2. Freezing and Thawing: This process breaks up soil aggregates, affecting soil texture and aeration.

3. Root Activity: Roots from plants and trees aid in breaking up soil and contributing organic matter.

4. Soil Organisms: Earthworms and other soil organisms improve soil structure by breaking down organic material and creating channels in the soil.

The experiment involved drying a soil sample to remove moisture, then crushing the aggregates into smaller pieces. The sample was then passed through a series of sieves, with the largest mesh on top, to categorize the particles by size. The weight of the soil retained on each sieve was recorded to determine the texture of the soil.

This soil is best suited for tillage crops, as its texture allows for good aeration and drainage, essential for crops such as vegetables and grains.

1. Good Drainage: The sand content provides excellent drainage, reducing waterlogging issues.

2. Aeration: The soil structure allows for better root development and nutrient uptake.

3. Nutrient Retention: The balance of sand and silt ensures nutrients are retained and available for crops.