Liming paddocks

In this activity, students measure the pH of soil collected from a paddock. This will be used to estimate the amount of agricultural lime needed to promote good grass growth.

By the end of this activity, students should be able to:

• apply a simple, but standard, sampling technique
• collect and appropriately process soil samples
• recall the meaning of pH and its relationship to acidity/basicity
• estimate soil type from a given set of guidelines
• use a given formula to calculate the amount of agricultural lime needed
• explain how agricultural lime helps to neutralise acid soils
• understand the meaning of the term ‘tonne/hectare’.

Download the Word file for:

• introduction/background notes
• what you need
• what to do
• student handout.

I recently used the Liming paddocks activity with my year 13 agriculture students (17-18 year olds). We went around the sports field and took samples of soil, dried it and then tested the pH. We were also able to use the soil description activity to find out the CEC of the soil. A brilliant activity. What made me proud is that these students told me that they were 'failures' at algebra, but after using the excellent formula, each student understood how algebra can be used in everyday life. We were also able to give the groundsman a recommendation for the school field.

I love the Science Learning Hub, you have made my ag/hort classes come to life.

Bronwyn Dyer, teacher