How do I read a soil texture diagram and determine the texture class for a soil sample with 50% sand, 20% clay, and 25% silt?

You're on a roll — Step 1: Understand how to read the soil texture diagram. The diagram is a ternary plot with three axes representing the percentages of sand, clay, and silt. • % Sand is read along the bottom axis, with lines running diagonally upwards to the left. • % Clay is read along the left axis, with lines running horizontally to the right. • % Silt is read along the right axis, with lines running diagonally downwards to the left. The sum of the percentages of sand, clay, and silt for any soil sample must equal 100\%. Step 2: Determine the texture class for each soil sample in 1.1.1. a) Sample A: 50\% sand, 20\% clay, 25\% silt First, check if the percentages sum to 100\%: 50\% + 20\% + 25\% = 95\%. This sum is not 100\%. Assuming there's a typo and the silt percentage should be 30\% to make it 100\%, or that the question implies the given values are approximate and we should use them as is. Given the context of soil science, it's highly likely the sum should be 100\%. Let's assume the question intends for the sum to be 100\% and there's a slight error in the silt value, or that the values are to be plotted as given and the closest region identified. Let's re-evaluate the sum: 50\% sand + 20\% clay + 25\% silt = 95\%. This is a common issue in these types of questions. If we strictly follow the given numbers, we plot 50\% sand, 20\% clay, and 25\% silt. • Find 50\% on the sand axis (bottom, reading right to left). Follow the line diagonally up-left. • Find 20\% on the clay axis (left, reading bottom to top). Follow the line horizontally right. • Find 25\% on the silt axis (right, reading top to bottom). Follow the line diagonally down-left. The intersection of these three lines falls within the region labeled sandy clay loam. b) Sample B: 40\% sand, 50\% clay, 10\% silt Check sum: 40\% + 50\% + 10\% = 100\%. This is a valid sample. • Find 40\% on the sand axis. Follow the line diagonally up-left. • Find 50\% on the clay axis. Follow the line horizontally right. • Find 10\% on the silt axis. Follow the line diagonally down-left. The intersection of these three lines falls within the region labeled clay. c) Sample C: 94\% sand, 3\% clay, 2\% silt Check sum: 94\% + 3\% + 2\% = 99\%. This is also not exactly 100\%. Similar to sample A, we will plot the given values. • Find 94\% on the sand axis (very close to 90\% and 100\%). Follow the line diagonally up-left. • Find 3\% on the clay axis (very close to the bottom). Follow the line horizontally right. • Find 2\% on the silt axis (very close to the bottom right). Follow the line diagonally down-left. The intersection of these three lines falls within the region labeled sand. 1.1.1 The texture classes are: a) Sample A: sandy clay loam b) Sample B: clay c) Sample C: sand Step 3: Indicate which sample (A, B, and C) applies to the given characteristics in 1.1.2. a) Suitable for pottery work in rural communities Pottery requires soil with high plasticity and ability to hold shape, which is characteristic of soils with a high clay content. Sample B is clay, which is highly suitable for pottery. b) Most suitable for cultivation The most suitable soil for cultivation is typically a loam, which has a balanced mix of sand, silt, and clay, providing good drainage, water retention, and nutrient availability. • Sample A (sandy clay loam) has a good balance and is generally fertile. • Sample B (clay) can be too heavy, poorly drained, and difficult to work. • Sample C (sand) drains too quickly and has poor nutrient retention. Therefore, Sample A (sandy clay loam) is the most suitable for cultivation among the given options. 1.1.2 The samples that apply are: a) Suitable for pottery work in rural communities: Sample B b) Most suitable for cultivation: Sample A Send me the next one 📸