A soil scientist measures organic matter in 15 soil samples. Each sample weighs 500 grams before drying. After drying, each loses 22% of its mass. She randomly selects 10 samples for high-precision analysis requiring 40 grams each. How many grams of dried soil remain after allocation?

Mon, 04 May 2026 14:12:35 +0000

**How Organic Matter Analysis Reveals Hidden Soil Insights — And How Much Remains After Testing** In an era defined by heightened interest in sustainability, agriculture, and climate resilience, understanding soil health has never been more relevant. When a soil scientist measures organic matter across multiple samples—each weighing 500 grams before drying—this process uncovers vital data shaping farming practices, environmental policy, and carbon management strategies. By analyzing precise mass reductions from natural drying, researchers gain insight into a key indicator of soil fertility and carbon storage. This seemingly simple calculation holds growing attention, driven by rising awareness of how soil impacts food systems, water cycles, and climate change. The process begins with 15 soil samples, each starting at 500 grams. After controlled drying, each sample loses 22% of its original mass—a natural transformation influenced by moisture evaporation. This reliable outcome allows scientists to standardize testing across field conditions. From these 15 samples, a select 10 are chosen based on random sampling protocols to ensure representative analysis. These receive 40 grams each for high-precision testing, creating a clean demand for usable material. Understanding what remains after allocation helps researchers plan efficient use of limited soil resources, especially in expensive or rare sample batches. **How the Calculations Work**
Mixture integrity in soil science hinges on precise mass accounting. Each of the 10 analyzed samples begins at 500 grams and loses 22% mass through drying:
22% of 500 grams is 110 grams, so each sample retains 390 grams after drying.
Multiply this by 10 samples: 10 × 390 grams equals 3,900 grams of dried soil used.
Initial total dried soil from the 10 samples is 10 × 400 grams (the required allocation), totaling 4,000 grams.
Subtract allocated amount from initial total: 4,000 – 3,900 = 100 grams remain unallocated.