📈 Correlating Soil Data with Crop Yields

Farm: 10 hectares of tomatoes
Data collected: 50 sample points across field

Correlation analysis:
- Soil pH vs Yield: R² = 0.82 (strong correlation)
- Nitrogen vs Yield: R² = 0.75 (good correlation)
- Organic Matter vs Yield: R² = 0.68 (moderate)

Key findings:
1. Best yields: pH 6.2-6.5, N 180-220 mg/kg
2. Worst yields: pH < 5.5 or > 7.5
3. Each 0.1 pH improvement increased yield by 2%

Action taken:
- Variable rate lime application in acidic zones
- Focused fertilizer in medium-yield zones
- Result: 35% average yield increase
        

📊 Creating Yield Maps:

// Pseudo-code for yield correlation
struct DataPoint {
    float n, p, k, ph, yield;
};

float calculateCorrelation(DataPoint points[], int count) {
    float sumXY = 0, sumX = 0, sumY = 0;
    float sumX2 = 0, sumY2 = 0;
    
    for (int i = 0; i < count; i++) {
        sumX += points[i].n;
        sumY += points[i].yield;
        sumXY += points[i].n * points[i].yield;
        sumX2 += points[i].n * points[i].n;
        sumY2 += points[i].yield * points[i].yield;
    }
    
    float numerator = count * sumXY - sumX * sumY;
    float denominator = sqrt((count*sumX2 - sumX*sumX) * 
                             (count*sumY2 - sumY*sumY));
    
    return numerator / denominator;  // R² value
}