Rapitest Soil Test Kit, N-P-K-pH, 40 tests

10 ea for nitrogen, phosphorus, potash, pH  

Plants need the correct pH (acidity/alkalinity) level that controls how well plants utilize the nutrients available in your soil. Different plants have different pH preferences. This kit lets you quickly test your soil to determine its exact condition so that you can fertilize and/or adjust pH for best-growing results.

Includes 40 tests: 10 for pH, 10 for nitrogen (N), 10 for phosphorus (P), and 10 for potash (K) – with instructions, fertilization guidelines, and pH preference list for over 450 plants. Patented color comparator system.