The Illinois Soil Nitrogen Test (ISNT) was developed for this purpose, and involves estimation of gaseous ammonia liberated by heating the soil with strong alkali in a Mason jar.

Try something like the PH soil test kit from Crocus, £13.99 if you want something extra user-friendly. Or, if you want to go more old school, there's another option: you could add vinegar to a ...

After more than a month of improvement, the water-soluble salt content of the test field dropped to 0.9 grams per kilogram of soil and the pH value plummeted to 7.6. Villager Jin Tangman, 63, was ...