A rich harvest in vegetable or allotment gardens requires regular fertilization, as plants need macronutrients such as nitrogen, phosphorus and potassium for their growth process. Potassium improves the quality of the crop and facilitates the absorption of water and other nutrients. To prevent nutrient deficiencies and weak harvests, organic fertilizers, which combat soil pollution, are the most effective. Potassium nitrate (KNO3) is a prominent organic fertilizer that contains both potassium and nitrate. For optimal results, approximately 100 grams of potassium nitrate should be spread evenly per square meter of garden. The product is available from DutchChems in its purest form.