Calculate lime requirement for acidic soils or sulfur requirement for alkaline soils based on pH target and texture.
Calculate lime requirement for acidic soils or sulfur requirement for alkaline soils. Input current pH, target pH, field area, soil texture (sand/loam/clay), and incorporation depth. Get amendment amount per hectare and total, plus recommended material type. Optimal pH unlocks nutrient availability.
Your tomato plants had purple leaves and stunted growth — classic phosphorus deficiency. You applied 200 kg/ha of superphosphate, but the symptoms persisted. A soil test revealed pH 4.8 — at that pH, phosphorus is locked up as insoluble iron and aluminum phosphates. No amount of fertilizer would help until you raised pH. You applied 5 tons/ha of lime, waited 3 months, and the next crop was healthy. The $200 fertilizer was wasted; $150 lime would have solved the problem. Always check pH before fertilizing.
Soil pH affects nutrient availability, microbial activity, and crop growth. Most crops thrive at pH 6.0-7.5.
A: Each nutrient has an optimal pH range for availability. At pH 6.0-7.5: N, P, K, S, Ca, Mg all highly available. Below pH 5.5: P locks up with Fe/Al, Ca/Mg deficient, Mo unavailable, Al and Mn become toxic. Above pH 7.5: P locks up with Ca, Fe/Mn/Zn/B become insoluble (micronutrient deficiency). The classic "phosphorus deficiency" at low pH is not lack of P — it is P being chemically unavailable. Liming to pH 6.5 can release more P than a fertilizer application.
A: Ground limestone (calcium carbonate): 3-6 months for full reaction, some effect in 4-6 weeks. Hydrated lime (calcium hydroxide): 1-4 weeks (faster but more caustic, harder to handle). Pelleted lime: 2-3 months (easier to apply but more expensive). Factors affecting speed: particle size (finer = faster), soil moisture (moist = faster), incorporation (mixed in = faster than surface applied), soil temperature (warm = faster). Apply lime 2-3 months before planting for best effect. Do not apply lime and fertilizer at the same time — wait 2-3 weeks to avoid ammonia volatilization from nitrogen fertilizer.
A: Most vegetables and field crops: 6.0-7.0. Potatoes: 5.0-5.5 (lower pH reduces scab disease). Blueberries, azaleas, rhododendrons: 4.5-5.5 (acid-loving). Tea: 4.5-5.5. Most fruits: 6.0-6.5. Alfalfa: 6.5-7.5 (needs high pH for nitrogen fixation). Soybeans: 6.0-7.0. Corn: 5.8-7.0. Wheat: 6.0-7.0. If growing acid-loving crops, do NOT lime — test pH and apply sulfur if needed. Match your crops to your soil pH, or amend pH to match your crops.