pH 5.8 - 6.5

Improved microbial activity can lead to better soil structure which, in turn, results in improved soil aeration and water-storage. These lead to increased plant growth, especially in summer and autumn.

Maintaining soil pH at 5.8 - 6.2 is an essential part of pasture management. Most soils in New Zealand are naturally acidic and will produce low yields without lime or lime-based fertilisers. If the soil pH is too high or too low, certain nutrients needed for plant growth are less available for uptake. This leads to plant nutrient deficiencies and poor yields.

Soil with ideal pH also encourages earthworm activity, which means:

  • Better soil aeration.
  • Improved root growth.

Soil has greater resistance to compaction and bounces back to optimum production quicker after adverse field conditions.

  • You can apply lime on its own or you can use Dicalcic (and get P as well).
  • Continuously applying Dicalcic as part of your fertiliser plan can gradually increase soil pH (especially on hill country where you generally need more fertiliser per stock unit).

Yes, it’s essential if you want to maximise production from your land.

  • Lime has a great effect on soil conditioning it to the ideal pH for plant growth and production – without its conditioning properties you can be wasting a lot of your fertiliser inputs.
  • It’s suggested about 15kg of lime per stock unit is required per annum to maintain soil pH. On average it takes 1 tonne to raise soil pH 0.1 of a unit, which is 1 tonne per hectare.

TerraCare Dicalcic Phosphates are rich in calcium – which contributes to a higher soil pH

  • The higher the levels of soil microbes, the greater the rate of breakdown of fresh organic matter, which means nutrients are recycled to sustain plant growth much faster.
  • Microbes improve soil structure by helping to bind soil particles together which improves aeration and the soil’s capacity to store water.
  • Clover needs specific microbes – Rhizobia - to help fix nitrogen. The Rhizobia species needed by clovers thrive best at soil pH levels between 6.0 and 6.5, so keeping soil pH in the ideal range will increase the amount of nitrogen fixed – reducing the need for urea. Clover can supply up to 220kg N/ha/yr).

Earthworm activity improves the soil structure by providing:

  • Better aeration.
  • Better environment for root growth (easier root penetration).
  • Greater resistance to compaction and quicker return to production after adverse field conditions (pugging, flooding, drought etc.)
  • Influence on increasing organic matter decomposition and the ensuing nutrient availability

Earthworm counts respond well to increases in both calcium and soil pH levels.

  • Microbial activity in the soil declines when the pH level decreases below 6.0 pH.
  • Through the process of growing plants, soil will naturally become more acid. The use of phosphate and nitrogen products such as urea and DAP stimulate plant growth which will cause the soil pH to decrease (in the absence of regular lime applications). This has the effect of reducing soil microbial activity.
  • Dicalcic differs from superphosphate as it has more calcium per unit of P applied; this means that it will absorb acid from the soil to become available, helping to counter the acidifying effect of plant growth. Some dicalcic fertiliser products also contain calcium carbonate which also reduces soil acidity.