A Smarter Fertiliser

Fertco is the distributor for Smartfert controlled-release nitrogen fertiliser. The product consists of a urea prill in an organic based polymer coating that controls the nitrogen release through the nano pores to match crop and pasture demand. The controlled release ensures less opportunity for N losses through volatilisation and leaching, increasing the efficiency of the fertiliser. That means less Smartfert is used than urea, for the same crop and pasture effects.

Fertco was formed by a group of farmers in 2000 and in the 16 years since, has brought to market many ground-breaking and efficient nutrient products, many of which are more sustainable than the alternatives. Among these products are dicalcic phosphate, granulated lime, prilled sulphur and now controlled-release urea nitrogen. Fertco has plants in Mt Maunganui and Morrinsville and sales consultants over the upper North Island.

Smartfert N controlled-release fertiliser is imported by environmental products company Eko360 and has been tested by independent soil scientist Dr. Doug Edmeades. Over three years under Dr. Edmeades’ guidance, AgResearch did both laboratory and glasshouse tests to validate the mode of nutrient release. That was followed by field trials on pasture with results proving significant increases in production could be achieved for each kilogram of nitrogen applied using Smartfert N when compared to standard urea.

The polymer coating allows Smartfert N to be applied in any weather and it can be mixed with other dry fertilisers as part of an overall fertiliser programme. One application of Smartfert N provides nitrogen for continuous plant growth over 3-4 months and on dairy and drystock pasture, nitrogen applications can be reduced to 2-3 times per year.

Smartfert’s nitrogen response happens over 90 days and the release curve is similar to the nitrogen demand curve of crops such as maize and other fodder crops. Moisture goes in through the polymer coating, dissolving the nitrogen in urea and then goes out again through the pores in the membrane, by osmosis. It is a true controlled release compared with other coated prills that require crushing or breaking open to release nutrients. The polymer coating goes transparent and retains shape during nitrogen release, after which it breaks down to soil particles.

In laboratory tests when fertiliser was flushed with water, Smartfert N released 5% of its nitrogen over 20 hours versus urea which released 100% of its nitrogen in five hours (the length of time it took to dissolve).

Smartfert can be applied with any other dry fertilisers because its protective polymer surface is non-reactive. It requires moisture to work and release the nitrogen within. The controlled release pattern also means that pasture responses to Smartfert will be slower initially than urea, but last a lot longer, months instead of weeks. Smartfert will begin releasing nitrogen once it is in contact with moist soil, without incorporation. However, if it is incorporated, the soil around the Smartfert prill is less likely to dry out and so the nitrogen release will be more consistent. Physical damage to the coating should be avoided during handling, which means in practice no auguring. The coating does not absorb moisture from the air, so the dry storage time for the product is long.

For use with cropping, Smartfert can be applied at the time of planting. The lag time of germination and establishment fits well with the release curve of the Smartfert prills. Heavy rain or flooding does not flush out the nitrogen, as the release is controlled by nano pore size.

The product retails at approximtely $1200 per ton. Smartfert comes in 25kg bags and 1T bulk bags. It is also sold as a mix with sulphate of ammonia (product name 44 Magnum) to give readily available nitrogen followed by controlled release nitrogen. Fertco also sells other blends of Smartfert with phosphates.