Of nitrogen

Nitrogen is the single most important nutrient in modern agriculture. Yields are typically doubled when nitrogen is applied at the optimum rate. Nitrogen also helps increase the amount of protein the plant can produce, thus lifting the nutritional value of the crop.

Nitrogen is often called “the key to yield”.  Deciding on optimal fertilizer rates and times for nitrogen applications is a major challenge if intensive agriculture is to be both profitable and lenient to the environment.

Yara has devoted a large part of its R&D programme to understanding which are the right nitrogen fertilizer products for the right crops and climatic conditions and then developing tools to help farmers apply them.

Nitrogen can be lost from the soil to water by leaching and to the air by de-nitrification or volatilization. Many countries have set limits on the nitrate-nitrogen concentration in drinking water, so leaching losses must be minimised. De-nitrification in wet soils leads to losses of nitrous oxide, a greenhouse gas, to the air. Most nitrous oxide lost from soil to air is of natural origin but a small proportion can be attributed to fertilizer application. Ammonia can be lost to the air following application of urea and can contribute to acidification. These losses of nitrogen from soil to water or to air can be minimised by careful matching of the application of fertilizer nitrogen to specific crop requirements, taking into account other sources of nitrogen to the crop.

Yara has introduced advisory systems and new technologies to help ensure accurate matching of nitrogen application to crop need.

The green colour of leaves is due to the pigment, chlorophyll, and there is a close relationship between the greenness of a leaf and a plant’s nitrogen status.

Yara has used the measurement of colour in the development of tools that a farmer can use. Translating the colour index into plant nitrogen status is a complex business, requiring the calibration for each crop, variety and growth stage.

Nitrogen requirement can fluctuate greatly between fields and even vary widely within the same field. Meeting this situation is called Precision Farming. Made possible by the Yara Precise tools.

The N-tester is a handheld tool that allows quick and reliable measurements of a plant’s nitrogen level. Readings are taken from the growing crop allowing the farmer to vary his nitrogen applications according to the actual situation in the field.

The N-Sensor is a tool that is mounted on the tractor cab. It measures the canopy reflectance using remote sensing technology, and analyses nitrogen levels as you drive automatically adjusting the fertilizer application rate "in real time". The latest ALS N-Sensor has a built-in light source, so can even be used at night.