Despite the aftermath of the global recession still being felt in my countries across the globe, South Africa has seen considerable growth in its developing sectors.

Dr Erik Adriaanse, Manager Technology and Special Projects, Sasol Nitro

Most crops will perform best when receiving 75 % nitrate–N and 25% ammonium-N while 100 % ammonium-N would be toxic (Adriaanse, 1990). LAN consists of 50% nitrate-N and 50% ammonium-N. Shortly after application of LAN, part of the ammonium-N will be converted to nitrate-N.

Dr Erik Adriaanse, Manager: Product Development and Technical Support

The quantity of measurable inorganic N that should be in the soil throughout the growing period for maximum yield does not differ between El Nino (dry) or La Nina (wet) or average rainfall seasons but the actual yield, profitability and risk will differ to a large extent between these conditions.

Nitrogen (N) is normally more efficiently utilised when applied 4 to 8 weeks after planting under high rainfall conditions compared to pre-plant applications (Grove et. al., 1980). In contrast, most N applied 2 weeks after planting showed higher yields than later applications at 5 and 9 weeks after planting under relatively dry conditions (Adriaanse and Human 1993).

Volatilisation of applied nitrogen is primarily in the form of ammonia (NH3), although losses in the form of atmospheric nitrogen (N2 en N2O) may also occur when soils are waterlogged.

Inorganic nitrogen (N) dissolved in groundwater could be lost for crop production through downward and sideway movements of groundwater, resulting in lower yields and profit margins above costs. Differences in leaching between N sources can effectively be utilised to reduce the risk of N leaching.