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Agriculture Investment


    Plant mixtures differ to a large extent in nitrogen (N) composition. Nitrate-N: ammonium-N ratios vary according to raw material contents. The optimum nitrate: ammonium-ratio is close to 3:1 while 100% ammonium-N could impair plant growth and yield (Adriaanse 1990).


    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.

  • 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).

  • 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.

  • 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.


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