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ponder on in a changing world; ‘What if there
is no soil?’
The country would produce less food
against projected demand and this would
lead to higher food prices and the industry
would reach a crisis point which would trig-
ger a cycle of bigger effects such as health
and food security. He concluded his presen-
tation on sustainability of soil by saying that
we must get the system right by develop-
ing sustainable management practices and
agricultural products such as bio fertilisers.
Highlighting the implications of climate
change on agriculture, Prof Roland Schulze,
Centre for Water Resources Research, Uni-
versity of KwaZulu-Natal, indicated that our
current climate is anything but sustainable.
It impacts on the loss of fertiliser through
drainage which is caused by heavy rains
that takes away the soil nutrients.
Ultimately, this impacts on crop yields,
food security and of course the fertiliser in-
dustry. This was concluded with the need
to recognise that climate issues and change
are real. We need to implement adaptation
and improve on coping strategies; we also
need to realise that this is a multi-genera-
tional issue and admit the need to mitigate
and reduce emissions.
Last on the programme was Dr Herman van
Schalkwyk, group chief executive officer
of Suidwes Landbou, who spoke about the
competitiveness and the sustainability of
South African agriculture.
In order for the industry to reach long term
sustainability, the country has to be com-
petitive and this depends on a host of fac-
tors such as product quality, efficiency
and productivity as well as the capacity to
compete globally. However, the sustainable
advantage requires a continuous upgrading
of resources and as such we need strong
investment in resources while incorporating
old values.
In a nutshell, the Fertasa Congress encap-
sulated the representation of what current
affairs mean for the future of the agricultural
industry by taking into consideration the
direct and indirect linkages in this industry
and mapping out the supportable strategies
to be implemented in order to reach a com-
mon goal, which is sustainability.
5: Prof Isaiah Wakindiki
6: Prof Roland Schulze
7: Dr Herman van Schalkwyk
5
6
7
Onder omstandighede waar loging en vervlugtiging nie beperk is
nie en dit waarskynlik tot ‘n baie groter mate voorgekom het,
was die gemiddelde opbrengsvoordeel 13,6% vir KAN bo ureum
oor ses studies in drie lande (Bundy, 1992, Mangel en Hawkins,
1995, Avalis, 1998, ITGC, 2004, Gordon, 2008, Schwab en Mur-
dock, 2010).
Die opbrengsreaksie van ammoniumnitraat was oor drie studies
gemiddeld 8,2% hoër as met ureum plus NBPT, waar vervlugti-
ging ‘n rol sou speel en daar derhalwe ‘n positiewe reaksie op
urease-inhibeerders verwag is (Bundy, 1992, Gordon, 2008 en
Schwab en Murdock, 2010).
Die potensiële winsvoordele wat KAN bo ureum en ureum plus
NBPT volgens die aangehaalde internasionale navorsing inhou,
word vir bepaalde hipotetiese prysscenario’s ter illustrasie in
Tabel 1
tot
Tabel 3
uitgebeeld en in onderstaande gevolgtrekkings
aangespreek.
Vervoerkoste speel ‘n baie belangrike rol in gelewerde N-een-
heidsprysverskille tussen N-bronne en daarom behoort vergely-
kings vir elke lokaliteit afsonderlik gemaak te word. Die N-peil vir
‘n bepaalde opbrengs kan ook aansienlik van die gemiddelde syfers
in die tabelle verskil.
Veranderings in die mielieprys wat nie hier aangedui is nie, sal ook
die winsverskille tussen N-bronne beïnvloed. Aansienlike prysver-
skille is as vertrekpunt gebruik om winsverskille relatief daartoe
te illustreer en afleidings te maak.
Gevolgtrekkings
Wanneer KAN slegs ‘n 5,5% hoër opbrengs as ureum lewer
weens beperking van vervlugtiging en loging en die N-prys
van KAN is 55,7% hoër as dié van ureum, is dit meer wins-
gewend om KAN as ureum te gebruik – hetsy by R2 000/ton
of R3 000/ton mielies (Tabel 1). Indien KAN aansienlik meer
as 55,7% duurder as ureum is, mag dit moontlik by die hoë
N-peile vir hoër opbrengs by ‘n mielieprys van R2 000/ton
nie meer winsgewend as ureum wees nie.
Wanneer KAN 13,6% hoër opbrengs as ureum lewer, weens
geen beperking van vervlugtiging en loging nie (soos meer
algemeen voorkom) en die N-prys van KAN is 55,7% hoër as dié
van ureum, is dit meer winsgewend om KAN as ureum te ge-
bruik – hetsy by R2 000/ton of R3 000/ton mielies (Tabel 2).
Dieselfde afleiding behoort steeds by selfs groter prysverskille
as 55,7% gemaak te kan word.
Wanneer KAN 8,2% hoër opbrengs as ureum plus NBPT lewer
weens NBPT se beperking van vervlugtiging en toksisiteit en die
N-prys van KAN is 19,7% hoër as dié van ureum plus NBPT, is
dit meer winsgewend om KAN as ureum plus NBPT te gebruik
– hetsy by R2 000/ton of R3 000/ton mielies (Tabel 3). Dieselfde
afleiding behoort steeds by selfs groter prysverskille as 19,7%
gemaak te kan word.
Risiko’s verbonde aan die keuse van ‘n N-bron soos ernstige
vervlugtiging, loging en toksisiteit weens uitsonderlike kli-
maatsomstandighede soos droogte, hoë temperature en hoë
reënval, behoort bo en behalwe normale effektiwiteitsverskille
en winsverskille ook in die keuse van N-bronne in aanmerking
geneem te word.
Vir meer inligting kontak Sasol Chemikalieë. Let wel: Raadpleeg
‘n gekwalifiseerde landboukundige vir meer lokaliteit-spesifieke
toepassings.
Maak dit sin om meer vir KAN te betaal?