Conservation agriculture
Inputs/Production
Conservation agriculture awareness
dialogues with Dr Rolf Derpsch
DR HENDRIK SMITH, CONSERVATION AGRICULTURE FACILITATOR, GRAIN SA
For two days in August, Grain SA’s Conservation Agriculture (CA)
programme entertained a number of participants with two awareness
events with Dr Rolf Derpsch as presenter.
On the 14th the event was held in Pretoria for the Limpopo, Mpumalanga
and Gauteng provinces and on the 15th at NAMPO Park in Bothaville for
the Free State and North West Provinces.
These events were attended by 60 (Pretoria) and 100 people (Bothaville)
respectively and were characterised by lively discussions among
the participants, after presentations by Dr Derpsch and some of the
producers. These producers include: Willem van der Walt, Ralf Küsel,
Tony da Costa, André de Villiers, Hannes Otto, Pietman Botha (advisor),
Cobus van Coller and Wynn Dedwith.
Dr Derpsch has extensive experience on CA from almost all parts of the
world, but was instrumental in the development of CA in Paraguay and
Brazil from the early 1970s, which has led to its wide-scale adoption in
those countries.
On the 14th and 15th, he first shared some key and practical ideas from
his experiences in the successful introduction of CA with producers
across the world, which was then followed by a question and answer
session and discussions until the end of the day.
The information and lessons learned during these events are seen as
critical to improve practices of existing CA producers, but also to spark
the interest and knowledge of producers interested to start CA. In more
detail the dialogue with Dr Derpsch during the first event is elaborated
below.
Q: What do you have to monitor in CA? What are you looking for
in CA?
A: The more important question is “when” to look. Timelines (activity
schedule) is very important: Actions should take place exactly when they
need to take place; doing things at the right time is the key to success in
any agricultural system. It is important to monitor soil fertility and the
build-up of soil cover and soil organic matter.
Monitor weeds, for better control. Some diseases or pests may decrease,
others may increase, but at the end there will be a balance. The situation
changes in CA, since natural enemies of pests are not (always) killed.
The idea is to observe nature and identify different species, enhancing
biological control.
Q: What about the integration of animals in a CA system?
A: It is very positive, especially in cases where rotation happens.
However, in some cases, crop residues are removed in excess. When you
have excess residues, you may remove some.
Q: What about tines in a no-till planter (compared to discs), since
South African topsoil is difficult and has an “inherent motor”
to compact? Is the best not to use a tine during the transition
phase?
A: Frank Dykstra (in Brazil) is farming in very sandy soils and has been
practicing CA for 40 years without a need to rip the soils.
31
January 2014
Part I: Pretoria, 14 August 2013
Continued on page 32
No-till soybeans at the Parex farm in Paraguay with red clay soil.
