An analysis of the financial implications of different tillage systems within different crop rotations in the Swartland area of the Western Cape, South Africa

[摘要] ENGLISH ABSTRACT: The pressure on the world's natural resources is increased by an expanding globalpopulation. The majority of the growth is expected to take place in Africa and Asia. Thiscreates the need for sustainable agricultural practices. To sustain food security, the limitednatural resources must be utilised efficiently to optimise agricultural productivity.Conservation agriculture (CA) is one of the most holistic sustainable agricultural practicesyet. It reduces environmental degradation, and concurrently it could enhance farmprofitability. The practice of CA is able to improve food security while sustaining theenvironment for the benefit of future generations of both consumers and producers. A largeproportion of the commercial grain producers in the Western Cape have adopted CA tovarying degrees. A purer form of CA practice is continually pursued to realise its full benefits.Adoption has taken place in the absence of any policy support framework directed to CA,and thus, has been market driven. The reasons for and rates of CA adoption in other regionsof the world differed, but was mostly successful, which highlights the driving forces behindadoption of CA in the Middle Swartland.The physical/biological benefits of CA are well known. The financial implications of thevarious systems within CA, at farm-level are still unknown. This study implements trial datafrom Langgewens experimental farm to evaluate the financial implications of various farmingsystems over an extended period.Farm systems are complex, consisting of numerous interrelated components. A whole-farmbudget model is developed within a systems approach to compare various farming systemsdesigned within CA principles. A trustworthy whole-farm model providing an accuraterepresentation of a real life farm requires insight across many scientific disciplines. Multidisciplinarygroup discussions are used to bridge the gap between scientific knowledge. Toserve as a basis for comparison, the whole-farm model was based on a typical farm withinthe Middle Swartland relative homogeneous farming area. Trial data on crop rotations andtillage systems from Langgewens experimental farm served as starting point for theresearch. The data was fitted for use in financial analysis and as input to the typical farmmodel. A key role of the inter-disciplinary expert group was to ensure that data and the modeldesign accurately reflect the underlying physical/biological processes of CA.The financial evaluation of the various farming systems showed that conventionalagricultural practices of monoculture and deep tillage are financially unsustainable. Farmingsystems under conventional tillage returned negative net present values (NPV) and aninternal rate of return on capital investment (IRR) lower than the real interest rate. Thisimplies that investment in conventional tillage will ultimately lead to financial losses. The financial benefits of CA are directly related to improved soil health, lower weed and peststress and improved yields. The CA farming systems were less susceptible to variations inexternal factors, highlighting the resilience of the system that incorporates crop rotation andno-till. The farming systems operated under conventional practices are expected to beunsustainable over a long-term period of 20 years.

[发布机构] Stellenbosch University