368 Ecological Restoration and Design
Research on different approaches to soil system management is cumulating
across many countries, building upon decades of basic research conducted while
most investigations were still being carried out within the context of the first para-
digm. It is surprising to see how many of the seminal scientific studies published
on phytohormones, mycorrhizal associations and nitrogen cycling through proto-
zoa and nematodes, to take just three examples, were done in the 1950s, 1960s and
1970s, with little attention paid to them. However, this work has persisted and
matured over the past 50 years, strengthened now by new analytical techniques,
many at the molecular level, giving clearer outlines and more specificity to the
actors and processes in the soil food web that have been amorphous and inexact.
Their consequences for plant/crop performance and for agroecosystem function-
ing are becoming better known.
4.1 Rationale for new directions
The factors making the second paradigm more salient and attractive are numerous,
going beyond the accumulation of scientific knowledge that offers explanations for
the beneficial effects observed and measured. These include the following:
- Changing factor proportions – Land per capita ratios will require raising land
productivity through more intensive, i.e. less extensive, production strategies
as labour supply relative to land will continue to increase. Whether labour in
the agricultural sector becomes more productive will depend on the techno-
logical and institutional configurations that this century evolves. The scientific
basis for enhanced land and labour productivity through intensive manage-
ment of plants, soil, water and nutrients is available and growing. Especially
more productive utilization of freshwater resources will become imperative in
many countries and regions, making the enhancement of root growth and soil
biotic communities more essential. - Calculations of real cost are changing as environmental ‘externalities’ get fig-
ured into societal if not always individual assessments (Pretty et al, 2000;
Pretty, 2005; Tegtmeier and Duffy, 2005). Groundwater and soil contamina-
tion from N fertilizers and agrochemicals is increasingly subject to regulation
while the economic costs of their use become relatively greater. Economic and
environmental considerations are favouring movement toward management
strategies relying more upon intrinsic biological and ecological processes. - The disgrace of poverty and hunger that still afflict too many people on our
planet suggests that new approaches are called for in the agricultural sector,
where, ironically, most of the world’s hunger is still concentrated. External
input-dependent technologies continue to bypass the poor. Biological tech-
nologies can be adapted to the conditions of resource-limited households and
can be made to benefit producers and consumers.