ABSTRACT
Norman Uphoff, Andrew S. Ball, Erick C.M. Fernandes, Hans Herren, Olivier Husson,
Cheryl Palm, Jules Pretty, Nteranya Sanginga and Janice E. Thies
CONTENTS
50.1 Processes Contributing to Sustainability .................................................................... 716
50.2 Nutrients in a Soil System Context.............................................................................. 717
50.3 Some Issues for Biologically-Driven Soil System Management.............................. 719
50.3.1 Optimizing the Use of Organic and Inorganic Inputs ................................ 719
50.3.2 Applicability to Commercial Agriculture...................................................... 720
50.3.3 Some Constraints to Be Addressed ................................................................ 721
50.3.3.1 Labor Intensity .................................................................................. 721
50.3.3.2 Biomass............................................................................................... 722
50.3.3.3 Training............................................................................................... 723
50.4 New Directions for Agriculture in the 21st Century ................................................ 724
50.4.1 Rationale for New Directions .......................................................................... 724
50.4.2 Paradigm Change .............................................................................................. 725
50.4.3 Knowledge-Driven Change ............................................................................. 726
References ................................................................................................................................... 726
Assessing sustainability is more difficult than evaluating productivity because it depends
on future evidence, which by definition cannot be known in the present. Certainly
sustainability is an aspiration for both the first and second paradigms for soil system
management. As seen in the previous chapter, there are reasons for questioning the
sustainability of Green Revolution technologies, with their heavy dependence on external
inputs. Nobody can know the future prices for petroleum, which will influence the cost of
energy for mechanized production and of inorganic fertilizers and many agrochemicals,
but recent data give no grounds for an optimistic view of agricultural input prices.
Biotechnology advances could possibly overcome the stagnation of cereal yields in most
major producing countries at some time in the future, but this is uncertain.
