609
(i) present the key findings from research projects undertaken in the CABMACC
Program and other research projects conducted by LUANAR and its
partners,
(ii) provide an opportunity for researchers from universities and other institutions
in SSA region including those under the NORHED program to share their
research findings in several areas including conservation agriculture, sustainable soil management, soil and crop health, integrated crop/livestock/aquaculture/agroforestry systems on smallholder farms, market access, climate change
and food and nutrition security,
(iii) explore possibilities for increased collaboration between African institutions
(south-south collaboration), and
(iv) produce quality scientific publications in a book form by a reputed publisher.
3 Soil Resources and Degradation
Soil degradation, decline in quality and functionality of the soil due to natural
and anthropogenic factors, is a major global issue of the twenty-first century.
Soil degradation, a biophysical process but driven by the human dimensions
(Lal 2008), is also likely to increase with the increase in climate change. Indeed,
soil degradation is affected by the climate change. By exacerbating emission of
greenhouse gases (GHGs), soil degradation creates a positive feedback to climate change. Thus, restoration and sustainable management of soil to minimize
risks of soil degradation is important to adaptation and mitigation of climate
change and advancing sustainable development goals of the United Nations (Lal
et al. 2018b). It is estimated that a third of Earth’s soil is severely degraded due
to agricultural and other anthropogenic activities, and the fertile topsoil is being
lost at a high rate (Watts 2018). There are several processes of soil degradation
(Fig. 1). The physical process involves loss of soil structure, resulting in crusting, compaction, hard setting, runoff, and erosion by water and wind. Accelerated
soil erosion, affecting 1.1 Bha by water erosion and 0.55 Bha by wind erosion
(Oldeman 1994), is the most widespread problem. Human activities related to
land-use change are the primary cause of accelerated soil erosion, and the
annual loss of topsoil may be much higher than 35.9 Gt/yr. (Borrelli et al. 2017).
Some have argued that degradation is so serious that only 60 years of farming
will be left if the soil degradation continues at the same rate (Arsenault 2014).
Global soil erosion has a strong impact on global carbon cycling (Lal 2003),
with the attendant impact on changes in the hydrological and elemental cycling.
The process of soil chemical degradation encompasses acidification, salinization, nutrient depletion, elemental imbalance, and reduction in cation/anion
exchange capacity of the soil. Salinization, increase in concentration of soluble
salts in the root zone, affects a large tract of land in arid and semi-arid regions.
Secondary salinization, already affecting 20% of irrigated lands and likely to
increase as climate change increases, is a major global issue. Severe adverse
Knowledge Gaps and Research Priorities
(i) present the key findings from research projects undertaken in the CABMACC
Program and other research projects conducted by LUANAR and its
partners,
(ii) provide an opportunity for researchers from universities and other institutions
in SSA region including those under the NORHED program to share their
research findings in several areas including conservation agriculture, sustainable soil management, soil and crop health, integrated crop/livestock/aquaculture/agroforestry systems on smallholder farms, market access, climate change
and food and nutrition security,
(iii) explore possibilities for increased collaboration between African institutions
(south-south collaboration), and
(iv) produce quality scientific publications in a book form by a reputed publisher.
3 Soil Resources and Degradation
Soil degradation, decline in quality and functionality of the soil due to natural
and anthropogenic factors, is a major global issue of the twenty-first century.
Soil degradation, a biophysical process but driven by the human dimensions
(Lal 2008), is also likely to increase with the increase in climate change. Indeed,
soil degradation is affected by the climate change. By exacerbating emission of
greenhouse gases (GHGs), soil degradation creates a positive feedback to climate change. Thus, restoration and sustainable management of soil to minimize
risks of soil degradation is important to adaptation and mitigation of climate
change and advancing sustainable development goals of the United Nations (Lal
et al. 2018b). It is estimated that a third of Earth’s soil is severely degraded due
to agricultural and other anthropogenic activities, and the fertile topsoil is being
lost at a high rate (Watts 2018). There are several processes of soil degradation
(Fig. 1). The physical process involves loss of soil structure, resulting in crusting, compaction, hard setting, runoff, and erosion by water and wind. Accelerated
soil erosion, affecting 1.1 Bha by water erosion and 0.55 Bha by wind erosion
(Oldeman 1994), is the most widespread problem. Human activities related to
land-use change are the primary cause of accelerated soil erosion, and the
annual loss of topsoil may be much higher than 35.9 Gt/yr. (Borrelli et al. 2017).
Some have argued that degradation is so serious that only 60 years of farming
will be left if the soil degradation continues at the same rate (Arsenault 2014).
Global soil erosion has a strong impact on global carbon cycling (Lal 2003),
with the attendant impact on changes in the hydrological and elemental cycling.
The process of soil chemical degradation encompasses acidification, salinization, nutrient depletion, elemental imbalance, and reduction in cation/anion
exchange capacity of the soil. Salinization, increase in concentration of soluble
salts in the root zone, affects a large tract of land in arid and semi-arid regions.
Secondary salinization, already affecting 20% of irrigated lands and likely to
increase as climate change increases, is a major global issue. Severe adverse
Knowledge Gaps and Research Priorities