Agriculture Reference
In-Depth Information
TABLE 1.1
Factors Affecting Low Crop Yields and Agronomic Productivity of
Small Landholders in Developing Countries
Factor
Region
Reference
1. Climate change (drought) and land
degradation
Northern Ghana
Laube et al. (2012)
2. Soil fertility depletion and nutrient
mining
Sub-Saharan Africa
Bekunda et al. (2010)
3. Lack of access and capacity to
efficiently apply fertilizers
Sub-Saharan Africa
Bekunda et al. (2010)
4. Spatial variability in soil fertility
Western Kenya
Tittonell et al. (2005)
5. Imbalance of plant nutrients in soil
Southwest Mexico
Flores-Sanchez et al. (2011)
6. Drought risks
Honduras
Nieto et al. (2010)
7. Poverty and low soil quality
Honduras
Ravnborg (2002)
8. Land degradation, genetic erosion,
and poverty
Columbian
Highlands
Ashby et al. (1999)
are in transition. They are being linked with market and high-value chain, and are
adapting to changing climate and market dynamics. Small landholders contribute
strongly to agricultural production and global food security, and deserve to receive
attention and support for improving production and environment quality. Small
farms must not be marginalized and should be the focus of developmental programs
(Hazell et al. 2006). Because most smallholders practice mixed farming, pastures
can also be improved with good management.
1.3 SEEDBED PREPARATION
Fire has been a widely used tool in land clearance and seedbed preparation. Slash-
and-burn agriculture has been practiced for millennia, and is still being practiced
by small landholders in the tropics and subtropics. Seedbed preparation even on
peatlands in Indonesia involves controlled burning. Destruction of 10 Mha of forests
and nonforest lands in 1997 in Indonesia, resulting in more 2 Pg C emission into the
atmosphere, was caused by the fire started on agricultural land and forestry planta-
tions (Saharjo and Munoz 2005).
Most smallholder farmers use some tillage for seedbed preparation and believe
that tillage increases crop yield. This belief is based on the short-term benefits of
tillage through breaking the surface crust and loosening the soil, improving water
infiltration, controlling weeds, and accelerating decomposition of SOM, which min-
eralizes plant nutrients and makes these available to crop. Whereas the merits of
no-till (NT) farming have been documented by research experimentation for a range
of soils and agroecosystems (Table 1.2), there are numerous constraints to its adop-
tion by resource-poor farmers (Table 1.3). Lack of appropriate seeding and other