3. Soil physical properties
3.1. Bulk density
Tillage operations loosen, granulate, crush or even compact soil
particles and soil factors that influence plant growth, such as bulk
density, pore size distribution and the composition of the soil
atmosphere may be affected. High bulk density decreases the root
length and increases average root diameter of cassava.Lindstrom
and Onstad (1984) reported that ploughing reduced soil bulk
density while zero tillage has been shown to increase soil moisture
retention and infiltration and lower soil temperature. In a related
development, concentrations of organic carbon, total N, extractable P, exchangeable Ca, Mg and K have been shown in surface soil
of zero till than tilled plots (Dick, 1983).
Bulk densities (BD) within the different layers of soil is a
function of tillage system, the soil type and fertilizer management
adopted.Arvidsson (1998)on effects of cultivation in reduced
tillage on soil physical properties observed high bulk densities
within the layer 0–10 cm in compacted soils under chisel and
mouldboard plough (Table 1). He observed no difference in bulk
densities between the two treatments within the 10–25 cm layer
of soil due to soil compaction. Similar results were reported by
Christian and Bacon (1990), Arvidsson and Feiza (1995)andCarter
(1996).
Alvarez and Steinbach (2009)reviewed the effects of tillage on
some soil properties and discovered significantly high bulk density
under no-till than in plough tillage, but reported no difference
between plough and reduced tillage. This agrees with the findings
ofGantzer and Blake (1978)who reported significantly high bulk
density with no-tillage treatments compared with conventional
3. Soil physical properties
3.1. Bulk density
Tillage operations loosen, granulate, crush or even compact soil
particles and soil factors that influence plant growth, such as bulk
density, pore size distribution and the composition of the soil
atmosphere may be affected. High bulk density decreases the root
length and increases average root diameter of cassava.Lindstrom
and Onstad (1984) reported that ploughing reduced soil bulk
density while zero tillage has been shown to increase soil moisture
retention and infiltration and lower soil temperature. In a related
development, concentrations of organic carbon, total N, extractable P, exchangeable Ca, Mg and K have been shown in surface soil
of zero till than tilled plots (Dick, 1983).
Bulk densities (BD) within the different layers of soil is a
function of tillage system, the soil type and fertilizer management
adopted.Arvidsson (1998)on effects of cultivation in reduced
tillage on soil physical properties observed high bulk densities
within the layer 0–10 cm in compacted soils under chisel and
mouldboard plough (Table 1). He observed no difference in bulk
densities between the two treatments within the 10–25 cm layer
of soil due to soil compaction. Similar results were reported by
Christian and Bacon (1990), Arvidsson and Feiza (1995)andCarter
(1996).
Alvarez and Steinbach (2009)reviewed the effects of tillage on
some soil properties and discovered significantly high bulk density
under no-till than in plough tillage, but reported no difference
between plough and reduced tillage. This agrees with the findings
ofGantzer and Blake (1978)who reported significantly high bulk
density with no-tillage treatments compared with conventional
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