Agriculture Reference
In-Depth Information
TABLE 12.13
CA Practices Associated to Cropping and Management Patterns as Practiced
by Small-Scale Farmers in West Usambara Mountains, Tanzania
Cropping Patterns in Different Seasons
CA and Management Practices
Sept-Nov
Dec-Feb
June-Sept
March-June
Terrace: Animal manure, inorganic
fertilizers, crop residues, crop rotation
Beans, maize
NA
NA
Potatoes
Miraba : Animal manure, crop residues,
crop rotation, agroforestry
Beans, maize
NA
NA
Potatoes
Terrace: Animal manure, inorganic
fertilizers, crop residues, crop rotation
Beans, maize
NA
NA
Potatoes
Miraba : Animal manure, crop residues,
crop rotation, agroforestry
Beans, maize
NA
NA
Potatoes
Terrace: Animal manure, inorganic
fertilizers, crop residues, crop rotation
Beans, maize
NA
NA
Potatoes
Miraba: Animal manure, inorganic
fertilizers, crop residues, crop rotation,
agroforestry
Beans, maize
NA
NA
Potatoes
Raised beds: Animal manure, inorganic
fertilizers, crop residues, crop rotation
Cabbage
Tomatoes
Potatoes
NA
Source: Senior author's own field data.
Note: NA, not applicable.
September to November, followed by potatoes ( S. tuberosum ) and cabbage ( Brassica
oleracea ) in March to June for rainfed cropping on the sloping lands. For valley bot-
toms, the most common rotations were cabbage in September to November, toma-
toes ( Solanum lycopersicum ) in December to February, and potatoes from June to
September. The raised beds are constructed in valley bottoms to provide artificial
drainage (June-September). The drainage channels are then used for irrigation by
using buckets during the dry spell in September to December. During long rains, in
the months of March to June, the valley bottoms are not cultivated because of floods.
The drainage channels also act as a drainage system during flush floods. Beans
( P.  vulgaris ) were the only grown legume and known by the farmers to enhance
nitrogen availability in the soils. Most of the farmers (about 60%) were aware that
beans fix nitrogen through a symbiotic association with nitrogen-fixing bacteria.
They were also aware that residues from beans had higher nitrogen content, which
upon application on the farm as mulch can readily release nitrogen into the soil (Peel
1998; Yusuf et al. 2009). Beans were the sole legume crop commonly used by farm-
ers to improve soil fertility.
The comparison of soil chemical characteristics of fields with CA and non-CA
fields show that total nitrogen (TN) observed in terraces and miraba exhibits the
way CA can influence soil fertility when compared with non-CA fields (Table 12.14).
Relatively higher levels of organic carbon (OC) and TN in terraces and miraba were
 
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