Abstract:
In the southern Uluguru Mountains, conventional farming practice that involves slash and burn
followed by conventional cultivation on steep slopes has resulted in declining soil fertility due to
soil erosion and limited fertilizer use. Progressive declines in crop yields under conventional
farming practices force farmers to abandon their fields to other pieces of land. This has led to an
increasing encroachment into catchment forests and other marginal lands. A study was carried
out for four cropping seasons from 2013 to 2016 whereby Conservation Agriculture (CA)
technologies that involved Zero and Minimum tillage with legume (lablab and cowpea)
intercropping as well as crop residue retention were evaluated for their ability to improve and
sustain production in the southern Uluguru Mountains. Results indicated a gradual improvement
in soil fertility and yields as a result of the use of CA technologies compared to Conventional
practices (T1M1) that showed a gradual decrease in yields. The best CA treatment (T3M1) (Zero
till with sole maize) had a 58 % increase in maize yield compared to the Conventional practice.
Determination of the benefit-cost ratio (BCR) showed significant difference (P < 0.05) between
Conventional practice (T1M1) and CA technological options. The Conventional practice (T1M1)
ranked the least for the 4th cropping season out of the nine treatments tested, eight having CA
components. The Conventional practice (T1M1) and the best CA practice (T3M1) had BCR of
1.9 and 3.0, respectively. The results suggest that CA technologies, besides being able to sustain
crop productivity on steep lands, can bring about immediate economic benefit for cropping
seasons characterized with erratic rains and prolonged dry spells. |
