Ensuring food security in small-scale farming requires improvement of
productivity of food crops to ensure access of food in local
communities. the objective of the sorghum-legume demonstration
trial was to demonstrate the performance of proven Sustainable
Agricultural Intensification (SAI) practices in terms of yield, soil
quality and labour efficiency. A farmers-led field trails were conducted
in Nachunyu and Mmumbu villages in Lindi district, Tanzania. The SAI
technologies validated include: i) Treatment 1: Conventional
tillage – farmers practice, consisting of hand hoe cultivation, residue
were removed, no herbicides applied (hand hoe weeding) and continuous
sorghum ii) Treatment 2: Conservation tillage dibble stick,
retention of crop residues but no herbicide use (traditional weeding), and
cropping system of continuous sorghum, applied fertilizers and no burning
of residues; iii) Treatment 3: Conservation tillage using dibble stick,
retention of crop residues, applied herbicide immediately after planting ,
but continuous sorghum, applied fertilizer (NPS) and no burning of
residues; iv) Treatment 4: Conservation agriculture with legume-sorghum
rotation, tillage dibble stick, retention of crop residues, apply
herbicide roundup soon after planting followed by traditional hand hoe
weeding when needed after crop germination, apply fertilizers (NPS),
started with sorghum in season one (1) 2017/18. Soil samples
were collected before the trials and after the trials. Data collected
includes grain yields and residue biomass. In both seasons, crop yield
and biomass were collected during harvest in a 6-meter square area in each
plot. All legume grains were weighed after de-shelling and weighed. A sub
sample of grains (sorghum and legumes) were taken and transported to SUA
to determine moisture content and the grain yield was adjusted to 14 to
13% moisture content. In 2017-2018 no sorghum grain yield was recorded as
all grains were damaged by birds, hence only biomass yield was recorded.
In 2018-2019 season, no sorghum yield was recorded due to poor germination
of sorghum, which led to no crop establishment in Hamasa demonstration
plot at Nachunyu village and birds damage in Mkombozi and Hiari
demonstration plot. In the first season 2017-18 a regional average yield
was collected from published Agricultural Statistics while in 2018-19
season, farmers in Lindi were interviewed to report their yield of crops
harvested in 2018-19 season. Composite
soil samples were collected before planting at 20 cm depth in each
experimental plot. A composite soil sample was obtained by mixing 5
samples randomly collected from the farm. In each farm two composite
samples were collected. The composite soil samples were placed in a clean
plastic bag, transported to Soil Science lab at SUA Morogoro. At the lab,
the soil samples were air dried, ground to pass through 2-mm sieve for
physical and chemical analysis. The samples were analysed as summarised in
Table 3.3. Before planting for second season 2018-2019, composite soil
samples were taken from each plot, transported to SUA Soil Science lab for
determination of soil pH, OC, Total N, available P, CEC and exchangeable
bases using same methods as in Table
3.3. Tabel 3.3: Soil analysis methods
Soil parameter
Methods
Reference
Texture
Bouyoucos hydrometer
method Day
(1965) pH (H2O)
pH meter
McLean, (1986)
Organic Carbon (%)
Walkley and Black
(1934) Total N (%)
Kjeldahl procedure
Bremner and Mulvaney,
(1982) Ava. P (mg kg-1)
Bray I /Olsen
method
CEC (cmolc
kg-1) NH4Ac saturation and
distillation-Titration Chapman (1965)
K+
(cmol kg-1) NH4Ac saturation and flame
photometer Thomas (1986)
Mg2+
(cmol kg-1) NH4Ac saturation and atomic
photometer Thomas (1986)
Ca2+
(cmol kg-1) NH4Ac saturation and atomic
photometer Thomas (1986)
Na+
(cmol kg-1) NH4Ac saturation and flame
photometer Thomas (1986)
* CEC: Cation Exchange capacity, PBS: Percent
base saturation MS word and MS Excel