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nutrients mainly from soil reserve. Therefore, soil fertility mining happens when
farmers feed all crop residues to livestock without the return of manure to the farm.
The smallholder farmers, therefore, should be trained on the improvement of plant
nutrition and feeding of crop residues to reduce depletion of soil fertility. Except
for Zn concentrations, all other mineral concentrations and nitrogen content were
low to very low for dairy cattle fodder, and supplementations of nitrogen and mineral premix are important in optimising milk production in cereal crop residuebased diets.
1 Introduction
1.1 Importance of Maize and Rice on Food Security
in Tanzania
Maize and rice account for 31% and 13%, respectively, of the total food production
in Tanzania (WEMA 2010). Nearly 75% and 60% of the country’s population consume maize and rice, respectively. The per capita consumption of maize and rice
averages to approximately 74.5 and 16.5 kg/person/year (FAOSTAT 2012; PASS
2012), respectively. Maize provides 60% of dietary calories and more than 35% of
utilisable protein to the Tanzanian population (USDA 2017).
Maize and rice crops are vital food and cash crops grown in almost all regions
in the country (Mdoe et al. 2015; RATES 2003; USDA 2012). Maize crop comprises 45% of the cultivated area, and its production accounts for more than 70%
of the cereal produced in Tanzania (USDA 2017). Since farmers sell about 40% of
their maize locally and to neighbouring countries, it is a significant source of
income for the majority of smallholder farmers in the southern highlands of
Tanzania.
Nearly 90% of the two cereal crops are produced by smallholder farmers, with
an average farm size ranging from 0.5 to 2 ha and keeping one to three cattle for
milk production, draught power and manure for their farms. Farmers grow maize in
various agro-ecologies ranging from near sea level to 2000 m above sea level
depending on the variety. It is widely grown from infertile sandy soils towards the
eastern and northern to loam-clay soils in the southern part of the country (Mdoe
et al. 2015; USDA 2017). Despite its importance to the food security, maize productivity in the country has been persistently low (about 1.6 Mg/ha) because of lack of
skill and capital for sustainable intensification of the crop (Mtengeti et al. 2015).
Most rice is grown by smallholder farmers under rain-fed conditions, but some
farmers grow 2–2.5 ha under irrigation schemes along the river valleys and alluvial
plains with permanent water supplies. Mean yield in smallholder farms is generally
low, ranging from 1.6 to 2.4 Mg/ha. With irrigation, production of rice can be more
than 5 Mg/ha (USDA 2012).
E. J. Mtengeti et al.
nutrients mainly from soil reserve. Therefore, soil fertility mining happens when
farmers feed all crop residues to livestock without the return of manure to the farm.
The smallholder farmers, therefore, should be trained on the improvement of plant
nutrition and feeding of crop residues to reduce depletion of soil fertility. Except
for Zn concentrations, all other mineral concentrations and nitrogen content were
low to very low for dairy cattle fodder, and supplementations of nitrogen and mineral premix are important in optimising milk production in cereal crop residuebased diets.
1 Introduction
1.1 Importance of Maize and Rice on Food Security
in Tanzania
Maize and rice account for 31% and 13%, respectively, of the total food production
in Tanzania (WEMA 2010). Nearly 75% and 60% of the country’s population consume maize and rice, respectively. The per capita consumption of maize and rice
averages to approximately 74.5 and 16.5 kg/person/year (FAOSTAT 2012; PASS
2012), respectively. Maize provides 60% of dietary calories and more than 35% of
utilisable protein to the Tanzanian population (USDA 2017).
Maize and rice crops are vital food and cash crops grown in almost all regions
in the country (Mdoe et al. 2015; RATES 2003; USDA 2012). Maize crop comprises 45% of the cultivated area, and its production accounts for more than 70%
of the cereal produced in Tanzania (USDA 2017). Since farmers sell about 40% of
their maize locally and to neighbouring countries, it is a significant source of
income for the majority of smallholder farmers in the southern highlands of
Tanzania.
Nearly 90% of the two cereal crops are produced by smallholder farmers, with
an average farm size ranging from 0.5 to 2 ha and keeping one to three cattle for
milk production, draught power and manure for their farms. Farmers grow maize in
various agro-ecologies ranging from near sea level to 2000 m above sea level
depending on the variety. It is widely grown from infertile sandy soils towards the
eastern and northern to loam-clay soils in the southern part of the country (Mdoe
et al. 2015; USDA 2017). Despite its importance to the food security, maize productivity in the country has been persistently low (about 1.6 Mg/ha) because of lack of
skill and capital for sustainable intensification of the crop (Mtengeti et al. 2015).
Most rice is grown by smallholder farmers under rain-fed conditions, but some
farmers grow 2–2.5 ha under irrigation schemes along the river valleys and alluvial
plains with permanent water supplies. Mean yield in smallholder farms is generally
low, ranging from 1.6 to 2.4 Mg/ha. With irrigation, production of rice can be more
than 5 Mg/ha (USDA 2012).
E. J. Mtengeti et al.