Use of locally available organic and inorganic resources to restore sodic soils in northern Tanzania
Keywords:
Available water capacity, electrical conductivity, exchangeable sodium percentage, farm yard manure, gypsum, infiltration rate, maize, osmotic potential, salts, sodium.Abstract
Sodic soils could produce useful maize (Zea mays L.) crop yields if reclaimed by appropriate techniques. A field
experiment was conducted on the selected lowlands of northern Tanzania using a randomised complete block
design to study the effectiveness of supplying gypsum (CaSO4.2H2O) or farmyard manure (FMY) alone or both
mixtures on the reclamation of a sodic soil. Sodic soil and FYM were characterised to establish their quality
status before any intervention was introduced. The treatment used included: control, FYM alone (25 t ha-1), FYM
(25 t ha-1) combined with gypsum (12.5 t ha-1) and gypsum alone (12.5 t ha-1). The treatments were replicated four
times. Selected numbers of soil physical and chemical properties were then investigated. Results from our
study revealed that regardless of the amendments used, maize yield and all soil physical and chemical
properties tested were improved in Year 2 (Y2) relative to Year 1 (Y1). Our results also showed that combining
FYM with gypsum significantly (p 0.05) improved pH, electrical conductivity of the saturated paste (ECe),
exchangeable sodium percentage (ESP), infiltration rate (IR), osmotic potential (OP) and available water capacity
(AWC) of sodic soils. The FYM was the second- best treatment in the improvement of pH, ESP and EC whereas
gypsum was second in the improvement of ESP, IR and maize yield.
