Journal Article
Low, erratic rainfall amounts and restricted accessibility of chemical fertilizer
for rural farmers in developing countries may have negative effects on crop
production. Agricultural methods like biochar applications, fertilizer microdosing and tied ridging can help to mitigate these constraints, but have rarely
been studied in combination and under varying water availability. A field trial
was conducted in split-plot design over two contrasting cropping seasons in
2016 and 2017 in Tanzania to study the effect of these agricultural methods on
maize grain yield, biomass, leaf area index, plant height and soil moisture
content. In both seasons each with contrasting irrigation frequencies, fertilizer
microdosing increased the grain yield of maize. Biochar alone affected the
yield only at high application rates (10 t/ha) and low irrigation frequency.
However, when combined with fertilizer microdosing the yield effect of biochar was more pronounced. For example, combining 5 t/ha biochar with
fertilizer microdosing under flat tillage increased yield by 170% compared to
the control without biochar and fertilizers. Tied ridges increased soil moisture
content and tended to increase maize yield compared to flat tillage, whereas
biochar application resulted in significantly higher soil moisture contents.
Fertilizer microdosing with biochar application can be recommended to
improve maize yields mainly under flat tillage.