Abstract:
Maize is cultivated as a second crop next to rice in tropical
conditions and depends on chemical fertilizers (CF) which contribute to
detrimental ecological consequences. As a recent development, formulated
fungal-bacterial biofilms (FBBs) of nitrogen fixing bacteria and fungi have
shown potentials to be used as biofertilizers in agriculture, termed biofilmed
biofertilizers (BFBFs). Therefore, current study was focused on the effect of
developed BFBFs on plant growth and soil nutrient availability under CF
reduction. A greenhouse soil pot experiment was conducted for 60 days
using treatments; 100% CF (Recommended dose by the Department of
Agriculture), 50% CF, 50% CF + BFBF1 and 50% CF + BFBF2, two BFBFs
formulations. Plant photosynthetic efficiency and total plant dry weight
were measured after 45 and 60 days of plant growth, respectively, and soil
available ammonium (𝑁𝐻4
+), nitrate (𝑁𝑂3
−), phosphate (𝑃𝑂4
3−) and soil
organic carbon (SOC) were measured following standard methods at 60 days
of plant growth. Initial availabilities of 𝑁𝐻4
+, 𝑁𝑂3
−, and 𝑃𝑂4
3− were 42.76,
15.08, and 2.41 µg/g soil, respectively. Results showed that 50% reduction of
CF did not affect plant growth, since nutrient use efficiency was presumably
improved by the BFBF. Enhanced plant photosynthetic efficiency under
BFBF application was possibly due to sufficient chlorophyll content in plant
leave, caused by adequate supply of 𝑁𝐻4
+. In contrast, reduced availability of
𝑃𝑂4
3− (0.24 µg/g soil) under BFBF2 could be due to plant uptake, possibly
through the enhanced root growth. Thus, BFBF can reduce CF input in
maize agriculture for a sustainable system. Further experiments under field
conditions are however needed to evaluate their potential use in maize
cultivation.
