MAIZE is one of the important crops in Egypt that can be grown successfully on light textured
soils. Although amending these soils with biochar may increase the efficiency of nutrient
utilization by plants; yet both biochars and Egyptian soils exhibit alkaline nature. The current
studyinvestigates to what extent can biochar modified with either sulfuric acid or with elemental
sulfur(S)(an acidifying agent)surpass the effect of adding biochar solely to a sandy soil (93% sand),
with emphasis onthe increase of N and K availability in soil and their uptake and distribution within
maize plants. A greenhouse experiment was conducted in a complete randomized design comprising
(1) no biochar application (control), (2) biochar applied at a rate of 10g kg-1, (3) biochar (10g kg-1) +
elemental sulfur (2 g kg-1) and (4) biochar acidified with H2SO4 (10g kg-1). These treatments were
added 2 weeks prior to maize sowing. Thereafter, all pots were planted for 60 days and soil moisture
was kept at 80% of the water holding capacity throughout the period of this investigation. Results
indicate that only “acidified bioachar” and “biochar+S” treatments raised significantly SO42- content
in soil; thus they both decreased soil pH. On the other hand, application of non-acidified biochar
solely raised soil pH.All treatmentsdecreased soil bulk density and improved soil moisture
characteristics (field capacity, permanent welting point and available water content). This, in turn,
significantly raisedN- and K- available contents in soil and consequently increasedtheir uptake by
maize plants. In particular, the non-acidified biochar recorded the highest increases in N-uptake by
plants while acidified biochar recorded the highest K uptake followed by biochar+S. Overall, all
biochars significantly boosted root and shoot biomass, especially the acidified one, followed by the
combined biochar+S treatment. Furthermore, these treatments recorded the highest N and K
utilization efficiencies by maize plants. In conclusion, using elemental sulfur with biochar may
effectively increase the efficiency of applied biochar via increasing nutrient use efficiencies; yet this
dual application might not be as efficient as acidified biochar for enhancing plant growth.
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