Biochars can be used as soil amendments for improving soil properties and crop yield. The objective of this research was to
study the plant growth, yield, yield components, and seed quality, including nutrients and heavy metals (Pb, Cd, and Hg), in
the soybean plant (
Glycine
max
[L.] Merr.) and soil. The experiment was conducted from September 2010 to January 2011
in a greenhouse located in the Dan Khun Thot District, Nakhon Ratchasima Province, Thailand. The research comprised
six treatments with four replicates in a completely randomized design. Quail litter biochar (QLB) at rates of 0, 24.6, 49.2,
73.8, 98.4 and 123 g per pot mixture were provided to soybean cv. Chiang Mai 60. The results showed that QLB could be
used as a soil fertility improvement and amendment for soybean production with an optimum rate of 98.4 g per pot mixture,
which gave the best performance in terms of the number of nodes, height, DM accumulation, total yield, and seed quality.
After the experiment, the nutrient contents in the soil increased as the QLB content increased, but the heavy metal residues
in the leaves and seeds did not change. However, QLB at levels higher than 98.4 g per pot mixture is not advisable because
QLB is alkaline in nature, which may affect soil pH.