Abstract: The application of biochar to soils is becoming more and more common. Its application which is generally reported to improve the physical, chemical, and biological properties of soils, has an indirect effect on soil health and increased crop yields. However, many of the previous results are highly variable and dependent mainly on the initial soil properties, biochar characteristics, and production conditions. In this study, two biochars which are biochar II (BC II) derived from a blend of paper sludge and wheat husks and biochar 005 (BC 005) derived from sewage sludge with a KCl additive, are used, and the physical and chemical properties of BC II are characterized. To determine the potential impact of salt stress and toxic and volatile substances, the second part of this study focused on the effect biochars have on germination of salad (Lactuca sativa L.), barley (Hordeum vulgare), and cress (Lepidium sativum) respectively. Our results indicate that Biochar II showed some unique properties compared to the soil, such as high EC, high content of K, Na, Mg, and low content of heavy metals. Concerning salad and barley germination test, no negative effect of BC II and BC 005 was observed. However, a negative effect of BC 005 at 8% level was revealed. The test of the effect of volatile substances on germination of cress revealed a positive effect of BC II, while a negative effect was observed for BC 005. Moreover, the water holding capacities of biochar-sand mixtures increased with increasing biochar application. Collectively, BC II could be safely used for agriculture and could provide the potential for a better plant growth.
Abstract: This study was aimed to investigate the effect of
various organic supplements on growth and development of
Dendrobium discolor’s protocorms and seedlings growth of
Dendrobium Judy Rutz. Protocorms of Dendrobium discolor with 2.0
cm. in diameter and seedlings of Dendrobium Judy Rutz at the same
size (0.5 cm. height) were sub-cultured on Hyponex medium
supplemented with cow milk (CM), soy milk (SM), potato extract
(PE) and peptone (P) for 2 months. The protocorms were developed
to seedlings in all treatments after cultured for 2 months. However,
the best results were found on Hyponex medium supplemented with
P was the best in which the maximum fresh and dry weight and
maximum shoot height were obtained in this treatment statistically
different (p ≤ 0.05) to other treatments. Moreover, Hyponex medium
supplemented with P also stimulated the maximum mean number of
5.7 shoots per explant which also showed statistically different (p ≤
0.05) when compared to other treatments. The results of growth of
Dendrobium Judy Rutz seedlings indicated the medium
supplemented with 100 mL/L PE enhanced the maximum fresh and
dry weigh per explants with significantly different (p ≤ 0.05) in fresh
weight from other treatments including the control medium without
any organic supplementation. However, the dry weight was not
significantly different (p ≤ 0.05) from medium supplemented with
SM and P. There was multiple shoots induction in all media with or
without organic supplementation ranging from 2.6 to 3 shoots per
explants. The maximum shoot height was also obtained in the
seedlings cultured on medium supplemented with PE while the
longest root length was found in medium supplemented with SM.