Document Type : Research Paper - Sustainable food and Farming
Authors
1 Don't have
2 University of Guilan
Abstract
Introduction: Silicon dissolved in the soil in the form of H4SiO4 is absorbed by rice roots. A paddy field absorbs about 300 kg of silicon from the soil with 5 tons of paddy per hectare. Critical limit of silicon in the tillering and ripening stages of rice, in the stem and flag leaf, respectively, is 5% of dry weight. Sufficient silicon in the stem reduces the probability of rice falling which increases the cost of harvesting.
Materials and methods: This research was carried out in University of Guilan in the form of a completely randomized design with 13 treatments and 3 replications with aim of investigating effect of adding silica levels from four sources to paddy soil on height, diameter, number of nodes and silica amount in stem. Silica extracted from paddy husk, husk ash, husk powder and siliceous fertilizer of Behsan company were used. The experiment was carried out in 39 pots containing paddy soil, the implementation and effectiveness of four substances containing silica on the height, stem diameter, number of nodes and the amount of silica in the stem and leaves were investigated.
Findings: In the first measurement, there was no significant difference between the 13 treatments in terms of stem height. It seems that silicon needs a longer time to affect the height of the stem in rice. By increasing the duration of applying silica levels to the soil, the height of the stem in the S3 treatment reached from 15 to 83 cm.During growth, the average number of nodes in the S3 treatment increased from 3.66 to 7.33 and in the C3 treatment from 3.33 to 6.66, which statistically shows a significant difference between the S3 treatment and all treatments. At the end of the vegetative growth, the diameter of the stem in control and S3 and C3 treatments was 2.63, 4.98 and 4.97 mm, respectively, which have a significant difference. The amount of silicon absorbed and transferred to the stem was the best in the S3 and C3 treatments, and there is a significant difference between the treatments in the stem. In July, the amount of silicon in the stem in the plant treated with silica synthesized from paddy husk (S3) was 7.06%, in the treatment with commercial siliceous fertilizer (C3) it was 6.04% and in the control treatment (B) it was 1.94%. In August, there was a significant difference in the amount of silicon in 13 treatments.The highest value in the stem in treatment (S3) is equal to 10.79%, in treatment C3, 8.03% and in control (B), it is 3.69%. In September, the amount of silicon in the stem decreased.
The highest amount of silicon in September in the stem (2.1%) was related to treatment S3, which is statistically significant with treatments C1 and B, but is in the same range as the rest of the treatments. The next treatment, i.e. the highest level of commercial silica (C3) with 2.06 percent of silicon after synthesized silicon, which is statistically significantly different only from treatment (C1, B). All treatments except treatment (C1) have significant differences only with the control (B). The optimal amount of silicon in rice stem is 8-10% and if it is less than 5%, rice is deficient in silicon.S3 and C3 treatments were identified as the best treatments in terms of plant height, stem diameter, number of internodes, and internodes length.
Conclusion: According to the amount of silicon in the stem and leaf in three stages of growth, it seems that with the increase in age and size of the plant, the amount of silicon in these two organs decreases and this decrease is more in the leaf than in the stem. It can be said that with the beginning of reproductive growth, silicon is transferred from stem and leaf to rice husk. According to the results, adding 0.24 grams of extracted silicon to 3 kg of soil was the best treatment, followed by commercial siliceous fertilizer, which had the most positive effect. Between the treatment of paddy husk ash and rice husk powder, ash can be introduced as more suitable because for most of the characteristics studied in this experiment, ash was more effective compared to powder.
Keywords
- "؛ Agricultural residue"؛ Silica fertilizer"؛ Silica content in stem"؛ Silicon extraction"؛
- "؛ Rice husk"
Main Subjects
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