Plant Nutrition, Soil Fertility and Fertilizers
Mehri Bazi abdoli; M Barani; abdolamir Bosatni; Taleb Nazari
Abstract
Introduction Various biomass sources such as crop residues have been proposed as feedstock for biochar production . Meanwhile, a large quantity of crop residues (rice) is produced as waste and they are either burnt or piled and abandoned at some locations in the fields. Burning of crop residues is resulting ...
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Introduction Various biomass sources such as crop residues have been proposed as feedstock for biochar production . Meanwhile, a large quantity of crop residues (rice) is produced as waste and they are either burnt or piled and abandoned at some locations in the fields. Burning of crop residues is resulting in substantial loss of nutrients, and may lead to air pollution and human health problems . An alternative approach is to apply crop residues to soil in the form of biochar. Bioavailability of nutrients exclusively micronutrients (Fe, Zn) isa serious problem in soils having high pH which ends in crops yield to decline and ultimately can lead to malnutrition in humans. The biochar modification with acid may increase the solubility of nutrients (P, , Fe, Zn, Cu,,Mn) present in biochar, thereby significant improvement in mineral nutrition of plants grown in calcareous soils. In the other hand, One of the ways to use and exploit saline lands is to use salinity-tolerant cultivars, such as the Quinoa (Chenopodium quinoa) plant. It is known that biochar increases soil pH, which may result in less availability of phosphorus and other micronutrients, such as Fe, Zn, and Mn, in alkaline and calcareous soils. Therefore, modifying biochar with acids can increase the availability of nutrients in biochar for different plants grown in calcareous soils. The objection of this study is to investigate the effect of normal biochar and acid-modified biochar from rice residues on the yield and yield components of quinoa plants (Gizavan number) in a calcareous soil affected by salt.Materials and Methods The soil used in the study was collected from 0-30 cm depth which passed through via 2-mm sieve after air-drying and its chemical and physical properties were determined. To achieve the aim of this study, the factorial experiment was carried out in a completely randomized design in 4 replications. Factors include 3 types of rice biochar (unmodified, modified by pre-acidic method and modified by post-acidic method) and different levels of biochar (0, 2, and 5% by weight). Then 10 quinoa seeds were planted in each pot at 2 cm depth which after the plant emerging and greening declined to 3 plants in each pot. The pots were randomly moved twice a week during growth to eliminate environmental effects. Irrigation and weeding operations were done by hand. After the end of the growth period (187 days), the plants were harvested. So vegetative growth parameters and yield components including shoots fresh and dry weight, plant height, stem diameter, panicle length, number of leaves, number of lateral branches, and 1000 grain weight were measured and then biological yield and harvest index were determined. The statistical results of the data were analyzed using SAS software (9.4) and the LSD test (at 5% level) was used for comparing the mean values.Results and Discussion As a result of adding biochar to soil, it becomes alkaline. Chemical modification of biochar using strong acids can reduce soil pH and improve the fertility of calcareous soils and increase vegetative parameters and yield components of quinoa. Based on the obtained results, the interaction effect of different types and levels of biochar on all investigated traits was significant at the level of 1%. The results showed that the highest height, fresh and dry weight, panicle length, number of lateral branches, and stem diameter were related to the 5% post-acidic rice biochar treatment and the lowest value was related to the control treatment. furthermore, the results showed that the highest amount of plant dry weight of 8.82 gr/pot, the height of 77.50 cm, and 1000 seed weight of 17.3 gr/pot was obtained from the treatment of 5% post-acidic rice biochar, compared to the treatment of 5% Unacidified rice biochar had an increase of (81.97), (56.77), (32.17) and (7.06) percent respectively. As a result of the high dry weight of shoots and the 1000 seed weight, the 5% post-acidic rice biochar treatment provided the highest biological yield at 16.05 and harvest index at 45.03.Conclusion Under the conditions of this study, acid-modified biochars (post-acidic and pre-acidic) enhanced vegetative growth characteristics and yield components of quinoa plants in calcareous soils affected by salt. Therefore, it is recommended to prepare biochar from acidic sources or to modify it with post-acidic and pre- acidic methods.
