Biochar and compost enhance soil quality and growth of roselle (Hibiscus sabdariffa L.) under saline conditions

Abstract

Soil amendments may increase the slate tolerance of plants consequently; it may increase the opportunity of using saline water in agricultural production. In the present pot trial, the effects of biochar (BIC) and compost (COM) on roselle (Hibiscus sabdariffa L.) irrigated with saline water (EC = 7.50 dS m−1) was studied. Roselle plants were amended with biochar (BIC1 and BIC2) or compost (COM1 and COM2) at rates of 1 and 2% (w/w), as well as by a mixture of the two amendments (BIC1+). The experiment included a control soil without any amendments. Biochar and compost significantly enhanced the soil quality and nutrients availability under saline irrigation. Compost and biochar improved the degree of soil aggregation, total soil porosity and soil microbial biomass. BIC1 + COM1 increased the soil microbial biomass carbon and nitrogen over the individual application of each amendments and control soil. BIC1 + COM1 increased the activity of dehydrogenase and phosphatase enzymes. Growth of roselle plants including: plant height, shoot fresh and dry weight, and chlorophyll were significantly responded to the added amendments. The maximum sepal’s yield was achieved from the combined application of compost and biochar. All the investigated treatments caused remarkable increases in the total flavonol and anthocyanin. BIC1 + COM1 increased the total anthocyanin and flavonol by 29 and 17% above the control. Despite the notable improvement in soil and roselle quality as a result of the single addition of compost or biochar, there is a clear superiority due to mixing the two amendments. It can be concluded that mixing of biochar and compost is recommended for roselle plants irrigated with saline water.

Corn Cob-Derived Biochar Improves the Growth of Saline-Irrigated Quinoa in Different Orders of Egyptian Soils

“…The organic carbon compounds in biochar are more stable and resistant to the decomposition by soil microorganisms [23,34,41]. Besides improving nutrient retention, BC has a role in the improvement of the overall soil structure [41][42][43][44][45][46][47][48][49][50][51][52].…”

“…Supplying the soil with an adequate amount of nutrients and their uptake by plants is considered proof of the soil capacity and an increase in the use efficiency [50][51][52][53][54][61][62][63][64][65]. The application of BC has many additional benefits for plant nutrient cycling, high retention, leaching reduction, and increased use efficiency, thereby improving soil fertility [35].…”

“…Biochar as an organic amendment improves the level of soil organic matter, which helps to maintain water and nutrient retention, contributing to the sustainability of the cropping systems and higher nutrient use efficiency [34]. Moreover, biochar could store nutrients and be used as a slow-release fertilizer [50,51] thanks to its specific properties such as pore structure and functional groups [50,51,56,[66][67][68]. Some inorganic forms of N can be adsorbed to BC and minimize the emission of ammonia and nitrate leaching from soil [23].…”

“…Some inorganic forms of N can be adsorbed to BC and minimize the emission of ammonia and nitrate leaching from soil [23]. The addition of BC can potentially allow the slow release of nutrients to the plant roots and increase the nutrient use efficiency [23,34,51,52,69]. Owing to the internal reactive surface area of the soil-biochar matrix, the decrease in nutrient leaching is related to increased nutrient use efficiency via an increase in water-soluble nutrients and their retention and, consequently, their availability [23,52,57,70].…”

Effects of Biochar and Compost Applications on Soil Properties and Growth Performance of Amaranthus sp. Grown at Urban Community Garden

“…This shows that both biochar and compost either by stand-alone or in combination have ability to improve the growth performance of the plant. According to Liu et al (2021), the combination of the two amendments is more effective in increasing the plants development than applying each amendment separately. This is proved by the study conducted by Schulz, Dunst, & Glaser (2013) where biochar does not only help in accelerating plant growth, but it is also capable to increase the effectiveness of fertilizer particularly when incorporated with organic fertilizer like compost.…”