Biochar Effects on Bacterial Community and Metabolic Pathways in Continuously Cotton-Cropped Soil

Drought is one of the major abiotic stresses to sustainable agriculture and global food security. The present study was conducted to evaluate the integrated effect of algal biochar (BC) and plant growth-promoting rhizobacteria (PGPR) on growth and physiology of maize under deficit irrigations. A pot experiment with different combinations of algal BC and PGPR under three deficit irrigations [field capacity (FC), 75% FC and 50% FC] was performed using maize as test crop. There were three controls without application of algal BC and PGPR under each water deficit irrigation. Both algal BC and plant growth-promoting rhizobacterial inoculation mitigated negative effects of deficit irrigations on maize performance, especially when applied in combined form. Under 50% FC, combined application of algal BC and PGPR significantly increased fresh and dry weights of shoot and root and root length by 2.76, 5.94, 3.24, 13.82, and 4.06 times compared to control, respectively. In case of physiological and nutrient uptake parameters, the same treatment caused the maximum increase in comparison to control. Post-harvest soil analysis also showed a positive treatment effect compared to their respective control. The combined application of algal BC and PGPR could be an effective strategy to improve growth and physiology of maize under deficit irrigations.

Section: Discussionmentioning

confidence: 99%

Integrated Effect of Algal Biochar and Plant Growth Promoting Rhizobacteria on Physiology and Growth of Maize Under Deficit Irrigations

Ullah

Ditta

Khalid

et al. 2019

“…In this study, total soil bacterial DNA was extracted using the E.Z.N.A® Soil DNA Kit (OMEGA, USA) (Han et al 2019).…”

Section: Dna Extraction In Samples and High-throughput Sequencingmentioning

confidence: 99%

“…The PCR instrument was a BioRad S1000 (Bio-Rad Laboratory, CA, USA) (Gong et al 2019). The specificity test for the PCR amplification product was undertaken on 1.5% agarose gel and purified using the EZNA Gel Extraction Kit (Omega, USA) (Han et al 2019).…”

Section: Dna Extraction In Samples and High-throughput Sequencingmentioning

confidence: 99%

Effects of Short-Term Application of Chemical and Organic Fertilizers on Bacterial Diversity of Cornfield Soil in a Karst Area

Liu

Zhang

et al. 2020

Among karst mountain agricultural fertilization measures, the partial replacement of chemical fertilizers with organic fertilizers is important for protecting its vulnerable mountain environment and developing ecologically-friendly agriculture. In this study, we investigated the effects of short-term organic fertilizer application on the bacterial diversity of maize soil in karst areas and the potential of using organic fertilizer as a partial substitute for chemical fertilizers. Two maize fields with different parent materials in a karst region were selected for a short-term field control experiment using chemical fertilizer and organic fertilizer treatment, combined with the high-throughput sequencing method of 16S rDNA gene amplicons. (i) The soil physicochemical properties and bacterial diversity of different parent material soil are different, but the main dominant bacterial types are similar. (ii) Shortterm organic fertilizer treatment, rather than chemical fertilizer treatment, increased the bacterial richness significantly, especially for some functional bacteria (such as Nitrospira, Gemmatimonas). (iii) Analysis of the correlation between environmental factors and bacterial diversity indicated that soil pH and total P had the most significant effects on bacterial community structure (r = 0.91, p = 0.001; r = 0.33, p = 0.001). This study showed that it is an effective method to maintain a richer bacterial community and increasing the abundance of some functional bacteria by increasing organic fertilizers and reducing chemical fertilizers in the farm soil in karst regions, which could also be applied to other fragile agricultural ecosystems in the world.

“…Previous studies (Cayuela et al 2014;Han et al 2019;Nanda et al 2016;Yang et al 2019) reported that the application of biochar to soils has shown advantages in the growth of various crop production, namely through the improvement of soil biological activities, nutrients retention, water retention capacity, increase of pH value, and amount of soil organic matter. The soil used in the present study was collected in an agricultural field with high fertility (pH = 5.5, organic matter = 2.6%, high extractable P and K), which may explain the high LDW Leaf dry weight (g), SDW stem dry weight (g), IDW inflorescence dry weight (g), DW total plant dry weight (g), TFW total flower dry weight (g), TAW total achene dry weight (g)…”

Section: Cardoon Productivitymentioning

confidence: 99%

Effect of Biochar on Emission of Greenhouse Gases and Productivity of Cardoon Crop (Cynara cardunculus L.)

Barracosa

Cardoso

Marques

et al. 2020

Cardoon could be cropped for agro-environmental, industrial, and pharmaceutical purposes. The aim of this study was to assess the effects of biochar on emissions of nitrous oxide (N 2 O), carbon dioxide (CO 2), and methane (CH 4), and productivity of cardoon crop. A pot experiment was run outdoors from April to August 2018, with a cardoon plant per pot. The following four treatments, with four replicates each, were applied: control, soil only; mineral, soil amended with mineral fertilizer (2.5 g N m −2); biochar, soil amended with biochar (1 kg m −2); and mineral+biochar, soil amended with mineral fertilizer (2.5 g N m −2) and biochar (1 kg m −2). The morphological characteristics and biomass production of cardoon plants were evaluated, and the fluxes of N 2 O, CO 2 and CH 4 were measured by using the closed chamber technique. The application of biochar combined with mineral reduced N 2 O emissions by 36% and global warming potential (GWP) by 26% relative to mineral. However, the cumulative CO 2 and CH 4 emissions as well as yield-scaled GWP were not significantly different among amended soil treatments. Furthermore, the biomass production was increased by 50% by the application of biochar combined with mineral fertilizer relative to mineral. It was concluded that biochar combined with mineral fertilizer is recommended as a pathway mitigation for agro-environmental purposes, because it reduces the global warming potential and could increase the biomass production of cardoon plants.