Biochar Coating as a Cost-Effective Delivery Approach to Promoting Seed Quality, Rice Germination, and Seedling Establishment.

The application of high-quality seeds ensures successful crop establishment, healthy growth, and improved production in both quantity and quality. Recently, biochar-based seed coating has been recognized as a new, effective, and environmentally friendly method to enhance seed quality, seedling uniformity, and nutrient availability. To study the impact of biochar coating on the surface mechanical properties of coated seeds, rice emergence and growth, and related physical and physiological metabolic events, laboratory experiments were performed on two water-saving and drought-resistance rice (WDR) varieties (Huhan1512 and Hanyou73) using biochar formulations with varying contents (20%-60%). The results showed that the appropriate concentration of biochar significantly improved emergence traits and seedling performance of the two rice varieties, compared to the uncoated treatment, and that the optimal percentage of biochar coating was 30% (BC30). On average, across both varieties, BC30 enhanced emergence rate (9.5%), emergence index (42.9%), shoot length (19.5%), root length (23.7%), shoot dry weight (25.1%), and root dry weight (49.8%). The improved germination characteristics and vigorous seedling growth induced by biochar coating were strongly associated with higher water uptake by seeds, increased α-amylase activity and respiration rate, and enhanced accumulation of soluble sugar and soluble protein. Moreover, the evaluation results of mechanical properties related to seed coating quality found that increasing the proportion of biochar in the coating blend decreased the integrity and compressive strength of the coated seeds and reduced the time required for coating disintegration. In conclusion, biochar coating is a cost-effective strategy for enhancing crop seed quality and seedling establishment.

Preparation of low-cost functionalized diatomite and its effective removal of ammonia nitrogen from wastewater.

A low-cost functionalization method was used to treat diatomite, and an efficient adsorbent for ammonia nitrogen was prepared by optimizing the functionalization conditions. The functionalized diatomite (DTCA-Na) was characterized by SEM, EDS, BET, XRD, FT-IR, and TG. The results demonstrate that DTCA-Na has excellent adsorption performance after being modified with H2SO4 (60.00 wt.%), NaCl (5.00 wt.%), and calcination at 400 °C for 2 h. While studying the effect of adsorption factors on the removal of ammonia nitrogen, the kinetic and thermodynamic behaviors in the adsorption process were discussed. The removal efficiency of the simulated wastewater with the initial ammonia nitrogen concentration of 10.00 mg L-1 by the DTCA-Na was more than 80% when the contact time was 60 min, pH was 6-10, the dosage of adsorbent was 1.00 g, and the temperature was 25 °C. The adsorption process of ammonia nitrogen was conformed to the pseudo-first-order and Langmuir isothermal model. The removal efficiency of ammonia nitrogen was still above 80% after 5 times adsorption-desorption experiments. The DTCA-Na has a brighter prospect of application in the field of ammonia nitrogen wastewater treatment due to its excellent adsorption performance and low-cost advantage.

Biochar Coating Is a Sustainable and Economical Approach to Promote Seed Coating Technology, Seed Germination, Plant Performance, and Soil Health.

Seed germination and stand establishment are the first steps of crop growth and development. However, low seed vigor, improper seedbed preparation, unfavorable climate, and the occurrence of pests and diseases reduces the germination rate and seedling quality, resulting in insufficient crop populations and undesirable plant growth. Seed coating is an effective method that is being developed and applied in modern agriculture. It has many functions, such as improving seed vigor, promoting seedling growth, and reducing the occurrence of pests and diseases. Yet, during seed coating procedures, several factors, such as difficulty in biodegradation of coating materials and hindrance in the application of chemical ingredients to seeds, force us to explore reliable and efficient coating formulations. Biochar, as a novel material, may be expected to enhance seed germination and seedling establishment, simultaneously ensuring agricultural sustainability, environment, and food safety. Recently, biochar-based seed coating has gained much interest due to biochar possessing high porosity and water holding capacity, as well as wealthy nutrients, and has been proven to be a beneficial agent in seed coating formulations. This review presents an extensive overview on the history, methods, and coating agents of seed coating. Additionally, biochar, as a promising seed coating agent, is also synthesized on its physico-chemical properties. Combining seed coating with biochar, we discussed in detail the agricultural applications of biochar-based seed coating, such as the promotion of seed germination and stand establishment, the improvement of plant growth and nutrition, suitable carriers for microbial inoculants, and increase in herbicide selectivity. Therefore, this paper could be a good source of information on the current advance and future perspectives of biochar-based seed coating for modern agriculture.

How Biochar Affects Nitrogen Assimilation and Dynamics by Interacting Soil and Plant Enzymatic Activities: Quantitative Assessment of 2 Years Potted Study in a Rapeseed-Soil System.

The amendment of biochar has been proposed to improve soil fertility and crop yield. However, consolidated information lacks explaining the role of biochar on soil and plant enzymatic activities involved in nutrients cycling in soil and accumulation in plants improving utilization of applied inorganic fertilizer and crop growth. In the current study, we evaluated the integral effects of biochar levels (B0:0, B15:15, B3:30, and B60:60 t ha-1) and nitrogen fertilizer levels (N0:0, N75:75, N225:225, and N450:450 kg ha-1) on soil physicochemical properties, enzymatic activities, nitrogen use efficiency (NUE) and grain yield of rapeseed for 2 years in the pots during 2020 and 2021. The findings revealed that compared to control (B0 + N0), a combination of B30 + N450 increased soil urease activity by 73 and 75%, and B60 + N450 increased activities of soil catalase by 17 and 16%, and B60 + N225 increased alkaline phosphatase by 17 and 19%, respectively, in the first and second year. Moreover, a single application of high nitrogen at 450 kg ha-1 reduced the activities of plant nitrogen metabolism-related enzymes, however; the integration of biochar at 30 t ha-1 compensated the high nitrogen toxicity and improved the activities of nitrate reductase (NR), nitrite reductase NIR, glutamate synthase (GS) and glutamine synthetase (GOGAT) at seedling stage (SS) and flowering stage (FS) in both years. The integration of biochar at 30 t ha-1 with nitrogen at 450 kg ha-1 induced synergetic effects on rapeseed growth through sorption of excessive nitrogen in soil and significantly improved the plant height up to 11 and 18%, pods plant-1 39 and 32% and grain yield plant-1 54 and 64%, respectively, during the first and second year. Moreover, biochar at 15 t ha-1 along with nitrogen at 225 kg ha-1 resulted in the highest NUE of 29% in both years suggesting that biochar can also offset the deficiency of lower nitrogen. This study highlighted the ameliorative effect of biochar suppressing high nitrogen toxicity and decreasing lower nitrogen deficiency effects on rapeseed growth by improving nitrogen use efficiency via enhancing soil conditions, enzymatic activities and soil nitrogen utilization potential and thus improving rapeseed growth and yield.

Nomogram for short-term outcome assessment in AChR subtype generalized myasthenia gravis.

BACKGROUND: An accurate prediction for prognosis can help in guiding the therapeutic options and optimizing the trial design for generalized myasthenia gravis (gMG). We aimed to develop and validate a predictive nomogram to assess the short-term outcome in patients with the anti-acetylcholine receptor (AChR) subtype gMG. METHODS: We retrospectively reviewed 165 patients with AChR subtype gMG who were immunotherapy naïve at the first visit from five tertiary centers in China. The short-term clinical outcome is defined as the achievement of minimal symptom expression (MSE) at 12 months. Of them, 120 gMG patients from Huashan Hospital were enrolled to form a derivation cohort (n = 96) and a temporal validation cohort (n = 24) for the nomogram. Then, this nomogram was externally validated using 45 immunotherapy naïve AChR subtype gMG from the other four hospitals. Multivariate logistic regression was used to screen independent factors and construct the nomogram. RESULTS: MSE was achieved in 70 (72.9%), 20 (83.3%), and 33 (73.3%) patients in the training, temporal validation, and external validation cohort, respectively. The duration ≤ 12 months (p = 0.021), ocular score ≤ 2 (p = 0.006), QMG score > 13 (p = 0.008), and gross motor score ≤ 9 (p = 0.006) were statistically associated with MSE in AChR subtype gMG. The nomogram has good performance in predicting MSE as the concordance indexes are 0.81 (95% CI, 0.72-0.90) in the development cohort, 0.944 (95% CI, 0.83-1.00) in the temporal validation cohort, and 0.773 (95% CI, 0.63-0.92) in the external validation cohort. CONCLUSION: The nomogram achieved an optimal prediction of MSE in AChR subtype gMG patients using the baseline clinical characters.

Identification of gene modules associated with drought response in rice by network-based analysis.

Understanding the molecular mechanisms that underlie plant responses to drought stress is challenging due to the complex interplay of numerous different genes. Here, we used network-based gene clustering to uncover the relationships between drought-responsive genes from large microarray datasets. We identified 2,607 rice genes that showed significant changes in gene expression under drought stress; 1,392 genes were highly intercorrelated to form 15 gene modules. These drought-responsive gene modules are biologically plausible, with enrichments for genes in common functional categories, stress response changes, tissue-specific expression and transcription factor binding sites. We observed that a gene module (referred to as module 4) consisting of 134 genes was significantly associated with drought response in both drought-tolerant and drought-sensitive rice varieties. This module is enriched for genes involved in controlling the response of the plant to water and embryonic development, including a heat shock transcription factor as the key regulator in the expression of ABRE-containing genes. These results suggest that module 4 is highly conserved in the ABA-mediated drought response pathway in different rice varieties. Moreover, our study showed that many hub genes clustered in rice chromosomes had significant associations with QTLs for drought stress tolerance. The relationship between hub gene clusters and drought tolerance QTLs may provide a key to understand the genetic basis of drought tolerance in rice.