● Analyzes the current situation of planted forests construction in China.

Tree plantations are an important forest resource that substantively contributes to climate change mitigation and carbon sequestration. As the area and standing volume of tree plantations in China have increased, issues such as unreasonable structure, low productivity, limited ecological functionality and diminishing ecological stability have occurred, which hinder the ability of tree plantations to enhance carbon sequestration. This study outlined the trajectory of carbon sequestration and its associated benefits in tree plantations by examining the current state of tree plantation establishment and growth, elucidated the strategies for advantages of carbon sequestration and climate change mitigation in planted forests, and summarized the existing problems with tree plantations. This paper underscores the pressing need for concerted efforts to boost carbon sequestration within planted forests and proposes management and development strategies for Chinese tree plantations. In the future, it will be necessary to apply scientific theories to practice and develop multi-objective management optimization models for the high-quality development of tree plantations. This will involve establishing a cohesive national carbon trading market, improving the prediction of carbon sequestration, and identifying priority zones for afforestation and reforestation, to better serve China’s national strategy for achieving peak carbon and carbon neutrality.

● The main impediments to low-carbon development of livestock sector are recognized.

Rapid growth and a vast transition of Chinese livestock industry driven by economic incentives make it become an important contributor on climate change over the last four decades. This study first analyzes the evolving low-carbon livestock development policies and regulations, then an assessment and explanations of the achievements and non-achievements are provided. The findings reveal that China began to pay attention to low-carbon development policy starting in the early 1990s. However, only after the cyclic and green concept became the main sustainable development policy, China began to move seriously toward low-carbon livestock development. Several policy instruments were introduced, including moderate scale, feed optimization, manure resource utilization, facility and equipment allocation rate, energy conservation and substitution. Overall, achievements were made in introducing such policies. However, due to the large share of standard agriculture and regional resources, and environmental diversity, such policies may have little effect in practice. The divergence between the policies and actual practices are explained, and important policies applicable to all developing countries are also recommended.

● Production, distributions and environmental risks of LM in Shaanxi were studied.

Shaanxi is a leading province in animal husbandry (AH) in China. However, the lack of provincial information on the characteristics and utilization potential of livestock manure (LM) hinders crucial management decisions. Therefore, we investigated the spatiotemporal distribution, availability and biogas potential of LM in Shaanxi, and examine the carbon emission reduction potential of AH. There has been a 1.26-fold increase in LM quantities in Shaanxi over the past 35 years, reaching 4635.6 × 10⁴ t by 2021. LM was mainly concentrated in northern Shaanxi and the eastern part of Hanzhong. Cattle and pig manure were the primary sources of LM, with the average LM land-load of 14.57 t·ha⁻¹ in 2021. While the overall AH in Shaanxi has not exceeded the environmental capacity, the actual scales of AH in Ankang and Hanzhong have already surpassed the respective environmental capacities, posing a higher risk of N and P pollutions. In 2021, the estimated biogas energy potential of LM was 1.2 × 10¹¹ MJ. From 2012 to 2021, the average carbon emission reduction potential in Shaanxi was 22%, with an average potential scale of 10%. The results of this research provide valuable data and policy recommendations for promoting the intensive use of LM and reducing carbon emissions in Shaanxi.

● Sugarcane and sugar beet yield and carbon footprint rose with time but profit declined

Climate change mitigation is a major challenge of human society. Currently, to this end, many countries including China are committed to achieving carbon neutrality within a few decades. China is a major sugarcane and sugar beet producing country and has one of the largest carbon footprint for sugarcane and sugar beet production globally. A comprehensive study was conducted on sugarcane and sugar beet crops grown in China for greenhouse gas (GHG) emissions mitigation potential, economic crop production from a sustainable sugar production perspective. Long-term trend analysis showed that yield and GHG emissions of sugarcane and sugar beet crops increased but the ratio of income to cost declined. Structural equation model analysis revealed nitrogen fertilizer and labor as the major drivers of GHG emissions for both sugarcane and sugar beet. For sugarcane and sugar beet, the path coefficient of N fertilizer were ‒0.964 and ‒0.835 and that of labor were 0.771 and 0.589, respectively. By transitioning the current cropping system to an improved model with optimized labor, N input and machinery use, the GHG emissions and total annual cost of sugarcane and sugar beet production can be reduced by 32% and 24%, respectively, by 2030, compared to a business-as-usual scenario. This is the first integrated and comparative study of environmental and economic sustainability of sugarcane and sugar beet production in China. These findings will enable all stakeholders of Chinese sugarcane and sugar beet industries to transform them into environmentally and economically sustainable sugar production.

● Methane led China’s growth in net greenhouse gas emissions over the pandemic.

To study the impact of the COVID-19 pandemic on agricultural carbon emissions in China, the greenhouse gas emissions generated by crop and livestock production, and agricultural material and energy inputs in China from 2019 to 2021 were systematically calculated. It was found that from 2019 to 2021, Net greenhouse gas emissions (NGHGE) from agriculture in China had an increasing trend. Methane emissions ranked first in NGHGE, with an annual proportion exceeding 65% and an increasing annual trend. CH₄ emissions were primarily influenced by enteric fermentation and rice production. Nitrous oxide emissions accounted for around 22% of annual NGHGE and decreased from 2019 to 2021. The main sources of N₂O emissions were the use of nitrogen fertilizers and manure management. Carbon dioxide emissions accounted for about 18% annually, with diesel and agricultural electricity use contributing to over 60% of CO₂ emissions. Soil carbon sequestration represented about a 6.1% lowering of NGHGE. The combined proportion of CH₄ emissions from enteric fermentation and rice production accounted for over 50% of total GHG emissions. The changes in NGHGE were mainly caused by disturbance of the livestock industry during the pandemic.

● Environmental impacts in the dairy sector are mostly related to emissions of ammonia and greenhouse gases.

This research aimed to quantify concentrations of ammonia (NH₃), carbon dioxide (CO₂) and methane (CH₄), estimate emissions, and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate zone. Gas distribution within the barn was observed to vary both vertically and horizontally, with the highest gas concentrations observed in the central area of the barn. NH₃, CH₄ and CO₂ ranged in 1.7–7.4, 7–18, 560–724 μg·g^–1, respectively. Natural ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions, influencing cow behavior and, consequently, gas production. Gas concentrations were the highest at air velocities below 0.5 m·s^–1. The highest concentration of NH₃ was observed when the temperature-humidity index (THI) was > 72 and ≤ 78; and CO₂ and CH₄ concentrations were the highest with THI ≥ 72 and decreased with THI ≤ 72. NH₃ concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings, and lower for CH₄ and CO₂. NH₃ and CH₄ emissions were the highest during barn cleaning, while the lowest NH₃ emissions occurred during activity of the cows (i.e., feeding, walking).

● It is crucial to comprehensively summarize remediation technologies and identify future development directions.

Metal(loid) pollution has emerged as a pressing environmental issue in agriculture, garnering extensive public attention. Metal(loid)s are potentially toxic substances that infiltrate the soil through diverse pathways, leading to food chain contamination via plant uptake and subsequent animal exposure. This poses a serious threat to environmental quality, food security, and human health. Hence, the remediation of metal(loid)-contaminated agricultural soil is an urgent concern demanding immediate attention. Presently, the majority of research papers concentrate on established, isolated remediation technologies, often overlooking comprehensive field management approaches. It is imperative to provide a comprehensive summary of remediation technologies and identify future development directions. This review aims to comprehensively summarize a range of soil remediation and enhancement technologies, incorporating insights from multiple disciplines including physics, chemistry, biology, and their interdisciplinary intersections. The review examines the mechanisms of action, suitable scenarios, advantages, disadvantages, and benefits associated with each remediation technology. Particularly relevant is the examination of metal(loid) sources, as well as the mechanisms behind both established and innovative, efficient remediation and enhancement technologies. Additionally, the future evolution of remediation technologies are considered with the aim of offering a scientific research foundation and inspiration to fellow researchers. This is intended to facilitate the advancement of remediation technologies and establish a robust foundation for sustainable development of soil.

● Research on heavy metal passivation and nitrogen emissions is necessary for the pig industry.

The widespread use of feed additives in intensive and large-scale pig farming has resulted in high levels of heavy metals in pig manure. The long-term application of organic fertilizers containing high levels of heavy metals leads to the accumulation of heavy metals in the soil, which not only causes heavy metal pollution in the soil, and also affect food safety and endanger human health. Composting is an economical and effective technical measures to achieve environmentally-sustainable treatment of pig manure and is a practical method to reduce the problem of heavy metals and to improve the resource value of pig manure. The composting process is accompanied by high temperatures and the production and emission of gases, and also lead to changes in the nitrogen content of the compost and provide opportunity for heavy metal passivation additives. This paper summarizes the forms and types of heavy metals present in pig manure and reviews the progress of research as well as the techniques and problems of in the composting process, and provides recommendations for research on heavy metal passivation and nitrogen retention in pig manure composting.

● First report of bacteria Paenarthrobacter nitroguajacolicus for effective control of cucumber corynespora leaf spot and promotion of cucumber growth.

Currently, the disease control in cucumber mainly depends on agrochemicals, which is not an environmentally benign strategy. Biocontrol bacteria not only resist plant pathogens but also promote plant growth, which is ecofriendly and sustainable option. A biocontrol bacterial strain BJ-5 was screened using Corynespora cassiicola as the target pathogen, and BJ-5 was determined to be Paenarthrobacter nitroguajacolicus by morphological and molecular methods. The effect of BJ-5 on C. cassiicola was studied, including the spore germination, cell membrane permeability and infected cucumbers. BJ-5 inhibited the germination of C. cassiicola spores in vitro and led to atrophy and deformation of the C. cassiicola budding tubes. BJ-5 caused the relative extracellular conductivity of C. cassiicola mycelia to increase compared with the control. Additionally, BJ-5 reduced the severity of cucumber corynespora leaf spot of cucumber infected with C. cassiicola. The inhibition efficacy of BJ-5 suspension as a foliar spray against cucumber corynespora leaf spot reached 63% inhibition, which is higher than a 5000-fold dilution of Luna-Son SC fungicide. In addition, BJ-5 was tested on the emergence of cucumber seedlings, recording the biomass and photosynthesis of cucumber during the growth period. BJ-5 at 1.5 × 10⁵ CFU·mL⁻¹ promoted the germination of cucumber seeds and increased biomass and photosynthesis at the adult plant stage. Also, the secondary metabolites of BJ-5 were determined. BJ-5 could produce chitinases, siderophore, cellulase, amylase and protease in the respective medium. Finally, adaptation assay of BJ-5 showed good salt tolerance and good adaptability in alkaline conditions, and that BJ-5 retains inhibition of fungi activity at higher temperatures. This is the first report of the biocontrol by P. nitroguajacolicus with antagonism to C. cassiicola and promote cucumber growth. This study indicates that P. nitroguajacolicus may serve as potential biocontrol agents against cucumber corynespora leaf spot fungus.

● Isolation of potential PGPR from rhizosphere sandy BRIS soil of Acacia mangium .

This study has isolated, characterized, and identified potential plant growth-promoting rhizobacteria (PGPR) with multiple PGP characteristics (N₂-fixation, P- and K-solubilization, IAA, and siderophores production) from the rhizosphere BRIS soil of Acacia mangium. A total of 24 pure colonies were isolated and only 8 colonies were selected for further evaluation of the growth rate in 5% organic molasses medium supplemented with 2% KNO₃. Based on the biochemical, potential PGP characteristics and growth performance, 3 superior PGPR strains were selected and identified as Paraburkholderia unamae (UA1), Bacillus amyloliquefaciens (UA6), and Enterobacter asburiae (UAA2) by partial sequencing of the 16S rRNA gene. The selected bacterial strains either in single or mixed (UA1 + UA6 + UAA2) cultures have shown a significant biochemical estimation of the PGP characteristics. Each strain has its own PGPR traits superiority with UA1 showing the best PGP characteristic followed by UA6 and UAA2. The use of mixed bacterial strains was beneficial as it showed the best performance in N₂-fixation, siderophores production, and significant effect on corn phenology, growth and yield compared to using a single strain. These types of microbes showed potential to be used as biofertilizer and should be exploited more.