● A precision symmetric finger-clamping garlic seed-metering device was designed.

This study aimed to address the sowing quality problems commonly encountered in the mechanized process of sowing garlic seeds, such as a low single-seed rate. To rectify these types of issues, the symmetric seed-collection spoons and the seed-distribution plate structures were designed based on an existing finger clip plate garlic seed-metering device. First, the optimal installation angle of the seed-distribution plate and optimal number of seed-collection spoons were determined using single-factor simulation tests based on discrete element method-multibody dynamics (DEM-MBD) coupling, and the effects of different seed-collection spoon tapers, finger clip gradual closing angles, and seed tray rotation speeds on the performance of the seed-metering device were analyzed. Second, based on the single-factor simulation tests, a quadratic regression orthogonal rotary combination simulation test was conducted using the taper of the seed-collection spoon, finger clip gradual closing angle, and seed tray rotation speed as the test factors and the single-seed rate (1 seed per spoon), empty rate (0 seed per spoon), and multiple-seed rate (≥ 2 seeds per spoon) as the test indices. Parameter optimization was performed using an established regression model. Finally, bench tests were conducted to verify the reliability of the simulation results. The results showed that the optimal parameter combinations were a seed-collection spoon taper of 1.6, a finger clip gradual closing angle of 21.4°, and a seed tray rotation speed of 31.5 r·min⁻¹. Also, the seed-metering device exhibited a single-seed rate of 94.2%, an empty rate of 2.1%, and a multiple-seed rate of 3.7%.

● 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.

● 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.

● Saline-alkali land is an important underutilized resource in China that could complement arable land and maintain the food security.

Soil salinity is a global threat to the productivity of arable land. With the impact of population growth and development of social economy in China, the area of arable land has been shrinking in recent decades and is approaching a critical threshold of 120 Mha, the minimum area for maintaining the national food security. Saline-alkaline land, as important backup reserve, has been receiving increased attention as an opportunity to expand land resources. This review first summarizes the general principles and technologies of saline soil reclamation to support plant growth, including leaching salts or blocking the rise of salts, and soil fertility enhancement to improve the buffering capacity. Then the progress in this area in China is described including the customization of technologies and practices used in different saline-alkali regions. Following the soil management strategies, the concept of selecting crops for saline soil is proposed. This encompasses halophyte planting, salt-tolerant crop breeding and the application of saline-adapted functional microorganisms to improve the adaptation of crops. Finally, the current problems and challenges are evaluate, and future research directions and prospects proposed for managing this major soil constraint.

● Addresses global challenges like food insecurity, climate change and social inequality.

The escalating recognition of sustainable agriculture and food systems is a response to the multifaceted challenges of food insecurity, climate change, environmental deterioration and economic pressures. In this review, sustainable agriculture is characterized as an array of farming practices that effectively address immediate demands, while simultaneously safeguarding the potential of future generations to fulfill their needs. The primary objectives include sustained productivity, pollution reduction, and economic viability and sustainability. Sustainable food systems incorporate dimensions beyond production, including processing, distribution, consumption patterns, and waste management along the entire food supply chain. An abundance of research underscores the manifold benefits offered by sustainable agriculture and food systems to society at large. These advantages include fostering climate resilience, curbing greenhouse gas emissions, enhancing water quality, promoting biodiversity, enriching soil fertility, fortifying rural livelihoods and nurturing community well-being. Nevertheless, the path toward sustainability is strewn with significant challenges. These include substantial costs involved in transitioning, conflicts in policy objectives, and the pervasive influence of traditional methods. Achieving sustainability requires the execution of holistic strategies that traverse various sectors and scales. Accelerating this progress can be facilitated through the adoption of diverse strategies, including agroforestry, agroecology, urban agriculture, farmer knowledge exchange, ecosystem service payments and supply chain shortening. However, the success of these strategies hinges on the provision of appropriate policies and incentives. Further research is vital to ascertain the ideal conditions for implementing specific interventions and to assess the comprehensive expenses and benefits linked to them. This review emphasizes the assertion that widespread adoption of sustainable practices in agriculture and interconnected food systems has positive impacts in terms of community nutrition, conservation of natural resources and long-term economic progress.

● Continuous cropping obstacles (CCOs) cause, on average, 22% reduction in crop production, seriously threatening sustainable agricultural development.

Due to the increasing global population and limited land resources, continuous cropping has become common. However, after a few years of continuous cropping, obstacles often arise that cause soil degeneration, decreased crop yield and quality, and increased disease incidence, resulting in significant economic losses. It is essential to understand the causes and mitigation mechanisms of continuous cropping obstacles (CCOs) and then develop appropriate methods to overcome them. This review systematically summarizes the causes and mitigation measures of soil degradation in continuous cropping through a meta-analysis. It was concluded that not all continuous cropping systems are prone to CCOs. Therefore, it is necessary to grasp the principles governing the occurrence of diseases caused by soilborne pathogens in different cropping systems, consider plant–soil-organisms interactions as a system, scientifically regulate the physical and chemical properties of soils from a systems perspective, and then regulate the structure of microbial food webs in the soil to achieve a reduction in diseases caused by soilborne pathogens and increase crop yield ultimately. This review provides reference data and guidance for addressing this fundamental problem.

● Chicken manure and composted kitchen waste had similar mineralization but different humification.

Organic inputs are key to increasing soil organic carbon in agricultural soils. This study aimed to unravel the process of mineralization and humification of chicken manure (CM) and composted kitchen waste (KW) using an in situ litter-bag incubation experiment. The results indicated that over 50%, 64% to 72%, and 62% to 85% of the initial mass, carbon and nitrogen, respectively, were lost through incubation with a marked loss occurring during the first 28 days. Increased humic acids (HAs), humus (HS) and degree of humification, along with a decrease in the level of fulvic acids and precursors for humic substances were observed through incubation. By comparison, CM demonstrated higher carbon and nitrogen conservation efficiencies and greater humification compared to KW. Additionally, a higher degree of humifaction and larger quantities of HAs and HS were not favorable for carbon and nitrogen conservation. Further structural equation modeling indicated that microbial community had a strong effect on carbon loss and nitrogen release, while stoichiometric properties of organic inputs were the main determinant of the mineralization and humification processes. These findings will enhance understanding of litter decomposition in soils and provide valuable references for soil carbon sequestration with organic inputs.

● 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).