Soil and water conservation and dryland farming performance: An emergy synthesis perspective on three typical farming systems in the Loess Plateau of China

The growing global population and rising food demand have intensified arable land scarcity, posing serious challenges to agricultural sustainability. Marginal lands, a vast underutilized reserve of potential cropland totaling approximately 2.7 billion hectares globally, are ecologically fragile and less productive, yet hold great potential for expanding both food and energy production. This study reviews the global distribution and key characteristics of marginal land, with a focus on current sustainable utilization models. Key challenges such as soil degradation, contamination, and economic constraints are discussed. These issues can be mitigated by adopting innovative approaches, including the conversion of agricultural waste, the application of molecular breeding techniques, the deployment of smart agriculture empowered by AI-driven cultivation practices, and the use of advanced land engineering. Achieving this objective requires collaborative efforts between governments, stakeholders, and farmers. This study provides a theoretical framework and technical support for the sustainable development and use of marginal land.

Soil salinity (ECe=8.55 dS m-1), a predominant abiotic stress factor, significantly impairs the growth, yield and pharmaceutical quality of the medicinal plant Silybum marianum (milk thistle). This study evaluated the potential of mango-residue biochar and foliar α-tocopherol (α-Toco) on the physiological stability, agronomic performance, and pharmaceutical quality of milk thistle under saline conditions. A two-season field trial was performed using a split-plot arrangement of biochar amendments (0-15 t ha⁻¹) and α-Toco applications (0-150 ppm). The integrated application of two treatments effectively mitigated salinity stress, leading to significant increases in growth and productivity. The optimal treatment (10 t ha⁻¹ of biochar and 150 ppm α-Toco) markedly enhanced both above- and below-ground biomass compared to the control. This synergistic effect was attributed to improved nutrient uptake (such as N, P, K⁺, Mg2⁺, Zn2⁺), and reduced Na+ accumulation. Furthermore, the highest treatment combination (15 t ha⁻¹ biochar × 150 ppm α-Toco), dramatically enhanced the antioxidant system by increasing endogenous α-tocopherol and ascorbate peroxidase activity. This treatment effectively alleviated oxidative damage, as evidenced by significant reductions in proline, H₂O₂ levels, and IC₅₀ values. Most importantly, these physiological improvements resulted in the highest seed yield (1.95 t ha⁻¹) and a significant increase in silymarin content (up to 3.172%). The synergy between biochar and α-Toco provides a sustainable strategy for enhancing milk thistle resilience and pharmaceutical quality in saline environments, offering a promising approach for the productive utilization of marginal lands under climate change conditions.

In this study, the perennial herbaceous C4 species Miscanthus × giganteus was planted using a randomized block design on a low-productivity, idle land located within the boundaries of Kahramanmaraş Sütçü İmam University. Three fertilizer levels 0, 60, and 120 kg ha⁻¹ were tested within the experimental blocks. Measurements of physiological traits were conducted during the vegetation period in 2015 and 2016. The gas-exchange parameters assessed included net assimilation rate, transpiration rate, stomatal conductance, water-use efficiency, and water potential. Growth-related parameters such as plant height, fresh and dry biomass, and total biomass content (extractive matter, holocellulose ratio, lignin ratio, and ash content) were analyzed. The biofuel production potential was evaluated by calculating the theoretical bioethanol yields and efficiencies from the biomass extracted from M. giganteus. The results of this study demonstrate that M. giganteus, grown under marginal land conditions, was not significantly affected by increasing fertilizer concentrations or adverse environmental conditions. Moreover, as a non-food energy crop, it successfully avoids the global “food vs. fuel” debate by being independent of the primary food sources relied upon by the world population.

Quinoa (Chenopodium quinoa Willd.) is an Andean grain crop introduced as a novel crop to many parts of the world in recent years. Recognized for nutritious seeds and high abiotic stress tolerance, it has been promoted as an element of climate-resilient agriculture, particularly in marginal environments. Successfully introducing new crops to sustainably increase and diversify agricultural production in such settings depends on environmental, economic and social factors of the agricultural context. This review critically assesses the potential and challenges of introducing quinoa as an alternative crop, focusing on marginal lands in Central Asia. We highlight quinoas broad genetic base to abiotic stresses such as drought, salinity and temperature extremes and discuss how it can be leveraged by breeding for marginal environments. Environmental effects, economic aspects and initial experiences with quinoa cultivation in Central Asia are discussed. Furthermore, we discuss broader socioeconomic implications, including land tenure and migration in marginal regions. We conclude that quinoa holds potential for improving sustainable agriculture in marginal environments, when integrated policies and long-term support enable its benefits for sustainable agricultural development. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Abstract The global expansion of photovoltaic systems for decarbonization increasingly occupies land resources and triggers ecological and agricultural trade-offs. Here we propose a marginal-land-based solution to ease these conflicts by integrating multi-criteria suitability constraints with a spatial non-dominated sorting algorithm to prioritize the use of suitable marginal land. We identify about 1.58 million square kilometers of marginal land suitable for photovoltaic development, including 0.40 million square kilometers ranked as top priority. Using only 0.3–0.9% of this suitable area could satisfy China’s projected photovoltaic installation demand for 2050. Depending on energy development pathways, following this solution could avoid the conversion of 1377–3765 square kilometers of cropland, 1549–4235 square kilometers of grassland, and 287–784 square kilometers of woodland. This would safeguard 429–1174 kilotons of annual grain production and prevent degradation of 1096–2998 square kilometers of forest-grassland ecosystems. These findings highlight the socio-ecological advantages and substantial energy potential of prioritizing marginal land for renewable energy expansion.

Melatonin as a protective signal in oats: enhancing salinity tolerance for sustainable agriculture on marginal lands.

Climate change-induced variability in temperature and precipitation increasingly constrains crop production on sandy-textured soils with low water-holding capacity and limited nutrient retention. Such soils, classified as Brunic Arenosols, are widespread across the temperate climate zone of Central Europe, particularly in post-glacial landscapes, where they constitute a significant proportion of marginal agricultural lands. This study evaluated the relative influence of growing-season weather conditions and selected soil physicochemical properties on the yield of Camelina sativa and Brassica carinata cultivated under low-input management on Brunic Arenosols in northwestern Poland during the 2023 season. Yields varied markedly among sites. Camelina sativa produced yields from 300 to 930 kg ha−1, with the highest yield recorded at the site characterized by higher BS and phosphorus availability. Brassica carinata produced yields from 0 to 370 kg ha−1, including complete yield loss at one location due to severe pathogen infestation. Spearman’s correlation analysis revealed that temperature was a key determinant for both crops (r = 0.77 for C. sativa; r = 0.82 for B. carinata). For Camelina sativa, yield was strongly associated with BS (r = 0.80) and available P (r = 0.69), whereas Brassica carinata was more sensitive to climatic variability, showing a negative relationship with precipitation (r = −0.63). The results indicate species-specific responses to soil fertility and weather conditions under water- and nutrient-limited conditions typical of Central European sandy soils. While Camelina sativa performance was more closely linked to soil chemical status, Brassica carinata appeared predominantly climate-driven. These findings highlight the broader relevance of the study for temperate regions of Central Europe and support the integration of soil fertility management with climate-adaptive strategies when introducing alternative oilseed crops to marginal lands.

Rapid urban expansion and land-use changes have increasingly encroached upon wetland ecosystems, leading to their degradation and loss, particularly in developing regions where planning control is limited. In cities like Port Harcourt, this has resulted in a transition from informal wetland settlements to more structured residential developments, raising critical concerns for sustainable urban planning and environmental management. This study examines the emergence and expansion of wetland neighbourhoods in Port Harcourt, focusing on their spatial patterns, socio-economic characteristics, underlying drivers, and implications for urban planning. Rapid urbanization, rising land values, and increasing housing costs within the formal urban core have intensified pressure on marginal lands, leading to settlement growth in environmentally sensitive wetland areas. A mixed-method approach was adopted, combining 131 structured questionnaires across six purposively selected neighbourhoods with field observations and geospatial analysis. Spatial techniques, including a distance matrix, were used to assess the relationship between settlement location and proximity to major road infrastructure. Findings reveal that wetland neighbourhoods are increasingly occupied by middle-income residents, indicating a transition from traditional low-income informal settlements to more hybrid development forms. Key drivers include housing affordability constraints, accessibility to transport corridors, availability of low-cost land, and weak development control mechanisms. Despite their accessibility, these neighbourhoods exhibit planning deficiencies such as irregular layouts, inadequate infrastructure, encroachment into drainage channels, and heightened flood vulnerability. The study concludes that wetland urbanization reflects structural housing and governance challenges and underscores the need for integrated, risk-sensitive planning approaches supported by geospatial technologies.

Slightly saline–alkali soils represent an important but underutilized land resource in northern China, and optimizing planting patterns is essential for improving sorghum productivity under such marginal conditions. This study aimed to evaluate the effects of wide–narrow row spacing combined with different planting densities on the canopy structure, photosynthetic performance, and grain yield of brewing sorghum. A field experiment was conducted from 2022 to 2024 at the Yulin Experimental Station in Shaanxi Province, China, using the brewing sorghum cultivar Liaonuo 16. Four planting treatments were established: wide–narrow row spacing (80/60 cm) with three planting densities (105,000, 112,500, and 120,000 plants ha−1) and uniform row spacing (60 cm) with 112,500 plants ha−1 as the control. Wide–narrow row spacing combined with higher planting density significantly improved canopy structure and light interception. The treatment with 120,000 plants ha−1 increased light interception in the middle and lower canopy layers during flowering and grain filling by 8.7% and 25.58%, respectively, and enhanced total canopy light interception by 3.33% and 1.96%. Moreover, the leaf area index and photosynthetic capacity were improved, resulting in a 10.1% increase in grain yield compared with the uniform row spacing treatment. Wide–narrow row spacing combined with a planting density of 120,000 plants ha−1 effectively optimizes canopy structure and enhances sorghum productivity in slightly saline–alkali soils, providing a practical cultivation strategy for improving resource use efficiency in marginal farmlands.

The development of bioenergy crops on saline–alkaline land has been recognized as a potential pathway for both land restoration and combating global warming. However, the role of soil organic carbon (SOC) dynamics under such conditions remains insufficiently quantified in long-term assessments. In this study, an exploratory assessment was conducted to evaluate the long-term soil carbon sequestration (SCS) potential and life-cycle greenhouse gas (GHG) emissions of sustainable aviation fuel (SAF) produced from Arundo donax in the Bohai Rim region of China. The CENTURY model was integrated with Long Short-Term Memory (LSTM) time series forecasting to simulate SOC dynamics under future climate scenarios (2024–2035). Compared with the original CENTURY simulation, the LSTM model yielded a substantially more conservative estimate of SOC accumulation, with an Ensemble Mean SCS rate of 0.032 t C/ha/a and a 95% confidence interval ranging from −0.079 to 0.143 t C/ha/a. This result indicates a positive regional average tendency toward soil carbon sequestration, while also suggesting that some locations may behave as carbon sources under less favorable climatic conditions. The total SCS potential across the study area was estimated at 0.615 Tg C. When these soil carbon benefits were incorporated into the life-cycle assessment of Fischer–Tropsch (F-T) SAF, the pathway could become potentially net-negative under the adopted assumptions, reaching −32.1 g CO2e/MJ, which corresponds to a potential reduction of 136.1% relative to fossil aviation fuel. These results should be interpreted as exploratory and scenario-based, given that large-scale cultivation of Arundo donax has not yet been established in the Bohai Rim region and the assessment therefore relies on assumptions. Beyond GHG mitigation, the cultivation of Arundo donax on degraded saline–alkaline soils may also have potential relevance to broader sustainability objectives, including SDG 13 (Climate Action) and SDG 15 (Life on Land). These findings highlight the possible synergies among energy crop cultivation, soil restoration, and climate neutrality goals, and provide preliminary insights for integrating marginal land utilization into sustainable land management and low-carbon aviation strategies.

Lemongrass: climate-smart crop for marginal lands.

Voluntary conservation programs are increasingly used to align rural development with ecosystem protection within working landscapes, yet their effectiveness depends on the willingness and capacity of landowners to participate. To explore factors that influence participation, we investigated socioenvironmental characteristics of rural properties in a conservation program in the Brazilian Atlantic Forest. Using Bayesian modeling across 18 717 properties, we found participants concentrated in marginal agricultural lands and in properties with large extents of riparian areas, suggesting a pattern of self-selection into program participation. Using participation probabilities, we identified ~ 5000 additional properties to join future conservation programs, in the same area. These findings suggest that incentive-based policies may reward voluntary conservation while successfully engaging landowners in marginal lands. Voluntary conservation schemes tend to attract landowners predisposed to conservation, while struggling to engage those facing higher opportunity costs. Achieving transformative outcomes will require incentive structures that better align economic competitiveness with ecological priorities.

Carbon mitigation potential of deploying energy crops on marginal lands in China under climate change scenarios.

Assessment of bioenergy crop productivity and carbon emissions mitigation potential on marginal lands in China based on the machine learning model and meta-analysis

Abstract marginal land, despite limitations such as low soil fertility and restricted water access, holds potential for productive use. Cultivating medicinal plants, such as long pepper, offers a viable strategy to increase farmer income while conserving biodiversity. This study analyzes how economic factors, government involvement, and environmental conditions affect farmers’ motivation to sustain long pepper farming in Sumenep Regency, the largest producer in Madura. Researchers collected primary data from one hundred farmers through structured questionnaires and analyzed the data using multiple linear regression with the Partial Least Squares approach. The findings show that economic conditions, government support, and environmental suitability significantly and positively influence farmers’ motivation. Stable income, technical assistance, and favorable natural conditions act as key drivers of sustainable farming. However, challenges such as limited access to credit and water scarcity hinder progress and demand strategic interventions. This research also offers recommendation as concrete action by integrating the three aspects (economic, environmental, and government) forming farmer group only for the long pepper farmers to continue to be improved.

Saline-alkali stress is a major abiotic constraint limiting cereal productivity on global marginal lands. This study integrated multiomics and physiological phenotyping analyses to characterize leaf position-specific stress responses in contrasting oat cultivars. Leaf excision experiments confirmed upper third leaf (L3) retention is the critical determinant of oat survival under stress: L3-excised plants all died within 13 days post-treatment, while first leaf (L1)-excised plants maintained survival rates comparable to intact controls. All tested oats showed consistent position-dependent resilience patterns: although tolerant lines have higher overall tolerance, all cultivars exhibit far milder functional impairment in L3 than L1, with multiomics data confirming position-specific regulation of photosynthesis, AsA-GSH and TCA cycle pathways underpins this difference. These findings reveal a novel tissue-specific tolerance regulatory mechanism, guiding saline-alkali tolerant crop breeding.

Saline–alkaline water constitutes a vital strategic non-traditional fishery resource in China, characterized by high pH values, elevated carbonate alkalinity, and complex ionic compositions. These extreme environmental conditions impose significant stress on aquatic animals, mainly by inducing ionic toxicity and disrupting acid–base regulatory mechanisms. Such disruptions subsequently lead to osmotic imbalance, metabolic dysregulation, and immunosuppression, thus restricting the survival and growth of aquatic species in aquaculture systems. Consequently, the sustainable development of the saline–alkaline aquaculture is imperative for enhancing production efficiency and promoting the utilization of marginal land and water resources. This review comprehensively summarizes the current status of saline–alkaline aquaculture and highlights the stress-inducing impacts of salinity, alkalinity, and specific ionic ratios on teleost fishes and crustaceans. It further explores key adaptive mechanisms, including osmoregulatory and ionoregulatory strategies, bioenergetic trade-offs related to oxygen consumption and ammonia excretion, coordinated antioxidant and innate immune responses, as well as recent findings from multi-omics research. This review aims to offer a scientific foundation for the selection and breeding of saline–alkaline-tolerant strains, the precise regulation of aquaculture water environments, and the development of ecological aquaculture models in saline–alkaline regions, thereby facilitating the sustainable utilization of saline–alkaline land and water resources.

Abstract The terrestrial carbon sink is a critical buffer in the climate system, yet its persistence under rising atmospheric CO 2 remains a major uncertainty in Earth system projections. Using an ensemble of 20 dynamic global vegetation models from the TRENDY v12 project, we decompose the CO 2 sensitivity of the land carbon sink, represented by net biome production (NBP), to diagnose long-term changes in intrinsic efficiency. We identify a robust, emergent turning point in the simulated intrinsic CO 2 sensitivity of NBP, shifting from a significant multi-decadal increase to a sustained decline around 1980. This reversal is reproduced in both carbon-only and coupled carbon–nitrogen model classes and is consistent with a progressive decoupling between CO 2 sensitivities of carbon inputs and losses (net primary production, NPP versus heterotrophic respiration, Rh). In contrast, the turning point is not readily detectable in the total apparent sensitivity, reflecting both the dominance of high-frequency climate and land-use variability and interacting environmental effects that may partially offset intrinsic CO 2 responses. Together, these results point to a weakening intrinsic efficiency of the terrestrial carbon sink, implying diminishing marginal land uptake per unit CO 2 increase and a potentially more constrained resilience of future land carbon sequestration than suggested by raw sink magnitudes alone.

Xanthoceras sorbifolium (Yellowhorn) is an underutilized, multipurpose, climate-resilient oilseed with emerging food and industrial potential. This review consolidates current knowledge on its botany, agronomy, kernel composition, extraction technologies, protein and bioactive functionality, food uses, regulatory considerations, and sustainability challenges. Yellowhorn offers high-quality oil with ≈94% unsaturated fatty acids (notably 3.5–4% nervonic acid), while defatted kernel meal contains 31–37% protein (w/w). The matrix also carries bioactives such as tocopherols in the oil (70–530 mg/kg), phytosterols (1420–2970 mg/kg), and saponins (up to 11.62%), alongside flavonoid extracts that show promising antioxidant activity (DPPH EC50 ≈ 10.7 µg/mL). Extraction methods, including cold pressing, solvent systems, and supercritical CO2, present trade-offs in yield (≈87.8%, ≈60.4–98.04%, and ≈56.5–89.63% respectively), bioactive retention, and scalability, while co-product valorization can improve economic and environmental performance. Regulatory acceptance in the U.S. will likely depend on a refined-oil, specification-driven Generally Recognized as Safe (GRAS) pathway supported by compositional and toxicological evidence. Sustainability priorities include breeding improvements and supply-chain development on marginal lands, valorization of co-products, and integration of life cycle assessment (LCA), both of which are currently under-reported for Yellowhorn. Future directions emphasize process optimization for simultaneous oil-protein recovery, selective purification of functional lipids, encapsulation for stability, and human studies to substantiate claims. Collectively, Yellowhorn represents a promising climate-ready ingredient system requiring targeted research to enable safe, scalable, and sustainable adoption.