Forests dominated by Fagaceae species constitute the largest proportion of China’s total forest area and forest volume, playing a crucial role in carbon sequestration and climate mitigation. However, the variation in gross primary productivity (GPP) across different climate zones and taxonomic genera, as well as its driving factors, remains poorly understood. In this study, we employed variance decomposition, partial least squares structural equation modeling, and piecewise linear regression to identify the drivers of GPP derived by SIF in Fagaceae-dominated forests in China. The results indicated that the GPP varied significantly across taxonomic genera and climate zones. Specifically, the forests dominated by Castanopsis and those located in the south subtropical zone exhibited the highest GPP (6553.5 g C m−2 yr.−1), whereas the Quercus-dominated forests and those in the north temperate zone showed the lowest GPP (1300.9 g C m−2 yr.−1). The observed variation in GPP was primarily attributed to climate features (e.g., MAT, MTWM, PAR) (56.83–81.29%) and forest characteristics (8.06–23.58%), with minimal contributions from soil and topographic factors. The structural equation models further demonstrated that forest characteristics and climate factors directly influenced GPP, while topography and soil factors had indirect effects on GPP through cascading pathways. Additionally, the critical threshold of forest age on GPP varied depending on genus and climate zone, peaking at 90.40 years in the middle temperate zone and 91.00 years in Quercus-dominated forests. The findings improve our understanding of spatial patterns and drivers of GPP in Chinese Fagaceae-dominated forests, and the identification of critical forest age thresholds clarifies productivity shifts across development stages, thereby contributing to a better assessment of national forest carbon sequestration potential.

Fertigating with phosphorus (P) through drip irrigation has recently emerged as a promising strategy to enhance phosphorus use efficiency (PUE) in potato production. However, due to P’s limited mobility in soil—particularly in the lateral direction—and the relatively sparse root system of potatoes, its uptake remains suboptimal under conventional practices. This study, conducted from 2021 to 2022 in Inner Mongolia, China, investigated whether modifying drip tape depth and emitter spacing could improve the spatial alignment between soil-applied P and potato roots, thereby boosting PUE. Two variables were tested: the depth of drip tape placement and the distance between emitters. Key parameters measured included plant dry weight, leaf area index (LAI), soil Olsen P concentration, root distribution, tuber yield, and partial factor productivity of fertilizer P (PFPP). Results showed that subsurface drip tape placement at a 10 cm depth or reducing emitter spacing to 15 cm significantly improved root-P alignment. These adjustments led to increased P uptake, higher LAI, greater biomass accumulation, and improved tuber yield and PFPP compared to the conventional setup (surface drip tape with 30-cm emitter spacing). The findings underscore the importance of optimizing drip tape configuration to synchronize P availability with crop demand. Deep placement and closer emitter spacing can significantly enhance PUE and yield in drip-fertigated potato systems, offering valuable guidance for more efficient P management in potato production.

Over 1.8 billion people worldwide face water scarcity threats, with the challenge particularly acute in densely populated and agriculture-intensive drylands. Northern China, among the world’s most water-stressed regions, faces an intensifying yet poorly understood imbalance between freshwater supply and consumptive demand. Here, we reveal a sustained decline in terrestrial water storage (TWS) in recent decades (2004–2022) at −9.15 ± 1.24 Gt/yr. Although climate change delivers substantial water gains (+12.44 Gt/yr), irrigation consumption (−16.16 Gt/yr) overwhelms these climate-driven water gains and dominates regional water depletion. Industrial and domestic water use contribute an additional −4.43 Gt/yr, while large-scale ecological restoration inadvertently amplifies water losses through vegetation-driven enhancement of evapotranspiration (−0.91 Gt/yr). Future projections indicate that under the intermediate and high emission scenarios, TWS will continue declining through mid-century (2041–2060), with supply-demand gaps widening by 65% and 120%, respectively. These findings reveal an anthropogenic water management crisis and highlight the urgency of systemic interventions to avoid escalating water risks. Terrestrial water storage declined in Northern China during 2004–2022 due to anthropic consumption despite climate-driven gains, and is projected to continue declining, according to satellite observations, Bayesian data fusion, machine learning, and a physically constrained attribution framework.

Late blight (Phytophthora infestans) severely reduces potato production in semiarid Inner Mongolia, and intensive chemical control presents ecological risks. In this study, an ecological strategy for sustainable potato production was developed using a potato-common vetch intercropping system with reduced irrigation and phosphorus redistribution. Phosphorus redistribution could promote common vetch biological nitrogen fixation and growth, thereby strengthen its ecological service capacity. A two-year field experiment demonstrated that intercropping improved tuber yield (by 3.57-22.96%) and comprehensive quality (by 77.80%-307.57%), and reduced late blight (by 23.84%-42.60%). Intercropping under reduced irrigation and phosphorus redistribution yielded comparably to that under conventional irrigation with phosphorus redistribution, reducing the disease index by 42.3% relative to monoculture. Potato yield was positively associated with soil water content and available phosphorus. Quality was correlated with soil total carbon, total potassium, and available phosphorus, and the disease index exhibited a negative correlation with soil available phosphorus and nitrate nitrogen. Intercropping enriched 15 disease-suppressive taxa and shifted fungal community assembly from deterministic to stochastic processes, with fungi contributed most to disease suppression (11.3%). Fifteen disease-suppressive metabolites were also enhanced under intercropping, particularly when phosphorus was redistributed. Agar plate inhibition assays confirmed the inhibitory effects of 2-furancarboxaldehyde, imidazole-4-acetaldehyde, and methyl jasmonate on pathogen growth. Variance partitioning analysis identified disease-resistant metabolites as the key driver (17.2%). Common vetch growth coordinated soil nutrients, disease-resistant microbiota, and metabolites to suppress late blight. Phosphorus redistribution improved yield and quality while reducing disease under reduced irrigation, supporting potato production with lower water and chemical inputs.

In recent decades, escalating climate change, continuous population growth, rapid urbanization, and extensive agricultural development have placed increasing pressure on global ecosystems. Particularly in China, intensive agricultural practices and excessive water resource consumption have led to severe ecological challenges, threatening the health coupling of the food-water-ecosystem (FWE) function nexus. It is therefore critical to assess the impacts of multiple environmental changes on the FWE coupled system. Here, we employed an assessment process, ’indicator selection - element quantification - trade-off/synergistic effects - driving forces’, to elucidate the intricate dynamics of the FWE nexus from the perspectives of climate change, socioeconomic development and ecological restoration in a typical ecologically fragile region (the agro-pastoral ecotone of northern China, APENC). The results indicate that between 2000 and 2020, crop production in APENC increased from 45.8 Mg/km2 to 140.7 Mg/km2, while water yield remained low but showed fluctuating growth. The expansion of forest land contributed to the regional soil carbon sequestration, with carbon storage (CS) increased by 10.0%. Soil conservation (SC) and habitat quality (HQ) also increased by 76.8% and 1.6%, respectively, contributing to the mitigation of soil erosion and habitat loss. Over time, trade-offs within the FWE nexus weakened, while synergistic effects grew stronger. Climate conditions were most strongly associated with the FWE nexus, with precipitation contributing approximately 29.4%–34.3%, while ecological restoration has partially mitigated cropland expansion in APENC, thereby improving the ecological environment. However, the negative pressures brought about by rapid socio-economic development should not be overlooked.

The root-to-shoot ratio (R/S) is a key parameter for estimating forest carbon stocks and modeling carbon cycles at global and regional scales. We compiled a large dataset (n = 7,980) from Chinese forest ecosystems and employed the Random Forest algorithm, combined with shapley additive explanations (SHAP) and piecewise structural equation modeling, to identify the key drivers of R/S and their threshold effects. Consistent with optimal partitioning theory, R/S variation is driven by both biotic and abiotic resource limitations. Our results showed that the average R/S in natural forests (NF) (0.262 +/- 0.001) was significantly higher than that in planted forests (PF) (0.228 +/- 0.002), and deciduous forests exhibited higher R/S values than evergreen forests. Mean annual temperature (MAT) and stand age (Age) were the main drivers of R/S variation in NF and PF, respectively. The MAT threshold for R/S in NF was higher in broadleaved than in coniferous forests. In PF, R/S generally decreased with Age, with the transition zones from positive to negative responses occurring earlier in broadleaved forests (14.01-16.22 years) than in coniferous forests (17.31-19.08 years). Climate, soil, and stand factors exerted direct negative effects on R/S, whereas topography mainly influenced R/S indirectly through its effects on climate. The predicted R/S values ranged from 0.161 to 0.487, and the coefficient of variation attributable to forest type and forest origin was predominantly below 15%. These findings highlight the importance of forest origin and forest type in R/S estimation and provide a reliable reference for carbon accounting in China.

Forest structural attributes such as density, size, and age are important determinants of productivity; however, whether and how this relationship changes across a wide geographic range with varying climate and soil conditions requires validation. Quercus mongolica-dominated forests are widespread in Northern China; however, the spatial characteristics and mechanisms underlying their productivity remain poorly understood. We integrated tree-ring data with field plots from 17 sites and 47 plots spanning approximately 15.5 degrees latitude and 25.0 degrees longitude to evaluate the relative importance of climatic, edaphic, and forest structural factors (forest density, age, and tree size) on the forest productivity. Allometric equations were used to convert diameter growth into estimates of aboveground and belowground net primary productivity (ANPP and BNPP, respectively). Fixedeffect regression and structural equation modeling were used to assess the effects of forest structure and environmental variables on ANPP and BNPP. The sampled forest density ranged from 375 to 1700 trees ha-1, age varied from 10 to 197 years, and diameter at breast height (DBH) ranged from 5.0 to 63.3 cm. ANPP ranged from 2.1 to 7.4 t ha-1 yr-1, whereas BNPP ranged from 0.2 to 2.4 t ha-1 yr-1. Forest density and maximum DBH emerged as the strongest positive predictors of ANPP and BNPP, whereas age was a significant negative predictor. The structural equation model showed that climatic and soil variables only indirectly affected BNPP through their effects on forest structure. This study highlights the need to consider forest age, in addition to density and tree size, to estimate primary productivity across a wide geographic range.

The growing global demand for grain drives a greater need for nitrogen (N) input. Yet, it contributes to nitrous oxide (N2O) emissions, aggravating global climate change. To tackle this dual challenge of fulfilling crop demands while maintaining or reducing N2O emissions, a field study was performed in wheat-green manure cropping system to assess the effects of varying fertilizer application (N100, N90 and N80: N fertilizer reduced by 0%, 10% and 20%) combined with green manure return strategy (GMR: green manure roots return, GMRS: green manure roots and shoots return), and wheat fallow after harvest (CK) on wheat yield and yield stability from 2020 to 2024, N2O emissions, as well as N2O emission intensity from 2022 to 2024. Results showed that, although N fertilizer combined with green manure return strategy increased spring wheat yield by 8%–22% by increasing soil mineral N contents, it decreased yield stability compared with CK. Soil N2O emissions were mainly negatively and positively regulated by pH and NO3−-N content in saline-alkali soil, respectively. N80 decreased cumulative soil N2O emission and N2O intensity by 20% and 10% compared with N100, respectively. Irrespective of the variations in N fertilizer levels, GMR decreased cumulative N2O emission and N2O intensity by 20%–34% and 22%–38% compared with GMRS, respectively. Overall, the findings highlighted N fertilizer reduced by 20% (160 kg N ha −1) with green manure roots returned in relative to normal rate (200 kg N ha −1) is a viable option to ensure spring wheat yield and alleviate soil N2O emission in saline-alkali agroecosystem.

Green manure strongly affects saline-alkali soil organic carbon (SOC) sequestration. The mechanism by which green manure influences the contribution of plant and microbial-derived carbon (C) to SOC in wheat-green manure cropping system remains unclear. Herein, plant residue C (PRC), microbial, bacterial, and fungal necromass C (MNC, BNC, and FNC), enzyme activity and microbial community were determined under wheat fallow after harvest (CK), green manure roots return (GMR), and green manure shoots and roots return (GMRS) in a fiveyear field experiment. Compared with CK, GMR and GMRS increased SOC content by 12 % and 11 % at 0-20 cm, respectively. Specifically, GMR accelerated the lignin biotransformation by increasing the relative abundance of K-strategy fungi, caused a reduction in the contribution of plant residues to SOC by 16-31 %. While GMR increased MNC, especially BNC by 1.6-2.8 times, which was the primary driver of SOC sequestration. Comparatively, GMRS increased the relative abundance of r-strategy bacteria by 12-13 %, and C- and Nacquisition enzymes by 12-17 % and 56-68 % compare to CK. This in turn, increased the accumulation of PRC, but decreased MNC (especially FNC) contribution to SOC. Overall, green manure return strategies altered the contribution of plant residues and microbial necromass to SOC by regulating microbial life strategies. MNC (especially FNC) contributed more to SOC than PRC. Therefore, green manure specially root return is a viable option to drive SOC accumulation via microbial necromass formation in wheat-green manure cropping system in saline-alkali soils.

Study of niche characteristics, species interactions and community connectivity along elevation gradients contributes to our understandings on species' spatial interactions and vicarious distribution pattern, and helps reveal congeneric species coexistence and formation mechanisms of species distribution boundaries. In this study, we conducted a field survey on five types of Quercus communities across six elevation belts ranging from 900 to 2300 m (a.s.l) on the north and south slopes of Qinling Mountains, where the north subtropical and warm temperate zones divide. We analyzed the importance values, niche widths, niche overlaps, competition, interspecific associations of the three dominant Quercus species, as well as community connectivity. The richness of tree layer in the vicarious distribution of Quercus communities was relatively low, with Pinus (Pinus armandii and Pinus tabuliformis) being the main associate species. The chi 2 test and Spearman analysis demonstrated a significant negative correlation between Pinus and Quercus. The nich widths of all three studied Quercus species were found to be wider in their core communities compared to their edge communities, pariticularly on the south slopes. The niche overlap of dominant species on the both slopes were at a relatively low level, while higher niche overlap observed on the north slopes compared to the south slopes. The elevation trend in niche overlap among dominant species was consistent with interspecific competition intensity. Compared to the core and upper edge areas, the Quercus communities in the lower edge area exhibited greater niche overlap and a higher proportion of interspecific competition. The resutlts of variance ratio (VR) and W statistic values indicated that the Quercus communities on the both slopes primarily exhibited a non-significant negative correlation. The associations among dominant species were weak, resulting in a relatively loose community structure. Overall, the communities were in a relatively stable stage of middle-late succession. For the conservation and restoration process of Quercus forests, appropriate artificial interventions should be implemented to adjust interspecific relationships and enhance the strength of interspecific connections.

Climate change is anticipated to escalate the frequency and severity of global natural disasters over the next few decades, thereby significantly reshaping species distributions and populations. Species distribution models (SDMs), as essential tools in biogeography and biodiversity conservation, are pivotal for evaluating the impacts of climate change on species and forecasting their distribution ranges under different climate change scenarios over various periods. However, the absence of necessary background knowledge for model construction significantly affects the accuracy of these models, with the selection of different occurrence data sources being a key factor that constrains the accuracy of model predictions. In this study, using Quercus variabilis as a case study, which has diverse ecological, economic, and cultural values, we employed the Biomod2 ensemble modeling platform to comparatively analyze disparities between two different occurrence data sources (i.e., online specimen and scientific survey data) in the species distribution prediction accuracy, relative contribution of major environmental variables, and predicted distribution ranges. Furthermore, we examined potential discrepancies between these two data sources in the migration distance and direction of the species distribution centroid under different future climate scenarios over various periods. Our results indicated substantial differences in the simulation outcomes of SDMs derived from various occurrence data sources. SDMs based on scientific survey data had higher predictive accuracy (AUC = 0.9720, TSS = 0.8370), with the simulated species distribution ranges not only closely matching the actual distributions but also showing more pronounced changes in suitable habitat areas and centroid migration trends under future climate scenarios. In comparison, models based on online specimen data predicted a wider species distribution range, yet exhibited less pronounced trends in suitable area changes and centroid migration under future climate scenarios. Additionally, although the main environmental variables affecting the simulation outcomes from different occurrence data sources were essentially identical, they varied in their contributions and order of importance. Among them, human activity had a relatively stronger contribution for the online specimen data (17.76%), while topographic variables had a stronger impact for the scientific survey data, such as elevation (17.79%). Therefore, the choice of occurrence data sources have a significant impact on SDMs modeling results; this study provides insights and guidance for selecting optimal occurrence data sources to enhance the reliability of SDMs simulations.

In a nine-year field experiment in a wheat–maize–sunflower cropping system in Hetao Irrigation Area, Inner Mongolia, China, organic amendments applied as straw, manure, green manure, and the combination of green manure and straw increased wheat and maize yield, soil aggregate stability, and soil microbial activity in comparison with chemical fertilizer, without changing greenhouse gas emission intensity.

The characteristics and responses of soil bacterial communities and potato productivity to different fertilization treatments in farmlands in the agropastoral zone of Inner Mongolia were investigated. Moreover, the diversity and structure of soil bacterial communities and potato productivity under different fertilization treatments (no fertilization, CK; phosphorus-deficient treatment, NK; conventional fertilization, NPK; and organic–inorganic combination, NPKM) were assessed using Illumina high-throughput sequencing. The results revealed that soil pH, organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) content, and potato productivity were significantly increased under fertilizer treatments (NK, NPK, and NPKM) compared with those under CK, with NPKM treatment having the best enhancement effect. The application of organic fertilizers significantly increased the Shannon, evenness, Chao1, and Ace indices of soil bacterial communities and reshaped the bacterial community structure. Random forest model analysis revealed that soil pH and TP significantly affected soil bacterial diversity, whereas soil pH, SOM, TP, and TN significantly affected soil bacterial community structure. Correlation and structural equation modeling analyses revealed that soil TP and SOM indirectly affected potato productivity by changing soil bacterial diversity and community composition. The results of this study provide a scientific basis for improving the quality and productivity of farmland soil to guide the rational fertilization of farmlands in the agropastoral zone of northern China.

The incorporation of green manure into cropping systems is a potential strategy for sequestering soil carbon (C), especially in saline-alkali soil. Yet, there are still unknown about the substitution impacts of green manure on nitrogen (N) fertilizer in wheat-green manure multiple cropping system. Herein, a five-year field experiment was performed to determine the impact of three levels of N fertilizer inputs [i.e., N fertilizer reduced by 0 % (100N), 10 % (90 N), and 20 % (80 N)] with aboveground biomass of green manure removal (0GM) and return (100GM) on soil organic carbon (SOC) storage and its primary determinants. The results demonstrated that no significant interaction on SOC storage was detected between green manure and N fertilizer management. 80 N enhanced SOC storage in bulk soil by 7.4 and 13.2 % in 0 - 20 cm soil depth relative to 100 N and 90 N ( p < 0.05). Regardless of N fertilizer levels, compared with 100GM, 0GM increased SOC storage in bulk soil by 14.2 - 34.6 % in 0 - 40 cm soil depth ( p < 0.05). This was explained by an increase in soil macro -aggregates ( >2 and 0.25 - 2 mm) proportion contributing to SOC physical protection. Meanwhile, the improvement of SOC storage under 0GM was due to the decrease of soil C- and N -acquisition enzyme activities, and microbial resource limitation. Alternatively, the variation partitioning analyses (VPA) results further suggested that C- and N -acquisition enzyme activities, as well as microbial resource limitation were the most important factors for SOC storage. The findings highlighted those biological factors played a dominant role in SOC accumulation compared to physical factors. The aboveground biomass of green manure removal with N fertilizer reduced by 20 % is a viable option to enhance SOC storage in a wheat -green manure multiple cropping system.

Context: Inner Mongolia is a major potato-producing region in China. Soil quality degradation and water deficiency limit the local potato industry. Legumes can improve soil fertility and moisture, an intercropping system of common vetch with reduced irrigation was established to achieve potato production and soil restoration considering the annual cultivation system in Inner Mongolia. Methods: A two-factor field experiment design was then used. The first factor was the plant pattern with two levels, namely, potato monoculture (M) and potato-common vetch intercropping (I). The second factor was the irrigation amount with two levels, namely, reduced irrigation (R) and conventional irrigation (C). qPCR and high-throughput sequencing were used to determine soil microbial abundances and communities. Results: After two years of field experiments, reduced irrigation significantly (p < 0.05) reduced the aboveground biomass of common vetch by 36.06%. Reduced irrigation reduced potato quality by 11.87-31.37%, but intercropping compensated for this shortcoming. Compared with potato monoculture, common vetch incorporation into the soil significantly (p < 0.05) increased the soil water content and available nutrients, by 10.98% and 13.75-55.08%, respectively. Although intercropping significantly (p < 0.05) increased the abundance of bacteria and fungi, it did not change (p > 0.05) the abundance of protists. The Beta-diversity of fungi and protists were also affected (p < 0.05) by intercropping and irrigation, whereas the bacterial Beta-diversity did not change (p > 0.05). The network complexity and connection between protists and fungi under the IR treatment were higher than those under the MC treatment. Soil available nutrients and network topological indices such as edges linking protists to fungi were significantly positively correlated with potato production. Conclusions or significance: Common vetch intercropping with reduced irrigation could ensure potato tuber yield and quality, and improve soil quality, our research provides a sustainable cropping system suitable for potato cultivation in Inner Mongolia.

为提高内蒙古阴山北麓旱作农区水分利用效率,对比分析了生物炭和有机肥配施(BM)、生物炭(B)、有机肥(M)、不施生物炭和有机肥(CK)4种不同耕种方式对燕麦、全生育阶段土壤水分时空变化、土壤耗水特征及燕麦关键生育期农艺性状、产量构成和水分利用效率的影响.结果表明,生物炭和有机肥及两者配施均可促进燕麦生长发育,以灌浆期为例,与CK相比,B、M和BM处理下燕麦株高分别提高17.73％、22.29％和26.03％,单株叶面积分别提高13.32％、17.05％和23.67％,地上部干物质积累量分别提高6.48％、7.39％和20.30％,燕麦生育前中期生物炭效果优于有机肥,生育后期有机肥施用效果优于生物炭,两者耦合效果最好;BM处理可提高0～40 cm土壤含水量1.65％～19.12％,显著降低燕麦土壤贮水消耗11.34％～20.09％,总耗水量降低0.38％～0.88％,施用生物炭保水减耗效果强于有机肥,随着生育期推进和降水增加,两者效果差异逐渐减小;在产量方面,BM处理可同时显著提高收获穗数、穗粒数和单穗粒重,促进燕麦籽粒产量形成和水分利用,籽粒产量提高7.63％～14.80％,水分利用效率提高8.62％～16.64％.生物炭和有机肥配施可显著促进旱作燕麦生长,有效保持土壤水分,提高燕麦水分利用效率和产量,是适宜内蒙古阴山北麓地区旱作燕麦种植的抗旱保墒技术措施.

Increasing agricultural productivity and assessing the responses of soil properties in soils with different groups under intercropping are the key steps to meeting both forage demand and soil full utilization. The effect of intercropping oat ( Avena sativa L.) and common vetch ( Vicia sativa L.) on yield, soil nutrient availability in different soil textures was examined under five planting systems: sole common vetch (V), sole oat (O), or intercropped with common vetch at ratios 1:1, 2:1, and 3:1. The biomass in oat/common vetch intercropping 2:1 (OV2:1) and 3:1 was higher than that of other treatments except for monoculture oat. The soil available nitrogen (AN) of oat/common vetch intercropping 3:1 (OV3:1) was significantly ( P < 0.05) higher than O except for chernozem. However, the soil available phosphorus (AP) in OV2:1 was significantly increased by 34.89% and 17.93%, 29.18% and 43.74%, and 39.31% and 14.22% compared with the corresponding oat monoculture while available potassium in saline-alkali was 17.57% and 11.75%, and 13.36% and 7.93% significantly higher than corresponding oat and common vetch monoculture. These results suggest that oat intercropped with common vetch at 3:1 could acquire high biomass while 2:1 is beneficial to the improvement of soil quality.

In order to study the comprehensive effects of nitrogen reduction combined with different fertilizer applications on greenhouse gas emissions,nitrogen use efficiency and potato yield,seven treatments were set up:balanced application of nitrogen,phosphorus and potassium fertilizer(NPK,control),no nitrogen fertilizer(PK,blank),reduction of nitrogen application rate by 20%(RN,application rate of phosphorus and potassium fertilizer is the same as NPK),reduction of nitrogen application rate by 20%+ water-soluble fertilizer instead of 20%of total nitrogen application rate(RN + WF),reduction of nitrogen application rate by 20%+ decomposed sheep manure instead of 20%of total nitrogen application rate(RN + SM),reduction of nitrogen application rate by 20%+ bio-organic fertilizer instead of 20%of total nitrogen application rate(RN + BM),reduction of nitrogen application rate by 20%+ slow-release urea instead of 20%of total nitrogen application rate(RN + RUN)from 2020 to 2021.Effects of the seven treatments on greenhouse gas emissions from potato fields,global warming potential,yield and nitrogen use efficiency during the potato growing season were researched.The results showed that the reduction of nitrogen fertilizer and the combined application of different fertilizers could obviously affect the emission of greenhouse gases in farmland.In 2020 and 2021,the average emission fluxes of CO2 and N2O in RN + SM treatment were 10.97%-22.70%and 7.86%-14.66%higher than those in NPK treatment.The cumulative emissions of CO2,N2O and CH4 in RN + SM treatment were the largest,which were 9299.77-11401.35,3.65-3.77 and-1.35--1.20 kg/ha,respectively.The global warming potential(GWP)in RN + SM treatment was 36.10%-79.66%higher than that in NPK treatment.Nitrogen fertilizer reduction and combined application of different fertilizers could significantly increase potato yield and nitrogen use efficiency(P<0.05).Compared with NPK treatment,the partial factor productivity of applied nitrogen(PFPN)and nitrogen agronomic efficiency(NAE)in RN + BM treatment were significantly different(P<0.05),which increased by 46.19%-47.26%and 150.51%-236.38%,respectively,and the yield of potato increased by 16.95%-17.77%.Therefore,organic manure(sheep manure)could increase greenhouse gas emissions from farmland;biological organic fertilizer replacing part of nitrogen fertilizer could improve nitrogen use efficiency and potato yield,which should be recommended to be popularized and applied in potato production.

Key phenological periods of vegetation (such as the start (SOS) and end (EOS) of the growing season) are affected by climate change and human activities. However, the impact of aridification on these phenological responses is still unclear. In the farming-pastoral ecotone of northern China (FPENC), which is plagued by severe aridification, the climate change-dominant aridification zone (CDA), human activity-dominant aridification zone (HDA), and compound-dominant aridification zone (CHDA) were differentiated, and their phenological responses to different aridification types were studied via multiyear remote sensing inversion and meteorological data. Our results suggest that aridification significantly shortened the vegetation growing season, i.e., the SOS tended to be delayed (0.4-5.12 d/10a), and the EOS tended to be advanced (0-2.89 d/10a). In addition, the negative impact of CHDA, which had the highest aridification intensity, on phenological change was 3 to 4 times than that of CDA and twice than that of HDA. Thresholds were found in the phenological responses to climate change: in aridification areas, where the interannual warming rate exceeded 0.02-0.04 degrees C/a or the increased rate of interannual precipitation was less than 8 mm/a, prolonged growing seasons transitioned to shortened seasons. Furthermore, there was a nonlinear relationship between human activity contributions and phenological changes. When human activity contributions were between 40 and 70%, the growing season was significantly shortened. The extent of the SOS delay for cultivated land was greater than that for grassland, while the extent of the EOS advance was less for cultivated land than for grassland. Within the same climate zone, cultivated land phenological changes were stabilized by human activities, while grassland phenological changes under natural conditions were more severe and accompanied by signs of vegetation degradation. This study provides incremental knowledge for understanding the impacts of aridification on phenology and for adapting to aridification.