State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems

Kobresia (syn. Carex) pygmaea dominated pastures in the eastern Tibetan highlands are the world's largest pastoral alpine ecosystem forming a durable turf cover at 3000-6000 m a.s.l. Kobresia's resilience and competitiveness is based on dwarf habit, predominantly below-ground allocation of photo assimilates, mixture of seed production and clonal growth, and high genetic diversity. Kobresia growth is co-limited by livestock-mediated nutrient withdrawal and, in the drier parts of the plateau, low rainfall during the short and cold growing season. Overstocking has caused pasture degradation and soil deterioration over most parts of the Tibetan highlands and is the basis for this man-made ecosystem. Natural autocyclic processes of turf destruction and soil erosion are initiated through polygonal turf cover cracking, and accelerated by soil-dwelling endemic small mammals in the absence of predators. The major consequences of vegetation cover deterioration include the release of large amounts of C, earlier diurnal formation of clouds, and decreased surface temperatures. These effects decrease the recovery potential of Kobresia pastures and make them more vulnerable to anthropogenic pressure and climate change. Traditional migratory rangeland management was sustainable over millennia, and possibly still offers the best strategy to conserve and possibly increase C stocks in the Kobresia turf.

Abstract Nearly 90% of the 390 million ha of grasslands in northern China are degraded. ‘Grazing exclusion’ has been implemented as a nature‐based solution to rejuvenate degraded grasslands, but the effectiveness of the rejuvenation processes is uncertain. Here, we investigated the effects of grazing exclusion on aboveground plant community traits, soil physiochemical and biological properties, and the mechanisms responsible for enhanced grassland rejuvenation. A meta‐analysis across various studies was used to assess the effectiveness. On average, grazing exclusion improved vegetation coverage by 18.5 percentage points and increased aboveground biomass by 1.13 t ha −1 and root biomass by 1.27 t ha −1 , which represent an increase of 84%, 246%, and 31%, respectively, compared with continuous grazing practices. Grazing exclusion reduced soil bulk density by 13.7% and increased soil water content by 68.9%. Grasslands under grazing exclusion increased soil organic carbon (SOC) in the 0‐ to 15‐cm depth by 3.95 (±0.35 Std err) t ha −1 and total soil N, available N, and total soil P in the 0‐ to 40‐cm depth by 2.39 (±0.14), 0.83 (±0.37), and 1.96 (±0.44) t ha −1 , respectively, compared with continuous grazing; these values represent an increase of 31%, 25%, 23%, and 14%, respectively. Prolonging the duration (years) of grazing practices enlarged the differences in SOC and soil N content between grazing exclusion and continuous grazing. Grazing exclusion has improved plant community traits and enhanced soil physiochemical and biological properties of degraded grasslands, and thus, this ‘nature‐based’ approach can serve as an effective means to rejuvenate degraded grasslands.

The Zoige Plateau is typical of alpine wetland ecosystems worldwide, which play a key role in regulating global climate and ecological balance. Due to the influence of global climate change and intense human activities, the stability and sustainability of the ecosystems associated with the alpine marsh wetlands are facing enormous threats. It is important to establish a precise risk assessment method to evaluate the risks to alpine wetlands ecosystems, and then to understand the influencing factors of ecological risk. However, the multi-index evaluation method of ecological risk in the Zoige region is overly focused on marsh wetlands, and the smallest units of assessment are relatively large. Although recently developed landscape ecological risk assessment (ERA) methods can address the above limitations, the final directionality of the evaluation results is not clear. In this work, we used the landscape ERA method based on land use and land cover changes (LUCC) to evaluate the ecological risks to an alpine wetland ecosystem from a spatial pixel scale (5 km × 5 km). Furthermore, the boosted regression tree (BRT) model was adopted to quantitatively analyze the impact factors of ecological risk. The results show the following: (1) From 1990 to 2016, the land use and land cover (LULC) types in the study area changed markedly. In particular, the deep marshes and aeolian sediments, and whereas construction land areas changed dramatically, the alpine grassland changed relatively slowly. (2) The ecological risk in the study area increased and was dominated by regions with higher and moderate risk levels. Meanwhile, these areas showed notable spatio-temporal changes, significant spatial correlation, and a high degree of spatial aggregation. (3) The topographic distribution, climate changes and human activities influenced the stability of the study area. Elevation (23.4%) was the most important factor for ecological risk, followed by temperature (16.2%). Precipitation and GDP were also seen to be adverse factors affecting ecological risk, at levels of 13.0% and 12.1%, respectively. The aim of this study was to provide more precise and specific support for defining conservation objectives, and ecological management in alpine wetland ecosystems.

Enhancement of resource use efficiencies and crop productivity in sustainable agriculture are importantespecially in low-input production systems. This experiment was planned to evaluate the performance of maizeunder different water and nitrogen levels. Three irrigation treatments i.e., I1= three leaf stage (V1), nine leafstage (V2), tasseling (T) and milking stage (M); I2 = V1, V2, T, M and dough stage (R1), I3= V1, V2,T, M , R1 and blister stage (R2) were applied with 70 mm application depth with different nitrogen applicationrates i.e., 0 , 150, 200 and 250 kg N ha-1. Results revealed that maximum growth i.e., plant height, leaf areaindex (LAI), crop growth rate (CGR), cob length and diameter as well as yield and yield components i.e.,grains rows/cob, grains/row, grains/cob, grain weight/cob, 100-grain weight, grain yield, biological yield andharvest index, water and nitrogen use efficiencies as well as transpiration and photosynthetic activities wererecorded at I3 with 250 kg N ha-1. However, increased irrigation and nitrogen application rates delayed days totasseling, silking and maturity. Conclusively, six irrigations (I3) with 250 kg N ha-1 can be adopted as the bestinput levels to get maximum maize yield under semi-arid regions. In future both these inputs may be used aswater and nitrogen based agricultural best management practices (BMPs) in regions with similar type ofenvironmental conditions.

BACKGROUND: Elymus L. is the largest genus in the tribe Triticeae Dumort., encompassing approximately 150 polyploid perennial species widely distributed in the temperate regions of the world. It is considered to be an important gene pool for improving cereal crops. However, a shortage of molecular marker limits the efficiency and accuracy of genetic breeding for Elymus species. High-throughput transcriptome sequencing data is essential for gene discovery and molecular marker development. RESULTS: We obtained the transcriptome dataset of E. sibiricus, the type species of the genus Elymus, and identified a total of 8871 putative EST-SSRs from 6685 unigenes. Trinucleotides were the dominant repeat motif (4760, 53.66%), followed by dinucleotides (1993, 22.47%) and mononucleotides (1876, 21.15%). The most dominant trinucleotide repeat motif was CCG/CGG (1119, 23.5%). Sequencing of PCR products showed that the sequenced alleles from different Elymus species were homologous to the original SSR locus from which the primer was designed. Different types of tri-repeats as abundant SSR motifs were observed in repeat regions. Two hundred EST-SSR primer pairs were designed and selected to amplify ten DNA samples of Elymus species. Eighty-seven pairs of primer (43.5%) generated clear and reproducible bands with expected size, and showed good transferability across different Elymus species. Finally, thirty primer pairs successfully amplified ninety-five accessions of seventeen Elymus species, and detected significant amounts of polymorphism. In general, hexaploid Elymus species with genomes StStHHYY had a relatively higher level of genetic diversity (H = 0.219, I = 0.330, %P = 63.7), while tetraploid Elymus species with genomes StStYY had low level of genetic diversity (H = 0.182, I = 0.272, %P = 50.4) in the study. The cluster analysis showed that all ninety-five accessions were clustered into three major clusters. The accessions were grouped mainly according to their genomic components and origins. CONCLUSIONS: This study demonstrated that transcriptome sequencing is a fast and cost-effective approach to molecular marker development. These EST-SSR markers developed in this study are valuable tools for genetic diversity, evolutionary, and molecular breeding in E. sibiricus, and other Elymus species.

Although previous studies have shown that the construction of the China-Myanmar Economic Corridor (CMEC) has caused critical deforestation, few studies have monitored the long-term vegetation dynamics in corridor regions. Recent studies have revealed vegetation greening trends at different scales but have failed to further explore whether these trends are due to the restoration of natural vegetation or the large-scale planting of artificial crops. To investigate the vegetation dynamics and influencing factors during the growing season between 2001 and 2020 in the CMEC area, trend analysis, the random forest (RF) classifier at Google Earth Engine platform, and the geographic detector were employed to quantitatively analyze the patterns of distribution and change in vegetation coverage and its driving factors. Note that we distinguished between natural vegetation areas and artificial crop areas using the RF classification algorithm in an attempt to improve the drawback that most previous studies confused the contribution of natural vegetation and artificial vegetation to macro vegetation change. We discovered that (1) the growing-season average fractional vegetation cover (FVC) was 0.7033, which was relatively low in central and southern regions. The FVC increased by 0.21% yr−1 from 2001 to 2020, and areas with an increasing trend in FVC were 16.67% more than those with a decreasing trend. (2) Although forests and grasslands were reduced by 0.68%, the cropland that prominently clustered in the central and southern regions contributed 50.37% to an increase in FVC, and the decreasing effects on natural vegetation were offset by the increase in artificial crops. (4) The factors that influence FVC distribution were ranked in descending order: land use/land cover (LULC) > climate > topography > anthropogenic activity; factors that influence FVC change were ranked as: anthropogenic activity > climate > LUCC. Note that the grain yield influence on the FVC distribution increased 0.31% yr -1, which was also the most important factor driving FVC change, indicating that agricultural activities increasingly facilitated vegetation greening.

SMALL AUXIN-UP RNAs (SAURs) comprise the largest family of early auxin response genes. Some SAURs have been reported to play important roles in plant growth and development, but their functional relationships with auxin signaling remain unestablished. Here, we report Arabidopsis (Arabidopsis thaliana) SAUR15 acts downstream of the auxin response factors ARF6,8 and ARF7,19 to regulate auxin signaling-mediated lateral root (LR) and adventitious root (AR) formation. The lossof-function mutant saur15-1 exhibits fewer LRs and ARs. By contrast, plants overexpressing SAUR15 exhibit more LRs and ARs. We find that the SAUR15 promoter contains four tandem auxin-responsive elements, which are directly bound by ARF6 and ARF7 and are essential for SAUR15 expression. LR and AR impairment in arf6 and arf7 mutants is partially reduced by ectopic expression of SAUR15. Additionally, we demonstrate that the ARF6,7-upregulated SAUR15 promotes LR and AR development using two mechanisms. On the one hand, SAUR15 interacts with PP2C-D subfamily type 2C protein phosphatases to inhibit their activities, thereby stimulating plasma membrane H 1 -ATPases, which drives cell expansion and facilitates LR and AR formation. On the other hand, SAUR15 promotes auxin accumulation, potentially by inducing the expression of auxin biosynthesis genes. A resulting increase in free auxin concentration likely triggers LR and AR formation, forming a feedback loop. Our study provides insights and a better understanding of how SAURs function at the molecular level in regulating auxinmediated LR and AR development.

BACKGROUND: Elymus sibiricus is an ecologically and economically important perennial, self-pollinated, and allotetraploid (StStHH) grass, widely used for forage production and animal husbandry in Western and Northern China. However, it has low seed yield mainly caused by seed shattering, which makes seed production difficult for this species. The goals of this study were to construct the high-density genetic linkage map, and to identify QTLs and candidate genes for seed-yield related traits. RESULTS: mapping population of 200 individuals was developed from a cross between single genotype from "Y1005" and "ZhN06". Specific-locus amplified fragment sequencing (SLAF-seq) was applied to construct the first genetic linkage map. The final genetic map included 1971 markers on the 14 linkage groups (LGs) and was 1866.35 cM in total. The length of each linkage group varied from 87.67 cM (LG7) to 183.45 cM (LG1), with an average distance of 1.66 cM between adjacent markers. The marker sequences of E. sibiricus were compared to two grass genomes and showed 1556 (79%) markers mapped to wheat, 1380 (70%) to barley. Phenotypic data of eight seed-related traits (2016-2018) were used for QTL identification. A total of 29 QTLs were detected for eight seed-related traits on 14 linkage groups, of which 16 QTLs could be consistently detected for two or three years. A total of 6 QTLs were associated with seed shattering. Based on annotation with wheat and barley genome and transcriptome data of abscission zone in E. sibiricus, we identified 30 candidate genes for seed shattering, of which 15, 7, 6 and 2 genes were involved in plant hormone signal transcription, transcription factor, hydrolase activity and lignin biosynthetic pathway, respectively. CONCLUSION: This study constructed the first high-density genetic linkage map and identified QTLs and candidate genes for seed-related traits in E. sibiricus. Results of this study will not only serve as genome-wide resources for gene/QTL fine mapping, but also provide a genetic framework for anchoring sequence scaffolds on chromosomes in future genome sequence assembly of E. sibiricus.

PREMISE OF THE STUDY: Temperature and water potential for germination based on the thermal and hydrotime models have been successfully applied in predicting germination requirements of physiologically dormant seeds as well as nondormant seeds. However, comparative studies of the germination requirements of physically dormant seeds from different ecosystems have not been done. METHODS: Germination of scarified seeds of four legume species collected from the Qing-Tibetan Plateau and of four collected in the Alax Desert in China was compared over a range of temperatures and water potentials based on thermal time and hydrotime models. KEY RESULTS: Seeds of species from the Qing-Tibetan Plateau had a lower base temperature (T b) and optimal temperature (T o) for germination than those from the Alax Desert. Seeds of the four species from the Qing-Tibetan Plateau germinated to high percentages at 5°C, whereas none of the four desert species did so. Seeds of species from the Alax Desert germinated to a high percentage at 35°C or 40°C, while no seeds of species from the Qing-Tibetan Plateau germinated at 35°C or 40°C. The base median water potential [Ψ b(50)] differed among species but not between the two habitats. CONCLUSIONS: The thermal time and hydrotime models accurately predicted the germination time course of scarified seeds of most of the eight species in response to temperature and water potential; thus, they can be useful tools in comparative studies on germination of seeds with physical dormancy. Habitat temperatures but not rainfall is closely related to germination requirements of these species.

BACKGROUND: Variants that regulate transcription, such as expression quantitative trait loci (eQTL), have shown enrichment in genome-wide association studies (GWAS) for mammalian complex traits. However, no study has reported eQTL in sheep, although it is an important agricultural species for which many GWAS of complex meat traits have been conducted. Using RNA sequence data produced from liver and muscle from 149 sheep and imputed whole-genome single nucleotide polymorphisms (SNPs), our aim was to dissect the genetic architecture of the transcriptome by associating sheep genotypes with three major molecular phenotypes including gene expression (geQTL), exon expression (eeQTL) and RNA splicing (sQTL). We also examined these three types of eQTL for their enrichment in GWAS of multi-meat traits and fatty acid profiles. RESULTS: > 0, P < 0.05), their mean heritability ranged from 0.67 to 0.73 for liver and from 0.71 to 0.77 for muscle. Association analysis between molecular phenotypes and SNPs within ± 1 Mb identified many significant cis-eQTL (false discovery rate, FDR < 0.01). The median distance between the eQTL and transcription start sites (TSS) ranged from 68 to 153 kb across the three eQTL types. The number of common variants between geQTL, eeQTL and sQTL within each tissue, and the number of common variants between liver and muscle within each eQTL type were all significantly (P < 0.05) larger than expected by chance. The identified eQTL were significantly (P < 0.05) enriched in GWAS hits associated with 56 carcass traits and fatty acid profiles. For example, several geQTL in muscle mapped to the FAM184B gene, hundreds of sQTL in liver and muscle mapped to the CAST gene, and hundreds of sQTL in liver mapped to the C6 gene. These three genes are associated with body composition or fatty acid profiles. CONCLUSIONS: We detected a large number of significant eQTL and found that the overlap of variants between eQTL types and tissues was prevalent. Many eQTL were also QTL for meat traits. Our study fills a gap in the knowledge on the regulatory variants and their role in complex traits for the sheep model.

Abstract Background Heritable rumen microbiota is an important modulator of ruminant growth performance. However, no information exists to date on host genetics-rumen microbiota interactions and their association with phenotype in sheep. To solve this, we curated and analyzed whole-genome resequencing genotypes, 16S rumen-microbiota data, and longitudinal body weight (BW) phenotypes from 1150 sheep. Results A variance component model indicated significant heritability of rumen microbial community diversity. Genome-wide association studies (GWAS) using microbial features as traits identified 411 loci-taxon significant associations ( P &lt; 10 −8 ). We found a heritability of 39% for 180-day-old BW, while also the rumen microbiota likely played a significant role, explaining that 20% of the phenotypic variation. Microbiota-wide association studies (MWAS) and GWAS identified four marker genera (Bonferroni corrected P &lt; 0.05) and five novel genetic variants ( P &lt; 10 −8 ) that were significantly associated with BW. Integrative analysis identified the mediating role of marker genera in genotype influencing phenotype and unravelled that the same genetic markers have direct and indirect effects on sheep weight. Conclusions This study reveals a reciprocal interplay among host genetic variations, the rumen microbiota and the body weight traits of sheep. The information obtained provide insights into the diverse microbiota characteristics of rumen and may help in designing precision microbiota management strategies for controlling and manipulating sheep rumen microbiota to increase productivity.

To inform the further development of water pricing in Shiyang River basin, a typical arid region in northwest China with agriculture as the major consumer of water, this research conducted a contingent valuation study on farmer’s willingness to pay (WTP) for irrigation water. The results show that the current irrigation water price is to low to achieve sustainable use of water. The main reason of low price is not the farmer’s inability to pay, but their unwillingness to pay. Furthermore, a vicious cycle of less willingness to pay and poor services exist in irrigation water management. The probable solutions include the increase of public investment in water infrastructure and determine appropriate price between surface water and groundwater. More important, enhance the communication and cooperation between water use and water agency, the combination of price mechanism and other instruments, such as positive incentives and the establishment of an independent water user organization (WUO), are useful.

Abstract Dryland mountain ecosystems regulate global terrestrial carbon cycling and show high sensitivity to climate variability. The Qilian Mountains (QLMs) typify dryland mountain ranges in northern temperate belts and offer fundamental ecosystem services including forage production and water conservation. However, dominant controls on the interannual trend and variability of net primary productivity (NPP) in this region are unknown. Thus, we examined magnitude and direction of the NPP trend and quantified NPP sensitivity to temperature and precipitation under different biomes and altitudes using ground and remote sensing data. Our results showed that 12% of the QLMs had a reversed NPP trend from increasing to decreasing from 2000 to 2016, particularly in the western and southern parts, where NPP reductions were related to precipitation deficits. About 34% of the QLMs showed accelerated or persistent increasing NPP trends, mainly from the mid‐altitude between 3,100 and 4,300 m. The growth rate of NPP was higher in deserts and grasslands than in forests and increased in deserts but decreased in forests and grasslands with increasing elevation. Precipitation showed a stronger effect on the interannual variability in NPP than temperature did. The temperature sensitivity of NPP was similar along elevation gradients in forest steppes but decreased with increasing elevation in alpine deserts. The precipitation sensitivity of NPP reached highest in shrubby meadows when compared with coniferous forests and alpine deserts. This research provides new insights into climate controls of the NPP over the QLMs and to present drought as a growing threat to shrubby meadows and alpine deserts.

Abstract Background Inputs of above- and belowground litter into forest soils are changing at an unprecedented rate due to continuing human disturbances and climate change. Microorganisms drive the soil carbon (C) cycle, but the roles of above- and belowground litter in regulating the soil microbial community have not been evaluated at a global scale. Methods Here, we conducted a meta-analysis based on 68 aboveground litter removal and root exclusion studies across forest ecosystems to quantify the roles of above- and belowground litter on soil microbial community and compare their relative importance. Results Aboveground litter removal significantly declined soil microbial biomass by 4.9% but root exclusion inhibited it stronger, up to 11.7%. Moreover, the aboveground litter removal significantly raised fungi by 10.1% without altering bacteria, leading to a 46.7% increase in the fungi-to-bacteria (F/B) ratio. Differently, root exclusion significantly decreased the fungi by 26.2% but increased the bacteria by 5.7%, causing a 13.3% decrease in the F/B ratio. Specifically, root exclusion significantly inhibited arbuscular mycorrhizal fungi, ectomycorrhizal fungi, and actinomycetes by 22.9%, 43.8%, and 7.9%, respectively. The negative effects of aboveground litter removal on microbial biomass increased with mean annual temperature and precipitation, whereas that of root exclusion on microbial biomass did not change with climatic factors but amplified with treatment duration. More importantly, greater effects of root exclusion on microbial biomass than aboveground litter removal were consistent across diverse forest biomes (expect boreal forests) and durations. Conclusions These data provide a global evidence that root litter inputs exert a larger control on microbial biomass than aboveground litter inputs in forest ecosystems. Our study also highlights that changes in above- and belowground litter inputs could alter soil C stability differently by shifting the microbial community structure in the opposite direction. These findings are useful for predicting microbe-mediated C processes in response to changes in forest management or climate.

Abstract. This study develops a model for early warning of snow-caused livestock disasters on a county basis and proposes a method of qualitative risk assessment of snow disasters at 500 m resolution for pastoral areas on the Tibetan Plateau (TP). Data used for the model development include remote sensing data, statistical data of weather, livestock, and social economy, and 45 typical snow disaster cases from 2000 to 2010. The principal component analysis (PCA) approach is used to choose 7 crucial factors that contribute over 85% of information for early warning snow disasters on the TP. They are mean annual probability of snow disaster, number of snow-covered days, livestock stocking rate, continual days of mean daily temperature below −10 °C, grassland burial index, rate of snow-covered grassland, and per livestock gross domestic product. The chosen 411 cases from 2008 to 2010 are used to validate the prediction results from the developed early warning model, with an overall accuracy of 85.64% in predicting snow disasters and no disasters. This suggests that the early warning approach developed in the study has operational potential for predicting snow disasters on the TP.

Core Ideas The optimal N rate was about 100 kg ha −1 yr −1 . Best duration for fertilization is less than 10 yr. The application of NPKM demonstrates the greatest potential for increasing microbial biomass in China's cropland. Soil microbial biomass (SMB) plays an important role in enhancing soil aggregation, promoting nutrient cycling, and making a substantial contribution to soil organic matter. Little is known about the underlying mechanism and broad‐scale responses of SMB to long‐term fertilization practices on a regional scale. The objective of this study is to characterize changes in SMB of predominant cropping systems in China (mainly producing maize [ Zea mays L.], wheat [ Triticum aestivum L.], rice [ Oryza sativa L.], and soybean [ Glycine max L.]) under different fertilization regimes using meta‐analysis. We integrated data from more than 60 studies conducted in China from 1990 to 2015 and found that application of inorganic fertilizer, straw, straw with inorganic fertilizer, manure, and manure with inorganic fertilizer increased soil microbial biomass carbon (C mic ) concentration, while nitrogen‐only (N) and nitrogen plus manure (NM) decreased soil microbial biomass nitrogen (N mic ) concentration compared with control (no fertilizer application). Our results indicated greater C mic and N mic responses to inorganic N, P, and K‐based fertilizers plus manure (NPKM) in the mid‐latitude region compared with those in the low‐ and high‐latitude regions of China. The differences in means (C mic or N mic concentration) among different fertilization treatments decreased with experimental duration, and N mic concentration decreased with increase in N rate. Our results suggested that long‐term (∼10 yr) continuous annual fertilization of N provided the greatest SMB, and the optimal rate was about 100 kg N ha −1 yr −1 . The application of NPKM demonstrated the greatest potential for increasing SMB of major cropping systems in China.

Remote sensing data have been widely used in the study of large-scale vegetation activities, which have important significance in estimating grassland yields, determining grassland carrying capacity, and strengthening the scientific management of grasslands. Remote sensing data are also used for estimating grazing intensity. Unfortunately, the spatial distribution of grazing-induced degradation remains undocumented by field observation, and most previous studies on grazing intensity have been qualitative. In our study, we tried to quantify grazing intensity using remote sensing techniques. To achieve this goal, we conducted field experiments at Gansu Province, China, which included a meadow steppe and a semi-arid region. The correlation between a vegetation index and grazing intensity was simulated, and the results demonstrated that there was a significant negative correlation between NDVI and relative grazing intensity (p &lt; 0.05). The relative grazing intensity increased with a decrease in NDVI, and when the relative grazing intensity reached a certain level, the response of NDVI to relative grazing intensity was no longer sensitive. This study shows that the NDVI model can illustrate the feasibility of using a vegetation index to monitor the grazing intensity of livestock in free-grazing mode. Notably, it is feasible to use the remote sensing vegetation index to obtain the thresholds of livestock grazing intensity.

Core Ideas The highest yield and water‐use efficiency were under plastic mulching and the lowest in conventional practice. Maize yields were more sensitive to soil water at sowing under mulching and subsoiling tillage practices in the Loess Plateau. The synthesis demonstrates that ridge furrow mulching was the optimum practice for maximizing maize yield. Mulching and tillage practices is widely used to increase crop productivity and reduce water evaporation in semiarid regions. This study was conducted to determine which management practice was optimal through improving grain yield and water‐use efficiency (WUE). Based on an analysis of 44 recent publications, we synthesized maize ( Zea mays L) yield, WUE, and evapotranspiration (ET) in response to ridge furrow mulching (RFM), flat mulching (FM), straw mulching (SM), mulching with other materials (MOM), mulching with two materials combined (MTMC), rotational tillage (RT), no‐tillage (NT), and subsoiling tillage (ST) on the Loess Plateau at a broad scale. Yield ranged from 1.0 to 14.6 t ha −1 , WUE from 0.30 to 5.70 kg m −3 , and ET from 158 to 660 mm under mulching practices; yield ranged from 5.19 to 11.92 t ha −1 , WUE from 1.45 to 3.43 kg m −3 , and ET from 308 to 556 mm under tillage practices. The maximum yield and WUE were achieved under RFM (ridge and furrow mulched with plastic film) the minimum under conventional tillage (CT). Maize yield is largely related to soil water storage (SWS) at sowing under RFM, FM, SM, MOM, MTMC, and ST practices compared to NT and RT. Ridge furrow mulching and ST increased the maize yields by 58 and 9%, respectively, and corresponding for WUE by 61 and 9%. Therefore, we suggested that increasing the capture of soil water storage (SWS) at maize sowing and encouraging use of RFM practice to improve grain yield and WUE in this region.

Eupatorium adenophorum has caused tremendous ecological and economic losses in China since the 1940s. Although a great deal of money has been expended on the prevention and control of the weed, the situation is still deteriorating. To identify its crucial environmental constraints, an ecological niche factor analysis was employed. The distribution of the weed was predicted by the maximum entropy model. The results indicate that the temperature in winter is more influential than that in other quarters of a year, and the maximum temperature in March restricts the spread of E. adenophorum most. Currently, the weed is mainly distributed in four provinces of southwest China. From the present to the 2080s, the center of L3, which has a potential distribution probability of 0.7 to 1.0, will move 53 km to the southwest. Accordingly, the area of L3 will expand by 16.04%. To prevent its further expansion, we suggest differentiating the prevention and control measures according to the potential distribution levels predicted. Meanwhile, the integration of various means of removal and comprehensive utilization of E. adenophorum is highly encouraged. Additionally, precautions should be taken in regions that have not yet, or have been only slightly, invaded by the E. adenophorum.

BACKGROUND: Zygophyllum xanthoxylum is a succulent xerophyte with remarkable tolerance to diverse abiotic stresses. Previous studies have revealed important physiological mechanisms and identified functional genes associated with stress tolerance. However, knowledge of the regulatory genes conferring stress tolerance in this species is poorly understood. RESULTS: Here, we present a comprehensive analysis of regulatory genes based on the transcriptome of Z. xanthoxylum roots exposed to osmotic stress and salt treatments. Significant changes were observed in transcripts related to known and obscure stress-related hormone signaling pathways, in particular abscisic acid and auxin. Significant changes were also found among key classes of early response regulatory genes encoding protein kinases, transcription factors, and ubiquitin-mediated proteolysis machinery. Network analysis shows a highly integrated matrix formed by these conserved and novel gene products associated with osmotic stress and salt in Z. xanthoxylum. Among them, two previously uncharacterized NAC (NAM/ATAF/CUC) transcription factor genes, ZxNAC083 (Unigene16368_All) and ZxNAC035 (CL6534.Contig1_All), conferred tolerance to salt and drought stress when constitutively overexpressed in Arabidopsis plants. CONCLUSIONS: This study provides a unique framework for understanding osmotic stress and salt adaptation in Z. xanthoxylum including novel gene targets for engineering stress tolerance in susceptible crop species.