Low-carbon technologies are pivotal for boosting rice yields while cutting greenhouse gas emissions in paddies. Microalgae biofertilizer offers great potential for enhancing soil fertility and crop productivity. However, few studies have addressed its effects on greenhouse gas emissions and the underlying mechanisms in paddy soil. Here, a greenhouse pot experiment was conducted to investigate the effects of microalgae biofertilizer on greenhouse gas emissions from paddy soil. The experiment designed four treatments, including N100 (full chemical nitrogen fertilizer), N80 (20

Nitrogen (N) fertilization critically regulates the storage and availability of soil carbon (C) and N pools. However, the internal mechanism through which stratified N application affects soil organic carbon (SOC) sequestration and soil quality index (SQI) remains unclear. To investigate the effects of stratified N application on C sequestration and SQI in both topsoil and subsoil, this study established six treatments (N0:0, N1:0, N4:1, N3:2, N2:3, N1:4) and analyzed soil biochemical indicators. The results showed that compared to N1:0, stratified N fertilization did not significantly improve soil C and N content in the 0–20 cm layer. In contrast, the N2:3 and N1:4 treatments even led to a significant reduction in soil C and N pools in the topsoil. In the 20–40 cm, compared to N1:0, stratified N fertilization increased SOC, TN, labile C fractions, N fractions (particulate organic N and microbial biomass N), enzyme activity and C pool management index (CPMI), increasing by 0.52–7.94%, 2.05–8.42%, 4.77–42.59%, 14.46–56.01%, 6.34–45.82%, and 31.26–51.93%, respectively. In 0–20 cm, compared to N0:0, N application increased SQI by 24.84–45.77%, and N2:3 and N1:4 treatments were lower SQI than N1:0. Furthermore, N2:3, N3:2, and N1:4 treatments in 20–40 cm were higher than other treatments. N fertilizer application drives the synergistic changes in C and N fractions by regulating enzyme activity and stoichiometric ratio, thus affecting CPMI and SQI. Thus, the 3:2 stratified N fertilization (0–20 cm:20–40 cm) method achieves synergistic dual-layer enhancement-maintaining surface C and N pools while boosting subsoil C sequestration and quality-through enzyme-mediated precision regulation of C/N stoichiometry. The study provides a scientific foundation for integrated C emission reduction and cropland quality enhancement in the North China.

Carbon sequestration and emission reduction in apple cultivation are of great significance for achieving sustainable agricultural development and combating climate change. However, the status of carbon emissions from apple cultivation is unclear, and this study will provide implications for the agriculture sector. This study applied the life cycle assessment method to quantify carbon emissions and analysed the footprint composition of apple orchards in China, and identified the emissions peak based on the Mann-Kendall analysis. The results showed that the carbon emissions of apple cultivation reached the carbon peak in 2014. The carbon emissions per unit area (CEA) and per unit yield (CEY) were 5.79 t CO2eq ha-1 and 0.23 kg CO2eq kg-1 in 2021, respectively. Carbon emissions from fertilizers (54.4%) and irrigation electricity (30.9%) were identified as the dominant components in apple orchards. Specifically, Henan and Shandong exhibited higher growing advantages, characterized by higher carbon economic efficiency and lower CEY. The carbon emissions of the ideal scenario will be decreased 69.6% through optimizing fertilizers and energy restructuring. In conclusion, promoting low-carbon development in apple orchards can be achieved through targeted in-field mitigation measures, such as optimizing the amount and types of fertilizers, and adopting new energy for agricultural machinery.

Due to global warming, extreme climate events such as heat waves and storms will become more and more frequent, which would lead to huge losses including human health, the economy, water resources, ecosystems, and so on. Facing a grave situation, adaptation is becoming more and more important for each country or each person. As a big developing country, China has made great efforts in the past decades; (1) a national climate change response coordination organization and a climate change management system and working mechanism have been established; (2) the law on climate change in China is under preparation and to be issued; (3) a climate change adaptation policy system from top to bottom, expanding from comprehensive departments to professional departments has been gradually formed; (4) a large number of regulations and actions related to climate change adaptation have been successively issued and implemented by local government departments; (5) especially the rural community adaptation actions should be paid more attention and given more support. In order to make the “2030 carbon peak, 2060 carbon neutral” come true, the whole country should put more attention and efforts into adaptation, including more funds, more personnel, more programs, more actions, and so on; the adaptation policies and actions should be more detailed and specific; the effects of adaptation should be monitored and evaluated in the whole process.

Peanut and rapeseed oil, prominent edible oils in China, significantly contribute to greenhouse gas and reactive nitrogen emissions. A comprehensive examination of their environmental footprints is foundational for developing green and low-carbon products. Using a cradle-to-factory gate life cycle assessment, we quantified the carbon footprint (CF) and nitrogen footprint (NF) associated with the oil production of peanut and rapeseed from 2004 to 2023 in China. The results showed that peanut oil has a lower environmental impact than rapeseed oil, with a CF of 3,312.2 kg CO2eq t-1 oil and NF of 28.5 kg reactive nitrogen (Nr) t-1 oil, respectively, compared to 3,722.4 kg CO2eq t-1 oil and 43.3 kg Nr t-1 oil for rapeseed oil. It corresponded to less than 11.0% in CF and 34.2% in NF of peanut oil than that of rapeseed oil. The cropping phase was the primary source of disparity between the two oil products, with peanut exhibiting consistently lower yield-based CF and NF than rapeseed. Fertilizer application, primarily nitrogen (N) and compound fertilizers, accounted for 63.7% (peanut) and 91.4% (rapeseed) of CF, meanwhile N runoff and ammonia (NH3) volatilization were dominant in NF. Moreover, regions such as Jiangxi (peanut) and Yunnan, Shaanxi, and Gansu (rapeseed) exhibited high CF and NF but low productivity, suggesting the need for cropping layout optimization. Our findings highlight the environmental advantages of peanut oil, and recommend improved fertilizer management in agricultural stage and cleaner oil processing production to promote low-carbon, sustainable edible oil production in China.

Low-carbon production and consumption of rice constitute pivotal pathways toward achieving sustainable agricultural development. This study employed a life cycle assessment approach to systematically evaluate the carbon footprint (CF) and nitrogen footprint (NF) associated with indica and japonica rice in China, while concurrently conducting a comprehensive cost–benefit analysis. The results demonstrated that late indica rice exhibited higher carbon footprint per unit yield (CFy) and nitrogen footprint (NFy) compared to others. Temporal analysis revealed a notable 7.14–17.45

China is a world leading mandarin and tangerine producer, and the carbon emissions of mandarin and tangerine directly affect the characteristics and peak time of China’s agricultural carbon emissions. This study applied the life cycle assessment method to calculate the carbon emissions during the planting process of China’s mandarin and tangerine, and evaluated their carbon peak state and analyzed the planting advantages of different provinces based on the carbon economic efficiency (CEE) index. The results indicated that, the averaged carbon emissions per unit area (CA) and per yield (CY) of mandarin in 2020 were 13.9

Elevated atmospheric carbon dioxide (CO2) concentration generally stimulates nitrous oxide (N2O) emissions from upland soils, leading to a promoted feedback on climate change. However, the underlying mechanisms on how elevated CO2 (eCO2) stimulates N2O emissions from nitrogen (N)-fertilized upland soils remain poorly known. Here, we investigated the effects of eCO2 on soil N2O production pathways and associated gross N transformation rates, as well as on nitrifying and denitrifying microbes. Based on a 13 years of free-air CO2 enrichment (FACE) platform, we found that N2O emissions were significantly increased by 46.7% under eCO2 in a typical summer-maize field. The 15N tracing experiment showed that autotrophic nitrification rate was significantly increased by 11.6% under eCO2, coincided with the significantly higher abundance and shift composition of ammonia-oxidizing bacteria (AOB) under eCO2. Also, eCO2 enhanced gross ammonium (NH4+) immobilization rate but reduced gross nitrate (NO3−) immobilization rate. Autotrophic nitrification accounted for approximately 78% of N2O emissions, followed by heterotrophic nitrification (about 19%) and denitrification (about 3%). It was found that eCO2 increased carbon (C) deposition in soil, which could affect the availability of soil labile organic C and N and alter the composition and activity of nitrifiers. These changes promoted the N2O production derived from autotrophic nitrification, resulting in higher N2O emissions under eCO2. We could deduce that nitrifier denitrification contributed to the increased N2O emissions greatly under eCO2, derived by strongly stimulated ammonia oxidation and microbial respiration (i.e. higher soil CO2 emissions) caused suboxic conditions (i.e. lower soil oxygen (O2) concentration), along with higher abundance ratios of (nirK+nirS)/nosZ. Our results suggest that controlling autotrophic nitrification appropriately is crucial for mitigating N2O emissions from upland soils under rising atmospheric CO2 concentration.

AbstractDrought is more frequent and intensified due to global warming. Changed conditions in Beijing‐Tianjin–Hebei region which is drier and warmer than before, make it necessary to investigate various optimized irrigation schemes in the winter wheat production. In this study, the DSSAT–CERES‐Wheat model verified by field experimental data was applied to simulate the yield of winter wheat in Beijing–Tianjin–Hebei region from 2010 to 2069a under RCP8.5 climate scenario. The irrigation schemes were set up by adjusting the irrigation amount and irrigation structure to evaluate their adaptive capacity to climate change. The results showed that the regional average yield reduction rates of potential drought were 81.98% and 78.86% in 2010–2039a and 2040–2069a, which were higher in the north than that in the south. The yield reduction rate of potential drought increased with the decrease of irrigation amount, and the adaptive capacity declined with the decrease of irrigation amount, under the same irrigation structure. When 3‐9‐6 irrigation structure was applied, the regional averages of adaptive capacity to potential drought were 28.30%, 26.23%, and 22.22% in 2010–2039a, 29.00%, 26.67%, and 21.76% in 2040–2069a. The shortage of water resources caused by climate change and the possibility of drought limit the potential yield of winter wheat as high as 80% in this region. Priority shall be given to meeting the water demand in jointing stage and filling stage. Irrigation scheme of 3‐9‐6 structure with 180 mm irrigation amount shall be recommended and its adaptive capacity to climate change is the strongest in the near term and the medium‐term. Even if a further 20% reduction in irrigation is applied (144 mm), the dual goals of reducing yield loss and saving 8.28 × 108 t irrigation water per winter wheat season can be achieved.

Sugar is the main nutrient source of human beings and the basic raw material of the food industry. It is of great practical significance for China to find out the current situation and future trend of Greenhouse Gas (GHG) emissions from sugar production, and explore measures for reducing GHG emissions from sugar planting and processing. The IPCC GHG emissions accounting method is applied to analyze the carbon footprint of sugar production based on planting management and industrial development data, in which the GHG emissions per unit of sugar product are calculated and analyzed. According to Carbon Peak and Carbon Neutrality targets, the total GHG emissions of China's sugar industry in 2030 and 2060 are predicted and discussed. The results show that: (1) The average GHG emissions per unit yield of sugar show a downward trend from 2004 to 2021. The total GHG emissions of sugar production in China have reached 1319.9 x 104 t CO2eq in 2021, which has not yet reached its peak due to the growth of consumption demand. (2) The average GHG emissions per unit of Beet Sugar (1.477 tCO2eq/t) is higher than that of Cane Sugar (0.825 tCO2eq/t). It is more meaningful to enlarge the planting area of sugarcane than that of sugarbeet in the future. (3) Overall, in 2021 the GHG emissions of sugar production reached 0.91 tCO2eq/t in China, which would decline 15 %-87 % until 2030 and 2060. There is great potential for sugar production to reduce GHG emissions in the future.

AbstractElevated CO2 (eCO2) stimulates productivity and nutrient demand of crops. Thus, comprehensively understanding the crop phosphorus (P) acquisition strategy is critical for sustaining agriculture to combat climate changes. Here, wheat (Triticum aestivum L) was planted in field in the eCO2 (550 µmol mol−1) and ambient CO2 (aCO2, 415 µmol mol−1) environments. We assessed the soil P fractions, root morphological and physiological traits and multitrophic microbiota [including arbuscular mycorrhizal fungi (AMF), alkaline phosphomonoesterase (ALP)‐producing bacteria, protozoa, and bacterivorous and fungivorous nematodes] in the rhizosphere and their trophic interactions at jointing stage of wheat. Compared with aCO2, significant 20.2% higher shoot biomass and 26.8% total P accumulation of wheat occurred under eCO2. The eCO2 promoted wheat root length and AMF hyphal biomass, and increased the concentration of organic acid anions and the ALP activity, which was accompanied by significant decreases in calcium‐bound inorganic P (Ca‐Pi) (by 16.7%) and moderately labile organic P (by 26.5%) and an increase in available P (by 14.4%) in the rhizosphere soil. The eCO2 also increased the growth of ALP‐producing bacteria, protozoa, and bacterivorous and fungivorous nematodes in the rhizosphere, governed their diversity and community composition. In addition, the eCO2 strengthened the trophic interactions of microbiota in rhizosphere; specifically, the eCO2 promoted the associations between protozoa and ALP‐producing bacteria, between protozoa and AMF, whereas decreased the associations between ALP‐producing bacteria and nematodes. Our findings highlighted the important role of root traits and multitrophic interactions among microbiota in modulating crop P‐acquisition strategies, which could advance our understanding about optimal P management in agriculture systems under global climate changes.

Soil organic carbon (SOC) dynamics under elevated atmospheric CO2 concentration has been widely reported, however, in which the behaviors of active and passive fractions remain inadequately explored. Here we studied this issue using three pairs of active and passive fractions of SOC under a 10-year free-air CO2 enrichment experiment (550 ​± ​17 ​ppm) in a cropland in the North China Plain. We found that decadal elevated CO2 increased the root biomass, root exudation rate and microbial biomass, but had little effects on SOC pool size. Elevated CO2 increased the readily oxidizable organic carbon (ROOC) and particulate organic carbon (POC) due to the increments of root C input, but decreased their paired passive fractions possibly because of the carbon input-induced positive priming effect. Our results indicate the reduced stability of SOC pool under elevated CO2. This is significant for better predicting SOC feedback to future climate change.

Raising attentions have focused on how to alleviate greenhouse gas (GHG) emissions from orchard system while simultaneously increase fruit production. Microalgae-based biofertilizer represents a promising resource for improving soil fertility and higher productivity. However, the effects of microalgae application more especially live microalgae on GHG emissions are understudied. In this study, fruit yield and quality, GHG emissions, as well as soil organic carbon and nitrogen fractions were examined in a hawthorn orchard, under the effects of live microalgae-based biofertilizer applied at three doses and two modes. Compared with conventional fertilization, microalgae improved hawthorn yield by 15.7%-29.6% with a maximal increment at medium dose by root application, and significantly increased soluble and reducing sugars contents at high dose. While microalgae did not increase GHG emissions except for nitrous oxide at high dose by root application, instead it significantly increased methane uptake by 1.5-2.3 times in root application. In addition, microalgae showed an increasing trend in soil organic carbon content, and significantly increased the contents of soil dissolved organic carbon and microbial biomass carbon, as well as soil ammonium nitrogen and dissolved organic nitrogen at medium dose with root application. Overall, the results indicated that the live microalgae could be used as a green biofertilizer for improving fruit yield without increasing GHG emissions intensity and the comprehensive greenhouse effect, in particular at medium dose with root application. We presume that if lowering chemical fertilizer rates, application of the live microalgae-based biofertilizer may help to reduce nitrous oxide emissions without compromising fruit yield and quality.

China is a major producer of green tea, and most of its green tea production comes from small farmers. Accessing the carbon emission status of this group can provide data support and a decision-making basis for the realization of carbon neutrality in China’s tea industry. In this study, the life cycle assessment method was used to analyze the carbon footprint of green tea produced by smallholder farmers in Liugou Village, Hanzhong City, Shaanxi Province. The results showed that the carbon emission intensity of green tea for its entire life cycle was 32.90 kg CO2eq kg−1 dry tea, and the carbon emission intensities of its consumption, processing, and cultivation were 14.90, 7.94, and 6.97 kg CO2eq kg−1, respectively. In the processing stage, emissions during steaming and drying accounted for 57%. The use of coal, complicated processing procedures, and older equipment were the main reasons for the high emissions in the processing stage. In the cultivation process, emissions mainly came from fertilizer production and its application in the field. The energy consumption of boiling water resulted in high carbon emissions in the consumption stage. This study suggests that building a scientific fertilization system for tea gardens, optimizing processing equipment and energy utilization structure, and cultivating the concept of low-carbon consumption will be the keys to promoting smallholder farmers to reduce carbon emissions. This study further emphasizes that we should focus on carbon emissions caused by the production processes of small farmers.

Late stage nitrogen (N) applications following basic fertilization are commonly used to ensure grain yield and increase grain protein content in wheat. Split N applications at the late growth stage of wheat are an effective measure to improve N absorption and transport and thus increase grain protein content. However, whether split N applications can alleviate the decrease in grain protein content induced by elevated atmospheric CO2 concentrations (e[CO2]) remains unclear. In the present study, a free-air CO2 enrichment system was used to investigate the effects of split N applications (at booting or anthesis) on grain yield, N utilization, protein content, and the composition of wheat under atmospheric (ACO2; 400 ± 15 ppm) and elevated CO2 concentrations (ECO2; 600 ± 15 ppm). The results showed that wheat grain yield and grain N uptake increased by 5.0% (being grains per ear by 3.0%, 1000-grain weight by 2.0%, and harvest index by 1.6%) and 4.3%, respectively, whereas grain protein content decreased by 2.3% under ECO2 conditions. Although the negative effect of e[CO2] on grain protein content was not alleviated by split N applications, gluten protein content was enhanced due to the alteration of N distribution in different protein fractions (albumins, globulins, gliadins, and glutenins). Compared to that without split N applications, the gluten content of wheat grains increased by 4.2% and 4.5% when late stage N was applied at the booting stage under ACO2 and anthesis under ECO2 conditions, respectively. The results indicate that rational handling of N fertilizers may be a promising approach to coordinating grain yield and quality under the effects of future climate change. However, compared to ACO2 conditions, the key timing for improving grain quality by split N applications should be postponed from the booting stage to anthesis under e[CO2] conditions.

Elevated atmospheric CO2 concentrations (eCO2) has become the main feature and cause of global change that could affect crop growth in many aspects, including physiological processes and morphological development in plants and nutrient cycling and nutrient uptake from the soil. Studying the responses of crop growth to different nitrogen (N) supply forms under elevated atmospheric CO2 concentrations can guide nutrient management strategies for agricultural production under future climate change scenarios. Few studies addressed the effect of eCO2 on N uptake and morphological development for plants. This study was conducted in the CO2-controlled light incubators based on the sand-pot incubation using wheat and maize as experimental plants. Six treatments were set with two different environmental CO2 concentrations (aCO2, 390 µmol mol−1; eCO2, 690 µmol mol−1) and three different N supply forms, including ammonium−N, nitrate−N and ammonium-nitrate with 1:1 ratio. The following results were obtained: (i) Wheat and maize seedlings, as nitrate-preferring crops, grew better under mixed N forms than under single N forms. For the single N supply treatment, seedlings with nitrate−N supply showed better growth than with ammonium. (ii) For wheat plants, seedlings with a single ammonium−N supply showed slender height and fewer tillers; seedlings with a single nitrate−N supply were characterized by slightly shorter plant height, more tillers, and higher aboveground biomass. (iii) Compared to the aCO2 group, wheat seedlings with the ammonium−N supply showed an increased maximum root length and a decreased carbon concentration in root exudates; wheat seedlings with a single nitrate−N supply under eCO2 showed a significant increase in biomass and a decreased carbon concentration in root exudates; wheat seedlings with a mixed N supply under eCO2 explored a significant increase in carbon concentration in root exudate and a relatively lower N concentration. (iv) For maize plants, seedlings with either single ammonium−N or nitrate−N supply did not show significant differences in most growing indices. Maize seedlings with a mixed N supply exhibited an increase in aboveground biomass and N concentration in root exudates compared to those with a single N supply. (v) Compared with the aCO2 group, maize seedlings with mixed N supply under eCO2 conditions exhibited significant increases in plant height, aboveground biomass, and N concentration in root exudates. Single ammonium−N supply was toxic to wheat and maize plants under eCO2 conditions. We recommend raising the ratio of ammonium-to-nitrate under mixed N supply to improve the coordination of carbon and N metabolism for efficient crop growth under climatic change conditions of elevated atmospheric CO2 concentration.

为精准解析中国冬小麦品质的变异特征及其影响因素,利用地理信息系统(GIS)研究中国冬小麦籽粒品质在2006-2019年的时空分布特征,探究影响冬小麦籽粒品质的关键气象因子,分析冬小麦品质与关键气象因子的空间异质性.结果表明,中国冬小麦籽粒蛋白含量、湿面筋含量和沉淀值在空间上总体呈东北高西南低的变化趋势,各指标在时间上没有一致的变化特征.籽粒蛋白含量与开花至成熟期间最高气温大于30℃的天数呈极显著正相关,空间上具有一定正相关特征;湿面筋含量与开花至成熟期的平均气温呈极显著正相关,空间上具有一定正相关特征;沉淀值与开花至成熟期的日照时数呈显著负相关,空间上呈现出明显的负相关.因此,根据影响冬小麦品质形成的关键气象因子,合理布局冬小麦种植区划,制定冬小麦优质发展的气候适宜区,有利于冬小麦品质提升的气候资源高效利用.

This research investigated the N2O fluxes and community compositions of nitrifiers and denitrifiers in a winter wheat-summer maize rotation system on the North China Plain. The experiment included three treatments: 1) a control treatment (CK); 2) biochar at 10.0 t ha(-1) yr(-1) (C); and 3) organic fertilizer at 7.5 t ha(-1) yr(-1) (M). The application of biochar reduced the cumulative N2O emissions by 47.7% and 62.2% in the maize and wheat seasons, respectively, compared with those of the CK treatment. Organic fertilizer increased the cumulative N2O emissions by 311.1% in the maize season and had no significant effects on them in the wheat season. Organic fertilizer reduced the cumulative N2O emissions by 39.8% in the nonfertilizer period of the maize season. The cumulative N2O emissions in the maize season accounted for 75.2-90.0% of the annual emissions among all the treatments. Biochar and organic fertilizer affected soil N2O emissions mainly by changing soil denitrifiers. In the maize season, the lower abundances of Candidatus Nitrosoarchaeum (AOA-amoA), Nitrosomonas (AOB-amoA), Mesorhizobium (nirK), Magnetospirillum (nirS) and Halomonas (nirS) may result in lower N2O emissions in the biochar treatment, and organic fertilizer had a similar influencing mechanism on N2O emissions during the nonbasic fertilizer and nontopdressing periods of the maize season. In the wheat season, the dominant genus Alicycliphilus (nosZ) was the major contributor to decreasing N2O emissions in the biochar treatment, while there was no biomarker related to N2O emissions in the M treatment. The soil pH, NO3--N content and water-filled pore space (WFPS) were the key factors shifting the community compositions of nitrifiers and denitrifiers in this study. The application of biochar could be a better practice to improve saline-alkali soil with lower N2O emissions. These findings will improve our understanding of the nitrifiers and denitrifiers response to biochar and organic fertilizer.

Elucidating the determining factors for wheat quality is an essential but complex task, influenced by wheat cultivars, environmental conditions, and management decisions. This study analyzed 285 winter wheat varieties, 13 wheat quality traits, and 9 influencing factors under a genotype, environment, and crop management framework by a geographical detector model in China’s main winter wheat-producing area. Our results revealed the attribution of wheat quality in the genotype × environment × crop management (G × E × M) interaction framework. The factors influencing wheat quality in China were ranked as follows: wheat cultivar > precipitation > Tmax > irrigation > soil type > Tmin > fertiliser > sunshine duration > landform. The wheat cultivar was the dominant factor affecting wheat quality, which explained 38.57%, 38.78%, and 28.13% of the variation in gluten index, stabilization time, and sedimentation index, respectively. In addition, the sensitivity of the wheat quality traits to the G × E × M interaction framework was detected. The wheat quality trait sensitivity ranked from the highest to the lowest followed the order gluten index > sedimentation index > hardness index > stabilisation time > seed moisture > crude protein > formation time > wet gluten > water absorption > landing value > flour output ratio > ash > capacity. Gluten and sedimentation were highly sensitive traits for wheat quality under the G × E × M interaction framework, with sensitivity index values of 66.94% and 58.11% in the G × E × M framework, respectively. Furthermore, we proposed an integrated improvement strategy for an end-use wheat quality trait based on the sensitivity of wheat quality traits in the G × E × M framework. The gluten index, crude protein, wet gluten, and hardness index should be prioritized according to wheat’s commercial value and sensitivity index. However, other quality traits with higher commercial importance, such as flour output ratio, capacity, and landing value, should be put behind the improvement list. Our result identified the critical factors for most wheat quality traits in the G × E × M framework. It extended the comprehensive strategy for wheat quality improvement.