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The increasing global warming trend has resulted in the mass loss of most glaciers. The Urumqi Vally, located in the dry and cold zone of China, and its widely dispersed glaciers are significant to the regional ecological environment, oasis economic development, and industrial and agricultural production. This is representative of glaciers in Middle Asia and represents one of the world's longest observed time series of glaciers, beginning in 1959. The Urumqi Headwater Glacier No. 1 (UHG-1) has a dominant presence in the World Glacier Monitoring Service (WGMS). This paper supplies a comprehensive analysis of past studies and future modeling of glacier changes in the Urumqi Valley. It has received insufficient attention in the past, and the mass balance of UHG-1 was used to verify that the geodetic results and the OGGM model simulation results are convincing. The main conclusions are: The area of 48.68 ± 4.59 km2 delineated by 150 glaciers in 1958 decreased to 21.61 ± 0.27 km2 delineated by 108 glaciers in 2022, with a reduction of 0.47 ± 0.04 km2·a−1 (0.96% a−1 in 1958–2022). The glacier mass balance by geodesy is −0.69 ± 0.11 m w.e.a−1 in 2000–2022, which is just deviating from the measured result (−0.66 m w.e.a−1), but the geodetic result in this paper can be enough to reflect the glacier changes (−0.65 ± 0.11 m w.e.a−1) of the URB in 2000–2022. The future loss rate of area and volume will undergo a rapid and then decelerating process, with the fastest and slowest inflection points occurring around 2035 and 2070, respectively. High temperatures and large precipitation in summer accelerate glacier loss, and the corresponding lag period of glacier change to climate is about 2–3 years. [ABSTRACT FROM AUTHOR]

Agriculture affects and is affected by climate change. The development of climate-smart agriculture (CSA) is an effective way for agricultural production to cope with climate change. The rice-crayfish coculture system is a combination of the concept of climate-smart agriculture with the experience of traditional Chinese mixed crop-fish systems. This paper reviews the advantages and potential risks of rice-crayfish coculture with respect to climate, ecological environment and economic benefits, and summarises the successful management strategies and operation experiences during the implementation of this CSA practice in Qianjiang City. We also introduce various mixed crop-fish systems in China and suggest the potential of using wetland resources to develop mixed crop-fish systems and CSA. [ABSTRACT FROM AUTHOR]

Agriculture affects and is affected by climate change. The development of climatesmart agriculture (CSA) is an effective way for agricultural production to cope with climate change. The rice-crayfish coculture system is a combination of the concept of climate-smart agriculture with the experience of traditional Chinese mixed crop-fish systems. This paper reviews the advantages and potential risks of rice-crayfish coculture with respect to climate, ecological environment and economic benefits, and summarises the successful management strategies and operation experiences during the implementation of this CSA practice in Qianjiang City. We also introduce various mixed crop-fish systems in China and suggest the potential of using wetland resources to develop mixed crop-fish systems and CSA. [ABSTRACT FROM AUTHOR]

• We calculated carbon sequestration/emissions in agroecosystems in Hebei, China. • We measured agricultural production efficiency considering an undesirable output. • The annual average low-carbon agriculture production efficiency increased by 3.03%. • There were disparities of efficiency among cities owing to increased carbon emission. • Climate change had complex effects on low-carbon agricultural production. With the increase of greenhouse gas (GHG) emissions in the atmosphere, global greenhouse effects have intensified, thereby contributing to climate change. Agriculture contributes to climate change by increasing GHG emissions, and climate change in turn affects agricultural production. In this paper, we calculated carbon emissions and sequestration of agriculture in the 142 counties of Hebei Province, China, and analyzed their spatiotemporal distributions during 2000–2010. Considering net carbon emissions as an undesirable output, we then measured low-carbon agricultural production efficiency using a stochastic directional distance function. We further explored the impacts of climate change on low-carbon agricultural production. We found that carbon emissions in agriculture increased by 15.85% (650 million tons) during 2000–2010, while carbon sequestration in agroecosystems increased by 33.82% (13.8 million tons). The annual average low-carbon agricultural production efficiency increased by 3.03%. There were distinct disparities of efficiency among cities, with the highest efficiency in Chengde and Shijiazhuang. The efficiency in southeastern areas was lower than that in the northwest, owing to the increased carbon emissions. Temperature and precipitation had a positive effect on efficiency in Hebei, whereas extreme weather events caused lower efficiency. The results provide valuable references for developing sustainable, climate-resilient and adaptive agriculture under changing climatic conditions. [ABSTRACT FROM AUTHOR]

Abstract: Irrigation plays an increasing important role in agriculture of China. The assessment of water resources utilization during agricultural production process will contribute to improving agricultural water management practices for the irrigation districts. The water footprint provides a new approach to assessing the agricultural water utilization. The present paper put forward a modified calculation method to quantify the water footprint of crop. On this basis, this paper calculated the water footprint of major crop in Hetao irrigation district, China. Then, it evaluated the influencing factors that caused the variability of crop water footprint during the study period. Results showed that: 1) the annual average water footprint of integrated-crop production in Hetao irrigation district was 3.91m3 kg−1 (90.91% blue water and 9.09% green water). The crop production in the Hetao irrigation district mainly relies on blue water; 2) under the integrated influences of interannual climate variability and variation of agricultural inputs, the water footprint of integrated-crop production displayed a decreasing trend; 3) the contribution rate of the climatic factors to the variation of water footprint was only −6.90%, while the total contribution rate of the agricultural inputs factors was −84.31%. The results suggest that the water footprint of crop mainly depends on agricultural management rather than the regional climate and its variation. The results indicated that the water footprint of a crop could be controlled at a reasonable level by better management of all agricultural inputs and the improvement of water use efficiency in agriculture. [Copyright &y& Elsevier]

The potentially devastating impacts of climate change on crop production and food security are now widely acknowledged. An important component of efforts to mitigate these impacts is the production of new varieties of crops which will be able to thrive in more extreme and changeable environmental conditions. There is therefore an urgent need to find new sources of genetic diversity for crop improvement. Wild plant species closely related to crops (crop wild relatives) contain vital sources of such genes, yet these resources themselves are threatened by the effects of climate change, as well as by a range of other human-induced pressures and socio-economic changes. The flora of China comprises more than 20,000 native higher plant species, a proportion of which have known or potential value as gene donors for crop improvement. However, until now, the full range of these valuable crop wild relative species had not been identified. In this paper we present a methodology for creating a checklist of, and prioritizing China’s crop wild relatives, and reveal that 871 native species are related to crops that are of particularly high socio-economic importance in China—including rice, wheat, soybean, potato, sweet potato, millet and yam—crops which are also of notably high value for food and economic security in other parts of the world. Within this list we have identified species that are in particular need of conservation assessment based on their relative Red List status and potential for use in crop improvement programs. Endemic species that have particularly high economic value potential in China and that are under severe threat of genetic erosion and thus in need of urgent conservation action include wild relatives of tea ( Camellia fangchengensis S. Yun Liang et Y.C. Zhong and C. grandibracteata H.T. Chang et F.L. Yu), apple ( e.g ., Malus honanensis Rehder, M. ombrophila Hand.-Mazz. and M. toringoides (Rehder) Hughes), and pear ( Pyrus pseudopashia T.T. Yu). We provide recommendations for developing a systematic and comprehensive national CWR conservation strategy for China, highlighting the challenges and requirements of taking the strategy forward to the implementation phase. [ABSTRACT FROM AUTHOR]

The yield gap (YG) between the potential yields (Yp) and the average on-farm yields (Ya) is an indicator of the potential improvement for crop production. Understanding how large the current gap is and how this gap has changed over the past few decades is essential for increasing wheat production to meet increased food demand in China. This paper describes a study conducted using an APSIM-Wheat model and farm-level crop yield to analyze the spatio-temporal distribution of the yield gap of winter wheat from 1981 to 2010 in the North China Plain. Nine varieties were calibrated and evaluated based on the data from 16 agro-meteorological experimental sites and then potential yields were estimated considering cultivar replacement. In addition, a trend pattern analysis of on-farm yields for the period 1981-2010 was conducted. Results revealed an estimated yield gap across the entire North China Plain region of 1140-6810 kg ha-1, with a weight average of 3630 kg ha-1 in 1981-2010. Expressed as a relative yield (yield gap % of potential yields), the range was 15-80%, and the weight average was 45%. Despite the negative effects of increasing temperature and decreasing radiation, the potential yields significantly increased by 45 kg ha-1 per year due to cultivar improvement. On-farm yields increased even more notably because of new cultivar selection, increased fertilizer application and other management improvements, but were stagnating in 32.3% of wheat areas, located mainly in Hebei province, Shandong province, Beijing and Tianjin. The improvement of on-farm yields have substantially contributed to yield gap spatio-temporal variation. As a result, the yield gap decreased from 4200 kg ha-1 (56%) in 1981-1990 to 3000 kg ha-1 (35%) in 2001-2010 at a rate of -69 kg ha-1 per year. However, yields stagnation will expand to the northern Henan province without cultivar potential productivity improving, where yield gap was close to or less than 20% of the potential yields and proved difficult to reduce. To further improve the total production of winter wheat in the coming decades, efforts should be paid to break the potential ceiling and reduce the yield gap by breeding higher yield variety and introduction of new agricultural technology. [ABSTRACT FROM AUTHOR]

Abstract: This paper assesses the impact of climate change on China''s agricultural production at a cross-provincial level using the Ricardian approach, incorporating a multilevel model with farm-level group data. The farm-level group data includes 13,379 farm households, across 316 villages, distributed in 31 provinces. The empirical results show that, firstly, the marginal effects and elasticities of net crop revenue per hectare with respect to climate factors indicated that the annual impact of temperature on net crop revenue per hectare was positive, and the effect of increased precipitation was negative when looking at the national totals; secondly, the total impact of simulated climate change scenarios on net crop revenues per hectare at a Chinese national total level, was an increase of between 79 USD per hectare and 207 USD per hectare for the 2050s, and an increase from 140 USD per hectare to 355 USD per hectare for the 2080s. As a result, climate change may create a potential advantage for the development of Chinese agriculture, rather than a risk, especially for agriculture in the provinces of the Northeast, Northwest and North regions. However, the increased precipitation can lead to a loss of net crop revenue per hectare, especially for the provinces of the Southwest, Northwest, North and Northeast regions. [Copyright &y& Elsevier]

In the North China Plain, the grain yield of irrigated wheat-maize cropping system has been steadily increasing in the past decades under a significant warming climate. This paper combined regional and field data with modeling to analyze the changes in the climate in the last 40 years, and to investigate the influence of changes in crop varieties and management options to crop yield. In particular, we examined the impact of a planned adaptation strategy to climate change -'Double-Delay' technology, i.e., delay both the sowing time of wheat and the harvesting time of maize, on both wheat and maize yield. The results show that improved crop varieties and management options not only compensated some negative impact of reduced crop growth period on crop yield due to the increase in temperature, they have contributed significantly to crop yield increase. The increase in temperature before over-wintering stage enabled late sowing of winter wheat and late harvesting of maize, leading to overall 4-6% increase in total grain yield of the wheat-maize system. Increased use of farming machines and minimum tillage technology also shortened the time for field preparation from harvest time of summer maize to sowing time of winter wheat, which facilitated the later harvest of summer maize. [ABSTRACT FROM AUTHOR]

Abstract: China is one of the most important rice production countries in the world, and maintaining high rice productivity in China is very important for world food security. While previous studies showed that rice production in China has been and will be negatively impacted by global warming, the confounding effects of climatic change, variety improvement and agronomic managements have not been separately investigated. In this paper we combine an analysis of climate and rice growth data with crop modeling to investigate the impact of changes in climate, rice varieties, and agronomic management on rice productivity at four sites (Wuchang, Xinyang, Zhenjiang and Hanyuan) in China. The results showed a significant increase in minimum temperature during all rice growth stages at Wuchang and Zhenjiang, and from heading to maturity at Xinyang, but little change at Hanyuan. Global warming would have led to a reduction in the length of rice growing period and a reduction in grain yield at all study sites, if no varietal changes had occurred. However, the adoption of new rice varieties stabilized growing duration, increased harvest index and grain yield at three of the four sites. In the face of future warming, a planned breeding effort may be needed to offset the negative impact of future climate change. [Copyright &y& Elsevier]

Abstract: Characterizing the carbon footprint (CF) of agricultural production offers key information for pursuing low carbon agriculture and food consumption. While China has long strived for increasing food production capacity for its large and still growing population, the high emissions cost, especially from the over use of agro-chemicals, has been widely debated for the last decade. However, the CF of China''s crop production has not yet been assessed. This paper reports a basic estimate of CF of crop production using national statistical data available for the period of 1993–2007. The dataset includes the amount of individual agricultural inputs (fertilizer, pesticide, diesel, plastic film, etc.), cultivation area and total of production whole crops. Using the emission factors estimated for China''s agricultural features and available abroad, the mean overall CF of China''s crop production was estimated to be 0.78±0.08tCEha−1 yr−1 and 0.11±0.01tCEt−1 yr−1, for land use and bulk production respectively. For the duration the data covered, the carbon intensity under cultivation land use was seen to increase since 1993. Among the total, fertilizer induced emissions exerted the largest contribution of ∼60%, being 0.45±0.04tCE per ha and 0.07±0.01tCE per ton of production, on average. Compared to the UK, the estimated overall CF of China''s crop production was higher in terms of cultivation land use. While there was a significant positive correlation of carbon intensity with total production, carbon efficiency was shown in a decreasing trend during 2003-2007. Therefore, low carbon agriculture should be pursued, and the priority should be given to reducing fertilizer application in agriculture of China. However, for developing best management practices for climate change mitigation in crop production of China, further studies of crop and regional specific CFs and the variation with climate conditions and agricultural managements are needed. [Copyright &y& Elsevier]

This paper presents an agent-based simulation (ABS) and cellular automata (CA) coupled model to simulate the spatial evolution of the population of China over the past 2000 years. In the model, agents are used to simulate individuals who live in a geographic environment represented by the CA. The choice to migrate is influenced by climate change, potential agricultural productivity change, and waves of mass migrations. Using the simulation, we can observe the spatial evolution of the population, as well as the shift of the population center of gravity, and we can analyze the driving forces of these changing spatial patterns. [ABSTRACT FROM AUTHOR]

The North China Plain (NCP) is the most important agricultural production area in China. Crop production in the NCP is sensitive to changes in both climate and management practices. While previous studies showed a negative impact of climatic change on crop yield since 1980s, the confounding effects of climatic and agronomic factors have not been separately investigated. This paper used 25 years of crop data from three locations (Nanyang, Zhengzhou and Luancheng) across the NCP, together with daily weather data and crop modeling, to analyse the contribution of changes in climatic and agronomic factors to changes in grain yields of wheat and maize. The results showed that the changes in climate were not uniform across the NCP and during different crop growth stages. Warming mainly occurred during the vegetative (preflowering) growth stage of wheat and maize, while there was a cooling trend or no significant change in temperatures during the postflowering stage of wheat (spring) or maize (autumn). If varietal effects were excluded, warming during vegetative stages would lead to a reduction in the length of the growing period for both crops, generally leading to a negative impact on crop production. However, autonomous adoption of new crop varieties in the NCP was able to compensate the negative impact of climatic change. For both wheat and maize, the varietal changes helped stabilize the length of preflowering period against the shortening effect of warming and, together with the slightly reduced temperature in the postflowering period, extend the length of the grain-filling period. The combined effect led to increased wheat yield at Zhengzhou and Luancheng; increased maize yield at Nanyang and Luancheng; stabilized wheat yield at Nanyang, and a slight reduction in maize yield at Zhengzhou, compared with the yield change caused entirely by climatic change. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the study on agriculture adaptation to climate change by adopting the assumed land use change strategy to resist the water shortage and to build the capacity to adapt the expected climate change in the northern China. The cost-benefit analysis result shows that assumed land use change from high water consuming rice cultivation to other crops is very effective. Over 7 billions m[sup 3] of water can be saved. Potential conflicts between different social interest groups, different regions, demand and supply, and present and future interests have been analyzed for to form a policy to implement the adaptation strategy. Trade, usually taken as one of adaptation strategies, was suggested as a policy option for to support land use change, which not only meets the consumption demand, but also, in terms of resources, imports water resources. [ABSTRACT FROM AUTHOR]

Spatio-temporal variations in precipitation are affecting agricultural production in China in the context of climate change. Based on daily precipitation data from 63 national meteorological stations on the Huang-Huai-Hai Plain from 1963 to 2012, this paper analysed the spatio-temporal variations in precipitation in terms of precipitation days and intensity, using spatial interpolation, linear trend estimation and wavelet analysis. The results indicated that: (i) from 1963 to 2012, the number of annual precipitation days and intensity decreased gradually from the southeast to the northwest. Additionally, the distribution of the extreme precipitation index was similar to that of the annual precipitation index; (ii) the number of annual precipitation days and heavy precipitation days gradually decreased, while precipitation intensity and extreme precipitation days and extreme rainfall intensity remained relatively stable or decreased. The spatial patterns of annual variation trends were considerably different. The annual precipitation days and intensity trends are consistent with the overall trend, while that of the extreme rainfall index in some regions differs from the overall trend; (iii) the precipitation index displayed different periodic oscillations during the period, and the precipitation index values differed at different time scales. However, all the precipitation index values exhibited a 28-yr oscillation. [ABSTRACT FROM AUTHOR]