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Background: The study was conducted to investigate the short‐term complications and prognostic factors in patients with esophagogastric junction adenocarcinoma (EGJA). Methods: This retrospective study included 110 EGJA patients who underwent surgery from January 2010 to November 2012 at The First Affiliated Hospital of BengBu Medical College. The overall survival and short‐term complications were analyzed according to the patients’ clinical characteristics. Results: The incidence of postoperative cardiopulmonary complications was significantly higher in patients with preoperative cardiopulmonary disease or elderly patients (P < 0.05). Four cases of upper margin cancer residue were detected using the abdominal approach and three using the thoracic approach, which indicated that the cancer residue margin was related to surgical approach. The overall five‐year survival rate was 34.3% and statistically differed according to pathological stage and en block resection (Pall < 0.05). Cox regression analysis showed that lymph node metastasis (P < 0.05) and the extent of tumor invasion (P < 0.05) were independent prognostic factors. Conclusion: Elderly patients with preoperative cardiopulmonary disease had an increased risk of developing postoperative cardiopulmonary complications. Lymph node status and depth of tumor invasion were independent factors related to patient prognosis. [ABSTRACT FROM AUTHOR]

Abstract: Appropriate fertilization practices play a critical role in enhancing crop yields, as well as in achieving sustainable increases in crop production through improving soil quality. In the present study, we examined the effects of long-term fertilization (started in 1986) on crop yield and its sustainability under a double corn (Zea mays L.) cropping system in an Ultisol of southern China. Results showed that although corn yields were higher in the fertilized treatments compared to the unfertilized control, inorganic fertilizer application alone (N and NPK) resulted in declining trends in both corn yields and fertilization effects (defined as the yield difference between the fertilized treatment and the control), especially in the N treatment. In contrast, significant increasing trends in both corn yields and fertilization effects were observed in the manure-applied treatments. Manure amendments significantly increased the contents of soil organic carbon and total N and the availability of soil P and K, while long-term inorganic fertilization alone accelerated soil acidification, especially in the N treatment. In addition, there was no significant correlation between the yield trend and climatic factors (weather trends) over the period of study. Thus, it is likely that the long-term sustainability of corn production under manure application is attributed mainly to the improved soil quality. Our results also suggest that manure amendments, particularly in combination with inorganic NPK, should be the recommended fertilization practice to enhance corn yields and improve soil quality in the Ultisol. [Copyright &y& Elsevier]

Abstract: Increasing evidence has shown that recommended management practices (RMPs) benefit carbon sequestration in cropland soils, but the differences in the effect size and duration between RMPs are not well documented, especially in paddy fields where multiple cropping systems are in use. In order to select feasible techniques and develop effective strategies for soil organic carbon (SOC) management for long-term sustainable rice production that promote environmental health, we conducted a meta-analysis to compare the carbon sequestration effects based on size and duration of several common RMPs using in the Yangtze Delta Plain of eastern China. The meta-analysis data base included 26 long-term field experiments with 86 paired trials. The mean depth of soil sampling in all trials was 16.5cm. Results showed that there were significant effects from applications of crop residue and animal manure applications on levels of carbon sequestration. Crop residue additions and animal manure applications increased SOC by 0.41Mgha−1 yr−1 and 0.34Mgha−1 yr−1 on average during the experiment period, respectively. In contrast, reduced/no tillage practices had no effect on levels of carbon sequestration in the study area. Crop residue additions and animal manure applications will enhance SOC, but only over periods of about 20 and 40 years, respectively. Significantly greater effect of RMPs on carbon sequestration occurred in a triple cropping system incorporating with double rice than that in double cropping system with only a single rice season. The above results suggest that increases in organic matter, such as additions of crop residues and animal manure to soils may have great effects on carbon sequestration in paddy fields in the research area. [Copyright &y& Elsevier]

Straw incorporation promotes rice productivity and soil fertility. However, the effects of tillage practice with straw on GHG emissions in paddy fields are not well documented. Under three rice-based cropping systems of China (single rice, double rice and rice-wheat cropping systems), we investigated rice yield, CH4, N2O, area and yield-scaled emissions arising from different straw-incorporated tillage patterns. Tillage with straw affected rice yield by −6.8~3.2%, −9.1~9.0% and −9.8~2.1% in single rice, rice-wheat and double rice cropping systems respectively. Straw impacted CH4 emission but tillage influenced its impact irrespective of the rice cropping system. The highest CH4 emissions occurred in RedT + S, RoT + S and RoT + S under single rice, rice-wheat and double rice cropping systems respectively. Cumulative CH4 emission of PT + S decreased by 46.8% (p < 0.05) compared to RedT + S in the single cropping system, while under rice-wheat and double rice cropping systems, cumulative CH4 emission of PT + S decreased by 19.0% (p < 0.05) and 13.2% (p > 0.05) respectively compared with RoT + S. Lower methanogenic abundance of PT + S translated into the lowest cumulative CH4, area and yield scaled emissions in single rice and double rice cropping systems. To maintain high rice yield and reduce GHG emissions from straw incorporation, PT + S is recommended for a rice-based cropping system. [ABSTRACT FROM AUTHOR]

Rice paddies supply the staple food for 50% global population, but contribute 48% of greenhouse gas (GHG) emissions from croplands. Temperature is the key factor of rice yield and GHG emissions, but warming effects (i.e. elevated temperature ≤ 2°C) are still unclear, especially in hotspots. Therefore, we collected the global in-situ observations of warming experiments and corresponding environmental factors to identify the key drivers of warming effects, and developed the statistic models to assess the effects of warming on GHG emissions from China's rice paddies. Our results indicate that the variation in warming effects on rice yield, methane (CH 4) emissions, and nitrous oxide (N 2 O) emissions are primarily explained by ambient temperature of post-anthesis, ambient temperature of flooding stage, and soil pH, respectively. Considering these key factors, we estimate that warming does not significantly affect China's total rice yield, while can increase CH 4 emissions by 13.6% °C−1, N 2 O emissions by 30.5% °C−1, and area-/yield-scaled GHG emissions by 14.9% °C−1 from China's rice paddies. Warming reduces rice yield but increases GHG emissions more strongly in East, South and Central China, compared to North, Northwest, Northeast, and Southwest China. Our findings quantify the warming effects on rice yield and GHG emissions, and provide new perspectives for the hotpots of warming effects on China's rice production. In the warmer future, we still need more efforts on smart adaptation strategies to maintain rice yield and curb GHG emissions from rice agriculture. • Temperature and soil pH can explain variation in warming effect on GHG emissions. • Warming effect on N 2 O emissions shows a negative relationship with soil pH. • Warming does not affect China's total rice yield while increases GHG emissions. • Warming increases yield-scaled GHG emissions by 14.9% °C−1 in China's paddies. • East, South and Central China's rice paddies are the hotspots of warming effects. [ABSTRACT FROM AUTHOR]

Including green manure into a rice-based double-cropping system has effects on both crop production and greenhouse gas (GHG) emissions. Yet, few studies have considered the trade-off between crop productivity, profitability, and carbon footprint (CF) in this cropping system of China. Thus, the impacts of different cropping regimes on crop productivity, economic benefits, carbon footprint, and net ecosystem economic budget (NEEB) were investigated. The treatments were rice–wheat (R–W), rice–rape (R–R), rice–hairy vetch (R–H), rice–barley (R–B), rice–faba bean (R–F), and rice–fallow (R). Compared to R–W treatment, planting rape (R–R), green manure (R–F, R–H), or fallow (R) in winter season tended to improve rice yield, but they were not conducive to yield stability. Treatments of R–H, R–F, and R reduced both direct and indirect GHG emission, and thus mitigated the area-scaled carbon footprint by 34.4%, 44.2%, and 49.7%, respectively, compared to R–W treatment. The economic benefits under R–R, R–B, or R system were not different from those of R–W treatment, while R–H reduced the economic benefit by 70.1%. In comparison with R–W treatment, R–H treatment reduced the NEEB, while R–F significantly increased the NEEB by USD 4065 ha−1. The present results indicate that as a measure to realize the combination of food security and environmental cost reduction, substituting leguminous crops with wheat can mitigate carbon emissions while ensuring profitability, on the premise of yield stability. [ABSTRACT FROM AUTHOR]

Great uncertainties remain in the impact of cropping systems on soil organic carbon (SOC) stocks in paddy fields that hold a large potential for carbon (C) sequestration. In this study, a meta-analysis was performed to examine trends on SOC stocks in unfertilized and fertilized fields from three of the most common rice cropping systems in China. Results showed that rice cropping without any nutrient application (Control) significantly increased SOC stocks by 9% compared to the initial level in double rice cropping systems (DR), whereas no significant effects were observed in single rice cropping systems (SR) and rice-upland crop rotation systems (RU). Paddy soils sequestered C in all the three cropping systems under inorganic NPK fertilization, and the magnitude of the increase in SOC stocks was in the order DR > RU > SR. Soil C stocks increased with the increasing cropping duration. Continuous rice cropping for more than 20 years led to average SOC gains of 15% and 23% in the control and NPK treatments, respectively. Furthermore, it seems that C sequestration was still occurring in the longest fields from the included studies. Thus, no SOC saturation trend was found over the investigated cropping duration. However, the negative relationship between SOC changes and their initial C stocks suggests indirectly the possibility of SOC saturation in paddy fields. [ABSTRACT FROM AUTHOR]

Global agriculture is facing multiple challenges to meet the food demands, optimize resource utilization, and mitigate the climate change. A field study, combined with the life cycle assessment (LCA), was conducted to select the effective and sustainable cropping systems in northwestern China. The study compared four maize‐based intercropping and corresponding monoculture systems on crop yield, evapotranspiration (ET), water use efficiency (WUE), profitability, and carbon footprint (CF). Maize/wheat intercropping had the highest energy yield (532.5 GJ/ha, on average) and maize equivalent energy yield (MEEY) (522.3 G/ha, on average), followed by those from the maize/rape intercropping system, and the lowest by the sole potato system. The WUE of maize equivalent energy yield (WUEMEEY) was the highest (1.06 GJ ha−1 mm−1) for sole rape system, followed by those for the maize/wheat and maize/rape intercropping systems. Maize/potato intercropping had the highest benefit: cost ratio at 3.30, followed by those for the maize/wheat intercropping (2.58), sole potato (2.57), and maize/rape intercropping (2.53). Lower CF and higher net ecosystem economic budget (NEEB) were observed in maize‐based intercropping systems. The maize/wheat intercropping system had the lowest CF per maize equivalent energy yield (CFm) (10.7 kg CO2‐eq GJ−1 year−1), and the maize/potato intercropping system had the lowest CF per unit economic output (CFe) (0.14 kg CO2‐eq US$−1 year−1), and the highest NEEB (7,352.8 US$/ha). The data presented indicate that maize‐based intercropping system may be a viable practice for the synthesized goals of higher productivity and profitability while lesser environmental footprint in a water‐scarce region of northwest China. [ABSTRACT FROM AUTHOR]

A long-term field experiment was performed to assess the effects of fertilization regimes on greenhouse gas emissions, soil properties, soil denitrifies, and maize (Zea mays) grain yield on Mollisols of Northeastern China. Chemical nitrogen (N), phosphorus (P), and potassium (K) fertilizers plus pig manure (MNPK) treatment significantly increased soil N2O emissions by 29.9–226.4% and global warming potential (GWP) by 29.8–230.7% compared to unfertilized control (CK), chemical N fertilizer only (N), chemical N, P, and K fertilizers (NPK) and chemical N, P, and K fertilizers plus corn straw (SNPK) treatments. However, the MNPK treatment yielded similar greenhouse gas intensity (GHGI) as compared with other treatments, mainly due to higher maize grain yield. There were also higher gene copy numbers of nirK, nirS, and nosZ in topsoil (0–20 cm depth) under MNPK treatment. Automatic linear modeling analysis indicated that main factors influencing soil N2O emissions were soil organic carbon (SOC), NO3− content, and nirK gene abundance. Although the application of chemical fertilizers plus organic manure increases N2O emissions due to higher N and C availability and nirK gene activity in the soil, this is still a promising fertilizer management due to its notable enhancement of maize grain yield and SOC content. [ABSTRACT FROM AUTHOR]

Maize production is facing multiple challenges toward increasing crop productivity, enhancing resource utilization, and mitigating climate change nowadays. Climate-smart agriculture (CSA) is an emerging concept, which pursues the synthesis of higher crop productivity, lower carbon emissions, and improved soil resilience to the climate change. However, few studies have been done to evaluate the productivity and environmental consequences following the CSA of maize production. Herein, the effects of CSA practice on maize yield, nitrogen use efficiency (partial factor productivity, PFP N), soil organic carbon (SOC) sequestration, and carbon footprint (CF) were evaluated based on a nine-year in-situ field experiment in northeastern China. The experiment followed a randomized block design with three treatments including in traditional farmers' practices (FM), optimized agronomic practices (OPT, aiming to high grain yield and PFP N), and climate-smart agriculture practices (CSA, aiming to higher grain yield, PFP N , SOC stock, while lower CF). Compared with FM, OPT and CSA practices significantly increased grain yield and PFP N by 25.0%− 30.1% and 92.2%− 100.2% on average of experimental duration, respectively. CSA practice had significant higher global warming potential (GWP) but equivalent global warming potential intensity (GWPI) than these of FM and OPT practices during 2016 and 2017. Meanwhile, CSA practice also achieved the highest SOC sequestration in 0–40 cm soil depth compared to other treatments. Consequently, CF per hectare (CF a) of CSA significantly decreased by 41.4% on average than that of FM mainly due to higher SOC sequestration. Concerning the profit of cropping system, CSA had the highest net ecosystem economic budget (NEEB) of 2090.62 $ ha−1 among the treatments. Overall, CSA practice showed advantages in promoting maize yield while reducing carbon footprint by integrated agronomic management (e.g. dense planting, subsoiling tillage, manure amendments, nitrogen fertilizer optimization, and so on), which could be regarded as a promising practice towards food security and carbon emission mitigation. [Display omitted] • An integrated agronomic practice was setup aiming to climate-smart agriculture (CSA). • CSA practice increased maize yield and nitrogen use efficiency compared to business as usual management. • CSA practice reduced carbon footprint by enhancing soil organic carbon stock and reducing indirect greenhouse gas emission. • It was demonstrated that CSA practice achieves the synergy of sustainable maize productivity and lower environmental costs. [ABSTRACT FROM AUTHOR]

Fertilizer application often significantly affects soil quality and crop productivity, thus, can affect soil greenhouse gas (GHG) emissions and nitrogen use efficiency (NUE) as well. However, the impacts have not been well documented under double maize cropping system in subtropical China. Based on a thirty-year field experiment with five fertilization treatments (i.e. no fertilizer (CK), organic manure (OM), N, NPK and NPK plus OM (NPKM)), maize cultivar (Yedan 13) was planted both at the early maize season and late maize season, we assessed the impacts of different fertilizer application on nitrous oxide (N 2 O) and methane (CH 4 ) emissions, grain yield and NUE. Compared to the NPK, manure application (i.e. OM and NPKM) significantly increased N 2 O emissions, and maize yield. Nevertheless, there was no significant difference in yield–scaled global warming potential (GWP) among NPK, OM, and NPKM. Manure application increased soil pH, soil organic carbon, and soil total N, suggesting it can improve soil quality. The NPKM treatment had the highest N uptake, but in terms of NUE, it was lower than OM, due to double N application. Our results suggest that manure application can compensate its negative impacts on N 2 O emission through improving soil quality, maize yield and N use efficiency. [ABSTRACT FROM AUTHOR]

Improving soil aeration in paddy fields using mechanical device reduces methane (CH 4) emissions, whereas it also increases the contribution of other sources (device production, agricultural inputs, etc.). Here, this study applied the life cycle assessment (LCA) method to evaluate the carbon footprint of a soil air injection device (SAID) in rice field. We further analyzed the prospects of this device in promoting carbon emission reduction in China's main rice-producing areas, which was combined with economic benefit calculation and revised knowledge-attitude-practice (KAP) model. Results showed that the reduction of net carbon emissions from paddy fields under SAID treatment was 4.51–241.95% higher than the total carbon emissions from the production, transportation, operation, and recycling of SAID. The economic output of using SAID in rice fields could just offset the cost of it. With reasonable government subsidies (142.80–349.95 yuan SAID−1 yr−1), SAID can reduce carbon emissions from Chinese rice fields by ∼ 41.60 Tg CO 2 -eq yr−1. This study suggests that using SAID in some rice planting areas in China may be an effective way to reduce carbon emissions. [Display omitted] • SAID could reduce carbon footprint of rice production system. • The limiting factor for the development of SAID is mainly low economic efficiency. • The cost of emission reduction in each region is 0.16–6.07 yuan per kg CO 2 -eq. [ABSTRACT FROM AUTHOR]

China is the largest country in grain production and consumption with the greatest emission of greenhouse gas (GHG) in the world. To learn the historical changes and regional differences in GHG emission of the major grain crop production can provide important references to the mitigation of GHG emission in the country and other similar countries. Therefore, we quantified the carbon footprints of rice ( Oryza sativa L.), wheat ( Triticumaestivum L.) and maize ( Zea mays L.) production based on agricultural inputs in the country over the period of 1978–2012. The results showed that area-scaled carbon footprint of rice, wheat and maize production increased gradually from 1286, 937 and 895 kg carbon dioxide equivalent (CO 2 -eq) ha −1 in 1978–2682, 2978 and 2294 kg CO 2 -eq ha −1 in 2012, respectively, and the average increase rates for the three crops were correspondingly 41, 60 and 41 kg CO 2 -eq ha −1 a −1 . During the last ten years, however, all the average yield-scaled carbon footprints of rice, wheat and maize decreased by 0.11 kg CO 2 -eq kg −1 10a −1 . Chemical fertilizer contributed the largest ratio to the total GHG emission by 66, 68 and 76% for rice, wheat and maize, respectively. Significant increasing contribution ratio to the carbon footprint was found in the electricity used for crop irrigation. There were large differences in both the area- and yield-scaled carbon footprints among the cropping regions with the lowest GHG emission occurring in the major cropping regions. Our findings indicate a great potential to reduce GHG emission of grain production through optimizing the spatial layout of cropping region and enhancing chemical fertilizer use efficiency. Further efforts also need to be made on water-saving irrigation to decrease the electricity usage. [ABSTRACT FROM AUTHOR]

Aims: The stability of soil organic carbon (SOC) is of great importance in controlling long-term carbon (C) sequestration and feedbacks of soil C pools to climate change. It has been well documented that rice cropping and organic amendments could enhance SOC stocks, while the stability of the sequestered C has not been well understood yet. The objective of this study was to examine the difference in SOC content and stability between a paddy and an upland field under long-term fertilization and to explore the potential link between SOC chemical and biological stability. Methods: Soils were collected from two adjacent long-term paddy (annually double-rice cropping) and upland (annually double-corn cropping) experiments with the same soil parent material, where different fertilization regimes were initiated in 1981 and 1986, respectively. The chemical and biological stability of SOC were measured by acid hydrolysis and aerobic incubations, respectively. Results: The C concentration was significantly higher in the paddy soil than in the upland soil, regardless of fertilization regimes. As compared to the initial level, long-term rice cropping without any fertilization (CK) significantly enhanced SOC concentration, whereas corn cropping led to a slight decline. Manure amendments combined with inorganic NPK fertilizers (NPKM) significantly increased SOC content relative to the inorganic NPK application alone treatment (NPK) in both the upland and paddy fields. The paddy soil had significantly greater cumulative C released per gram of soil C (i.e., the biological stability of SOC) than the upland soil. Cumulative C released per gram of soil C was significantly higher in NPKM than in NPK in both the paddy and upland soils, whereas no significant difference was observed between the CK and NPK treatments. Acid hydrolysis could reveal the difference in C stability between the paddy and upland soils, but could not characterize the effect of fertilization. Conclusions: Rice cropping facilitates SOC accumulation relative to upland cropping, whereas the inherent SOC stability is lower under the former than the latter in the site. The lower SOC turnover in the paddy than in the upland is mainly due to anaerobic conditions. Organic amendments significantly enhance SOC, but reduce its stability in both the paddy and upland fields. The sensitivity of acid hydrolysis is relatively low in determining SOC stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • What and how land-use change affects soil respiration in Qinghai-Tibetan Plateau. • Field monitoring with five land-uses in an alpine agro-pastoral ecotone. • Enclosed grassland had the highest soil respiration while the lowest in abandonment. • Quantified causal pathways from land-use change to variations in soil respiration. • Grasslands benefits for both low soil respiration and high soil C storage. Land-use change alters soil carbon (C) storage in terrestrial ecosystem through affecting soil respirations (Rs). However, the long-term effects of land-use change on Rs are poorly understood. We undertook a field experiment to examine the effects of long-term land-use change on Rs. The land-use types included grazed grassland (GGL), enclosed grassland (EGL), continuous cropland (CCL), rotation cropland (RCL) and abandoned cropland (ACL) in an alpine agro-pastoral ecotone in Qinghai-Tibetan Plateau in China. Our results showed that the accumulative Rs was shown a decreasing order of EGL > CCL > RCL > GGL > ACL, with the highest value of 12.2 t CO 2 ha−1 and the lowest value of 5.3 t CO 2 ha−1. Soil bulk density, moisture, pH and C/N ratio were the key factors regulating Rs with land-use change in Tianzhu alpine agro-pastoral ecotone. Soil pH and C/N ratio regulated Rs indirectly by affecting bacterial diversity, while soil moisture had indirect impacts on Rs mainly by regulating microbial biomass. The net effects of soil bulk density on Rs was mainly through the direct pathway. Considering the soil C stocks showed an increasing order of ACL < RCL < CCL < GGL < EGL, even though ACL had the lowest Rs , grasslands probably the favorable land-use type in alpine agro-pastoral ecotone. Our findings highlight the importance of the land-use change on Rs , which may need to be incorporated into regional and global models for better predicting C-climate feedbacks. [ABSTRACT FROM AUTHOR]

Mechanical planting is replacing manual transplanting in the major Asian rice cropping areas, however, few are known about the impacts of mechanical planting on rice yield and greenhouse gas (GHG) emission. Therefore, a two-year experiment was conducted to examine the impacts of dry direct-seeding (MDS), wet direct-seeding (MWS) and transplanting (MTP) in Jianghuai area, China. The results showed that CH 4 emission was significantly lower in the MDS than the MWS and MTP both with and without straw incorporation. No significant difference in N 2 O emission was found among the planting methods. Straw incorporation significantly stimulated CH 4 emission in the MWS and MTP, but not in the MDS. The lowest rice yield was found in the MWS, while there was no significant difference in grain yield between the MDS and MTP methods. The area-scaled emission of CH 4 and N 2 O in CO 2 -equivalent unit was respectively 78.5 and 89.6% lower in the MDS than those in the MWS and MTP without straw incorporation, and 87.7 and 94.1% lower with straw incorporation. The yield-scaled emission was correspondingly 80.4 and 88.1% lower without straw incorporation, and 89.0 and 93.4% lower with straw incorporation, respectively. Our results indicate that MDS can get an acceptable yield with a large reduction in GHGs emissions in the test location. [ABSTRACT FROM AUTHOR]

Climatic warming is often predicted to reduce wheat yield and grain quality in China. However, direct evidence is still lacking. We conducted a three-year experiment with a Free Air Temperature Increase (FATI) facility to examine the responses of winter wheat growth and plant N accumulation to a moderate temperature increase of 1.5°C predicted to prevail by 2050 in East China. Three warming treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming) were applied for an entire growth period. Consistent warming effects on wheat plant were recorded across the experimental years. An increase of ca. 1.5°C in daily, daytime and nighttime mean temperatures shortened the length of pre-anthesis period averagely by 12.7, 8.3 and 10.7 d (P<0.05), respectively, but had no significant impact on the length of the post-anthesis period. Warming did not significantly alter the aboveground biomass production, but the grain yield was 16.3, 18.1 and 19.6% (P<0.05) higher in the AW, DW and NW plots than the non-warmed plot, respectively. Warming also significantly increased plant N uptake and total biomass N accumulation. However, warming significantly reduced grain N concentrations while increased N concentrations in the leaves and stems. Together, our results demonstrate differential impacts of warming on the depositions of grain starch and protein, highlighting the needs to further understand the mechanisms that underlie warming impacts on plant C and N metabolism in wheat. [ABSTRACT FROM AUTHOR]

Highlights: [•] Corn yield is affected by climate patterns in cool-high latitude rainfed area. [•] Flat planting increases topsoil water storage and minimum temperature at early stage. [•] Ridge planting can reduce waterlogging risk at middle and later growth stages. [•] Flat planting with ridge at V6 stage achieves higher corn yield due to improved soil moisture and temperature conditions. [Copyright &y& Elsevier]

Increasing crop biodiversity often increases agro-ecosystem services, however, the effects of crop biodiversity on crop yield and environmental benefits are still unclear. Thus, we conducted a 4-yr field experiment in northeastern China including continuous maize (CM), continuous soybean (CS), maize and soybean rotation (M-S), and maize and soybean intercropping (M/S) to evaluate the crop productivity, economic returns, carbon footprint (CF) and carbon sustainability index (CSI) among the cropping system regimes. Compared with CM treatment, M-S and M/S achieved lower energy yield (EY) and maize equivalent economic yield (MEEY), but higher economic returns. The mean annual net revenue of M-S treatment was 7.2% higher, and the mean annual benefit: cost ratio of M-S and M/S treatments were 12.0% and 8.8% higher than those of CM treatment. Based on the life cycle assessment (LCA), lower CFs were observed in the M-S and M/S systems. The CF per unit of area (CF A) of M-S and M/S treatments was 21.4% and 51.3% lower than that of the CM treatment, respectively. The CF per kg of energy yield (CF EY) of M/S treatment was 35.4% lower, compared with that of the CM treatment. The CF per kg of maize equivalent economic yield (CF MEEY) under M/S treatment was 44.0% lower, than that of the CM treatment. Moreover, CF per unit of economic output (CF E) of M/S treatment was 45.0% lower than that of the CM treatment. The highest CSI was observed in M-S treatment, and it was 61.4% higher than that of CM treatment. Our findings indicate that diversified crop practice (e.g. maize-soybean intercropping and rotation systems) could achieve lesser carbon footprint and higher profitability, however, might compromise grain or energy yield. [Display omitted] • The productivity, profitability, and environmental costs of different cropping systems were evaluated. • Diversified crop practice had lesser carbon footprint and higher profitability. • Maize-soybean intercropping systems is an alternative to the traditional maize monoculture system in northeastern China. [ABSTRACT FROM AUTHOR]

Abstract: Recently increasing studies suggest that a comprehensive assessment of cropping practices impacts on greenhouse gas (GHG) emissions at yield-scale will benefit cropping technique innovation and policy selection for higher-yield with less-emissions. In this paper, we conducted a meta-analysis to quantify the impacts of rice cropping practices on the global warming potential (GWP) of GHG emissions at yield-scale rather than area-scale in China. The results showed that the yield-scaled GWP of Chinese major rice cropping systems during rice growing season was in the order: double rice cropping system (1188.9kg CO2 equiv.Mg−1)>rice-upland crop rotation system (777.0kg CO2 equiv.Mg−1)>single rice cropping system (346.7kg CO2 equiv.Mg−1). Nitrogen fertilization (50–300kgNha−1) significantly increased rice yield with slight increments in the GWP of CH4 and N2O emissions, resulting in significant reductions in the yield-scaled GWP. The greatest reduction occurred at the application rate of 150–200kgNha−1 by 37% as compared to the non-fertilization control. For organic amendments, biogas residue application had no significant effect on the yield-scaled GWP, while manure application and straw recycling significantly increased the yield-scaled GWP by 54% and 154%, respectively. Intermittent irrigation significantly reduced yield-scaled GWP by 59% largely because of a significant reduction in CH4 emission and a significant increment in rice yield. No-tillage showed lower CH4 emission with similar rice yield in comparison with the conventional tillage, resulting in a reduction in yield-scaled GWP by 20%. These results indicate that there is a great potential to meet the new objective of higher-yield with less-GHG emissions through innovating rice cropping technique. More efforts should be paid on the field observations of GHG emissions during non-rice growing season, so as to perform a life-cycling assessment of GHG emissions from rice fields at yield scale under different cropping systems. [Copyright &y& Elsevier]

Abstract: A five-year experiment with Free Air Temperature Increase facility was conducted to investigate the actual responses of winter wheat phenophase and yield to warming in Yangtze Delta Plain, China. Air temperature increase of around 1.5°C in wheat canopy advanced crop phenophases significantly, leading to a reduction in length of the entire growth period by 10 days (P <0.05). This reduction was mainly found in the length of pre-anthesis phase, while the length of post-anthesis phase was prolonged slightly. Warming increased grain yield by 16.3% (P <0.05) whereas no significant effects were found on the aboveground biomass. Warming tended to increase the numbers of productive spike and filled grain and the harvest index. The areas of flag leaf and total green leaf at anthesis and the 1000-grain weight were 36.0, 19.2 and 5.9% higher in the warmed plots than the un-warmed control (P <0.05), respectively. Warming stimulated the filling rate of inferior grain (P <0.05), while the rate of superior grain stayed almost unchanged. The above evidences suggest that anticipated warming may facilitate winter wheat production in East China. [Copyright &y& Elsevier]

Abstract: To learn the historical response of cropping system to climate change will benefit the strategy decision of future cropping adaptation. In this paper, we conducted an integrated analysis of the climate records of seventy-two meteorological stations and the records of crop yields over the period 1970–2009 in Northeast China. It was found that over these forty years, the daily mean, maximum and minimum temperatures during crop growing season increased on average by 0.34°C, 0.28°C, 0.43°C every ten years, respectively. No significant change in the precipitation was found, although the differences between years were large. After de-trending the agronomic technique contributions to the increments of crop yields, the historical warming had led to great annually increments of 16.6kgha−1, 15.5kgha−1 and 3.2kgha−1 in rice, corn and soybean yields, respectively. According to the historical warming level, present cropping boundaries can be theoretically extended northward about 80km with a prolonged growing period by 10 days compared to the 1970s. Actually, the growth durations of newly approved varieties of rice, corn and soybean have really prolonged by 14.0 days, 7.0 days and 2.7 days since the 1950s, respectively. The actual growing periods of rice and corn have also respectively prolonged by 6 days and 4 days due to the adjustment of sown and harvest dates by the farmer since 1990s. The existing rice cropping region has been extended northward 80km in the 2006 compared to the 1970. These actual responses were consistent with the theoretical calculation according to the historical warming trends. Our results demonstrate that cropping system owns the potential to progressively and actively adapt to the global warming for high yield through a comprehensive strategy. [Copyright &y& Elsevier]

Abstract: Crop model projections and historical data analyses have shown that global warming may cause serious decrease in crop productivity, however, many uncertainities remain on the impact quantification due to the unclear understanding of actual crop response. Therefore, we performed a three-year field warming experiment with free air temperature increase (FATI) facility to investigate the actual response of midseason rice growth in East China. There were four treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming; CK: ambient control) with three replicates. This FATI facility presented a good simulation of the local air temperature pattern with an increase in the daily mean temperature of about 1.1–2.0°C during rice whole growth duration compared to the ambient control. Warming shortened the pre-heading phase respectively by 3.3d, 1.7d and 2.0d in the AW, DW and NW plots, while the post-heading phase stayed almost unchanged. During the three years, warming slightly decreased the aboveground biomass by an average of 9.1%, 10.3% and 3.3%, and the grain yield by an average of 0.9%, 6.4% and 6.1% in the AW, DW and NW plots, respectively. Warming tended to decrease rice photosynthesis rate and stimulate the nighttime respiration rate. It also enlarged the flag leaf area and increased its chlorophyll content. No significant difference and interaction in the actual response of rice growth were found between the warming regimes. The above evidences suggest that the expected warming less than 2.0°C may not cause significant decrease in rice productivity in East China. [Copyright &y& Elsevier]

Abstract: We examined the long-term effects of inorganic fertilizer (N and NPK) and manure application on soil aggregation and carbon (C) fractions under a double corn (Zea mays L.) cropping system in a subtropical red soil. Results showed that application of manure combined with NPK (NPK+M) gained the highest yield and increased the stability of crop production. Application of inorganic fertilizer could sustain soil organic carbon (SOC) concentrations, whereas long-term application of manure alone or combined with NPK (M and NPK+M) significantly increased SOC contents compared with the unfertilized control. Manure application significantly increased the proportion of large macroaggregates (>2000µm) compared with the control, while leading to a corresponding decline in the percentage of microaggregates (53–250µm). Carbon storage in the intra-aggregate particulate organic matter within microaggregates (iPOM_m) was enhanced from 9.8% of the total SOC stock in the control to 19.7% and 18.6% in the M and NPK+M treatments, respectively. The shift in SOC stocks towards microaggregates is beneficial for long-term soil C sequestration. Moreover, the differences in the microaggregate protected C (i.e., iPOM_m) accounted, on average, for 39.8% of the differences in total SOC stocks between the control and the manure-applied treatments. Thus, we suggest that the microaggregate protected C is promising for assessing the impact of long-term fertilization management on SOC storage in the red soil. [Copyright &y& Elsevier]

A better understanding of wheat cultivar impact on field N 2 O emissions could provide important information for cultivar improvement and selection to meet food security and greenhouse gas (GHG) mitigation. A 2-year field experiment was carried out from 2015 to 2017 on 12 leading cultivars released in the major winter wheat cropping regions of China since the 1940s. Field N 2 O emissions, wheat growth, and plant nitrogen uptake were determined. The results showed that both the cumulative and yield-scaled N 2 O emissions differed significantly among cultivars, varying on average from 1.64 to 2.10 kg N 2 O–N ha−1 and 232.65–529.37 mg N 2 O–N kg−1, respectively. As the wheat cultivar renewal progressed, the cumulative and yield-scaled N 2 O emissions declined significantly at the relative decrease rates of 0.2% yr−1 and 0.9% yr−1, respectively. In addition to wheat grain yield and biomass, amount of plant N uptake has been enhanced significantly over the past sixty years. The spike number per unit area, leaf dry matter, net photosynthesis rate, and transpiration rate also all increased, whereas wheat plant height decreased over the decades. Our findings demonstrate that lower N 2 O emissions can primarily be attributed to the greater N uptake of the newly high-yielding wheat cultivars, suggesting a great chance of ensuring food security and GHG mitigation simultaneously through cultivar selection and improvement. [Display omitted] • Both the cumulative and yield-scaled N 2 O emissions were lower with new wheat cultivars compared to old ones. • The reduction effects of yield-scaled N 2 O emissions with the cultivar improvement overperformed the cumulative N 2 O emissions. • Wheat yield and N uptake increased significantly along with the cultivar improvement. • Lower N 2 O emissions with new cultivars was associated with higher productivity and N uptake, and lower soil N availability. [ABSTRACT FROM AUTHOR]

• Long-term fertilization increased SOC content and decreased soil bulk density. • Long-term inorganic fertilizers mainly increased pores that are < 25 μm. • Long-term organic manures mainly increased pores that are > 25 μm. • Long-term organic manures optimize pore structure and improve soil aggregation. Inorganic fertilizers and organic manures have been widely used to maintain crop yields. Leguminous green manures are usually used in the paddy fields in southern China. But the effect of green manures or combination of green manures with other fertilizers on soil physical properties, especially soil pore structure, is unclear. Based on a 34-year field experiment, we investigated the effects of different fertilization strategies on soil structural properties of a paddy soil. Four treatments were selected: no amendment as a control (CK), inorganic fertilization of N, P and K (NPK), combined application of inorganic fertilizers and green manure (GM), and combined application of inorganic fertilizers, green manure and swine manure (GSM). Results showed that relative to the CK treatment, the NPK, GM and GSM treatments increased SOC content by 7.9 %, 17.8 % and 25.7 %, respectively (P < 0.05). The increase of SOC content led to increased aggregate water stability in the GSM treatment (P < 0.05) but not in the GM and NPK treatments (P > 0.05). Consistent with SOC, soil bulk density was reduced by 5.6 %, 7.4 % and 17.6 %, respectively, for the NPK, GM and GSM treatments (P < 0.05). Total porosity was significantly increased in all the fertilized treatments (P < 0.05). Detailed pore size distribution analysis revealed that the NPK treatment mainly increased < 25 μm pores (total porosity minus porosity of pores that are > 25 μm), while the GM and GSM treatments mainly increased > 25 μm pores. The GSM treatment also significantly increased the connectivity and fractal dimension of macropores (P < 0.05). The penetration resistance of the paddy soil was not affected by the different fertilization strategies, with a low (< 0.4 MPa) value at the plough layer (0−15 cm) and a high value (up to 1.6 MPa) at the plough pan (15−25 cm). Overall, this study indicated that inorganic fertilizers had beneficial, but limited effects on paddy soil structure. Green manure and swine manure can further improve soil pore structure and soil aggregation. [ABSTRACT FROM AUTHOR]