Publications by authors named "Fusuo Zhang"

157 Publications

Model-based analysis of phosphorus flows in the food chain at county level in China and options for reducing the losses towards green development.

Environ Pollut 2021 Jul 10;288:117768. Epub 2021 Jul 10.

College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil, Interactions, MOE, China Agricultural University, Beijing, 100193, China. Electronic address:

Insight in the phosphorus (P) flows and P balances in the food chain is largely unknown at county scale in China, being the most appropriate spatial unit for nutrient management advice. Here, we examined changes in P flows in the food chain in a typical agricultural county (Quzhou) during 1980-2017, using substance flow analyses. Our results show that external P inputs to the county by feed import and fertilizer were 7 times greater in 2017 than in 1980, resulting in a 7-fold increase in P losses to the environment in the last 3 decades, with the biggest source being animal production. Phosphorus use efficiency decreased from 51% to 30% in crop production (PUEc) and from 32% to 11% in the whole food chain (PUEf), but increased from 4% to 7% in animal production (PUEa). A strong reduction in P inputs and thus increase in PUE can be achieved by balanced P fertilization, which is appropriate for Quzhou considering a current average adequate soil P status. Fertilizer P use can be reduced from 7276 tons yr to 1765 tons yr to equal P removal by crops. This change would increase P use efficiency for crops from 30% to 86% but it has a negligible effect on P losses to landfills and water bodies. Increasing the recycling of manure P from the current 43%-95% would reduce fertilizer P use by 17% and reduce P losses by 47%. A combination of reduced fertilizer P use and increased recycling of manure P would save fertilizer P by 93%, reduce P accumulation by 100% and P loss by 49%. The results indicate that increasing manure-recycling and decreasing fertilizer-application are key to achieving sustainable P use in the food chain, which can be achieved through coupling crop-livestock systems and crop-based nutrient management.
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http://dx.doi.org/10.1016/j.envpol.2021.117768DOI Listing
July 2021

Deciphering microbial mechanisms underlying soil organic carbon storage in a wheat-maize rotation system.

Sci Total Environ 2021 Sep 15;788:147798. Epub 2021 May 15.

College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China. Electronic address:

A link between microbial life history strategies and soil organic carbon storage in agroecosystems is presumed, but largely unexplored at the gene level. We aimed to elucidate whether and how differential organic material amendments (manure versus peat-vermiculite) affect, relative to sole chemical fertilizer application, the link between microbial life history strategies and soil organic carbon storage in a wheat-maize rotation field experiment. To achieve this goal, we combined bacterial 16S rRNA gene and fungal ITS amplicon sequencing, metagenomics and the assembly of genomes. Fertilizer treatments had a significantly greater effect on microbial community composition than aggregate size, with soil available phosphorus and potassium being the most important community-shaping factors. Limitation in labile carbon was linked to a K-selected oligotrophic life history strategy (Gemmatimonadetes, Acidobacteria) under sole chemical fertilizer application; defined by a significant enrichment of genes involved in resource acquisition, polymer hydrolysis, and competition. By contrast, excess of labile carbon promoted an r-selected copiotrophic life history strategy (Cytophagales, Bacillales, Mortierellomycota) under manure treatment; defined by a significant enrichment of genes involved in cellular growth. A distinct life history strategy was not observed under peat-vermiculite treatment, but rather a mix of both K-selected (Acidobacteria) and r-selected (Actinobacteria, Mortierellomycota) microorganisms. Compared to sole chemical fertilizer application, soil organic carbon storage efficiency was significantly increased by 26.5% and 50.0% under manure and peat-vermiculite treatments, respectively. Taken together, our results highlight the importance of organic material amendments, but in particular a one-time peat-vermiculite application, to promote soil organic carbon storage as a potential management strategy for sustainable agriculture.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147798DOI Listing
September 2021

Metagenomic insights into nitrogen and phosphorus cycling at the soil aggregate scale driven by organic material amendments.

Sci Total Environ 2021 Sep 24;785:147329. Epub 2021 Apr 24.

College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China. Electronic address:

The soil microbiome, existing as interconnected communities closely associated with soil aggregates, is the key driver in nutrient cycling. However, the underlying genomic information encoding the machinery of the soil microbiome involved in nutrient cycling at the soil aggregate scale is barely known. Here comparative metagenomics and genome binning were applied to investigate microbial functional profiles at the soil aggregate scale under different organic material amendments in a long-term field experiment. Soil samples were sieved into large macroaggregates (>2 mm), macroaggregates (0.25-2 mm) and microaggregates (<0.25 mm). Microbial taxonomic and functional alpha diversity were significantly correlated to soil NO and SOC. The highest abundance of nasB, nirK, and amoA genes, which are responsible for denitrification and ammonia oxidizers driving nitrification, was observed in microaggregates. Both manure and peat treatments significantly decreased the abundance of napA and nrfA that encode enzymes involved in dissimilatory nitrate reduction to ammonium (DNRA). As a biomarker for soil inorganic P solubilization, the relative abundance of gcd was significantly increased in macroaggregates and large macroaggregates. Three nearly complete genomes of Nitrososphaeraceae (AOA) and seven bacterial genomes were shown to harbor a series of genes involved in nitrification and P solubilization, respectively. Our study provides comprehensive insights into the microbial genetic potential for DNRA and P-solubilizing activity across different soil aggregate fractions and fertilization regimes.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147329DOI Listing
September 2021

Atmospheric nitrogen deposition: A review of quantification methods and its spatial pattern derived from the global monitoring networks.

Ecotoxicol Environ Saf 2021 Apr 14;216:112180. Epub 2021 Apr 14.

College of Resources and Environmental Sciences; National Academy of Agriculture Green Development; Key Laboratory of Plant-Soil Interactions of MOE, China Agricultural University, Beijing 100193, China.

Atmospheric nitrogen (N) deposition is a vital component of the global N cycle. Excessive N deposition on the Earth's surface has adverse impacts on ecosystems and humans. Quantification of atmospheric N deposition is indispensable for assessing and addressing N deposition-induced environmental issues. In the present review, we firstly summarized the current methods applied to quantify N deposition (wet, dry, and total N deposition), their advantages and major limitations. Secondly, we illustrated the long-term N deposition monitoring networks worldwide and the results attained via such long-term monitoring. Results show that China faces heavier N deposition than the United States, European countries, and other countries in East Asia. Next, we proposed a framework for estimating the atmospheric wet and dry N deposition using a combined method of surface monitoring, modeling, and satellite remote sensing. Finally, we put forth the critical research challenges and future directions of the atmospheric N deposition. CAPSULE: A review of quantification methods and the global data on nitrogen deposition and a systematic framework was proposed for quantifying nitrogen deposition.
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http://dx.doi.org/10.1016/j.ecoenv.2021.112180DOI Listing
April 2021

Mitigation of Multiple Environmental Footprints for China's Pig Production Using Different Land Use Strategies.

Environ Sci Technol 2021 04 1;55(8):4440-4451. Epub 2021 Apr 1.

College of Resources and Environmental Sciences; National Academy of Agriculture Green Development; Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China.

Pig production contributes considerably to land use and greenhouse gas (GHG) and reactive nitrogen (Nr) emissions. Land use strategies were widely proposed, but the spillover effects on biological flow are rarely explored. Here, we simultaneously assessed the carbon (C), nitrogen (N), and cropland footprints of China's pig production at the provincial scale in 2017. The environmental impacts of land use strategies were further evaluated. Results show that one kg live-weight pig production generated an average of 1.9 kg CO-equiv and 59 g Nr emissions, occupying 3.5 m cropland, with large regional variations. A large reduction in GHG (58-64%) and Nr (12-14%) losses and occupied cropland (10-11%) could be achieved simultaneously if combined strategies of intensive crop production, improved feed-protein utilization efficiency, and feeding co-products were implemented. However, adopting a single strategy may have environmental side-effects. Reallocating cropland that pigs used for feed to plant food alternatives would enhance human-edible energy (3-20 times) and protein delivery (1-5 times) and reduce C and N footprints, except for rice and vegetables. Reallocating cropland to beef and milk production would decrease energy and protein supply. Therefore, a proper combination of land use strategies is essential to alleviate land use changes and nutrient emissions without sacrificing food supply.
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http://dx.doi.org/10.1021/acs.est.0c08359DOI Listing
April 2021

Optimizing wheat production and reducing environmental impacts through scientist-farmer engagement: Lessons from the North China Plain.

Food Energy Secur 2021 Feb 4;10(1):e255. Epub 2020 Nov 4.

National Academy of Agriculture Green Development Department of Plant Nutrition, College of Resources and Environmental Sciences China Agricultural University Beijing 100193 China.

Producing high economic benefits and high grain yields with limited environmental impacts is crucial for feeding the world's growing population. Yet it remains challenging to improve the performance of one objective without creating unintended consequences for other objectives. This is especially difficult for smallholders navigating a diverse array of environmental and personal demands. This study demonstrates how combining participatory research through the Science and Technology Backyards (STB) approach with Pareto-based ranking modeling can increase smallholder production while also reducing environmental impact. Through an intensive farmer survey in a 1 × 1 km grid in Quzhou County, we demonstrate that farmers engaged in STBs performed better according to multiple objectives (i.e., optimizing overall grain yield, benefit-cost ratio, and GHG emissions, without compromising any one of these objectives) than farmer's not engaged in STBs. Moreover, we used a Pareto optimization approach (OPT) to determine the optimal smallholder scenario. We found that under OPT, grain yield could reach 9.5 t/ha, with a benefit-cost ratio of 2.1, a 100% N recovery efficiency, and 7,395 kg COeq ha GHG emissions. With OPT as a final goal, our research team worked with STB farmers to improve economic and environmental outcomes without compromising yield. Our findings demonstrate that no significant difference was obtained between farmers engaged in STBs and these under OPT. Compared with non-STB farmers, STB farmers' grain yield improved by 18%, benefit-cost ratio improved by 26% due to improved N recovery efficiency, and GHG emissions were reduced by 31%. These improvements demonstrate the power of scientist-farmer engagement for optimizing wheat production. Such engagement allows farmers to modify their agronomic practices to more closely match Pareto optimal conditions, thus improving environmental and economic benefits without compromising yield. Our results provide solid evidence of the potential for sustainable wheat production by combining modeling with participatory research.
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http://dx.doi.org/10.1002/fes3.255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7988609PMC
February 2021

Microbial metabolic response to winter warming stabilizes soil carbon.

Glob Chang Biol 2021 May 13;27(10):2011-2028. Epub 2021 Feb 13.

Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.

Current consensus on global climate change predicts warming trends with more pronounced temperature changes in winter than summer in the Northern Hemisphere at high latitudes. Moderate increases in soil temperature are generally related to faster rates of soil organic carbon (SOC) decomposition in Northern ecosystems, but there is evidence that SOC stocks have remained remarkably stable or even increased on the Tibetan Plateau under these conditions. This intriguing observation points to altered soil microbial mediation of carbon-cycling feedbacks in this region that might be related to seasonal warming. This study investigated the unexplained SOC stabilization observed on the Tibetan Plateau by quantifying microbial responses to experimental seasonal warming in a typical alpine meadow. Ecosystem respiration was reduced by 17%-38% under winter warming compared with year-round warming or no warming and coincided with decreased abundances of fungi and functional genes that control labile and stable organic carbon decomposition. Compared with year-round warming, winter warming slowed macroaggregate turnover rates by 1.6 times, increased fine intra-aggregate particulate organic matter content by 75%, and increased carbon stabilized in microaggregates within stable macroaggregates by 56%. Larger bacterial "necromass" (amino sugars) concentrations in soil under winter warming coincided with a 12% increase in carboxyl-C. These results indicate the enhanced physical preservation of SOC under winter warming and emphasize the role of soil microorganisms in aggregate life cycles. In summary, the divergent responses of SOC persistence in soils exposed to winter warming compared to year-round warming are explained by the slowing of microbial decomposition but increasing physical protection of microbially derived organic compounds. Consequently, the soil microbial response to winter warming on the Tibetan Plateau may cause negative feedbacks to global climate change and should be considered in Earth system models.
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http://dx.doi.org/10.1111/gcb.15538DOI Listing
May 2021

Targeting Low-Phytate Soybean Genotypes Without Compromising Desirable Phosphorus-Acquisition Traits.

Front Genet 2020 14;11:574547. Epub 2020 Dec 14.

College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China.

Phytate-phosphorus (P) in food and feed is not efficiently utilized by humans and non-ruminant livestock, potentially contributing to high losses of P to the environment. Crops with high P-acquisition efficiency can access soil P effectively. It remains elusive whether crop genotypes with high P-acquisition efficiency can also have low seed phytate concentrations. A core collection of 256 soybean [ (L.) Merr.] genotypes from China with diverse genetic background were grown in the same environment and seeds were sampled to screen for seed phytate-P concentration. Some of these genotypes were also grown in a low-P soil in the glasshouse to measure root morphological and physiological traits related to P acquisition. Large genotypic variation was found in seed phytate-P concentration (0.69-5.49 mg P g dry weight), total root length, root surface area, rhizosheath carboxylates, and acid phosphatase activity in rhizosheath soil. Geographically, seed phytate-P concentration was the highest for the genotypes from Hainan Province, whereas it was the lowest for the genotypes from Inner Mongolia. Seed phytate-P concentration showed no correlation with any desirable root traits associated with enhanced P acquisition. Two genotypes (Siliyuan and Diliuhuangdou-2) with both low phytate concentrations and highly desirable P-acquisition traits were identified. This is the first study to show that some soybean genotypes have extremely low seed phytate concentrations, combined with important root traits for efficient P acquisition, offering material for breeding genotypes with low seed phytate-P concentrations.
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http://dx.doi.org/10.3389/fgene.2020.574547DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7767974PMC
December 2020

Global direct nitrous oxide emissions from the bioenergy crop sugarcane (Saccharum spp. inter-specific hybrids).

Sci Total Environ 2021 Jan 20;752:141795. Epub 2020 Aug 20.

Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; Center for Resources, Environment and Food Security, China Agricultural University, Beijing 100193, China. Electronic address:

Sugarcane is the second largest bioenergy crop in the world and it accounts for 80% of global sugar production. Grown mostly in wet and warm tropics with relatively high nitrogen (N) fertiliser input and crop residue retention, sugarcane production is a significant source of nitrous oxide (NO) emission. Yet, a global evaluation of research on NO emission from sugarcane crop is lacking. Here, we conducted a meta-analysis using data from 141 measurements compiled from 15 sugarcane field studies reported from different countries to i) quantify NO emissions and emission factors (EFs) globally, and for tropics and sub-tropics, and ii) identify the key factors that promote NO emission. Our analysis shows that the global mean total NO emission from sugarcane production reached 2.26 (CI: 1.93-2.62) kg NO-N ha yr with an estimated EF of 1.21% (CI: 0.971-1.46%). NO emissions increased exponentially with increase in N fertiliser rate, questioning the adequacy of Intergovernmental Panel on Climate Change (IPCC) default EF value (1%) for sugarcane NO emission estimation. Mean total NO emissions and EFs in tropics and sub-tropics did not vary significantly. Supplementing synthetic N fertiliser (SN) with organic amendments (OA) significantly increased mean NO emission (~1.4-fold) and EF (~2.5-fold) compared to SN. A remarkable reduction in NO emission (38.6%) and EF (61.5%) was evident when enhanced efficiency fertilisers (EEF) replaced SN. In contrast, crop residue removal had little impact on NO emission and EF, but both parameters showed an upward trend with irrigation and increased rainfall. Soil carbon content and pH were emerged as key regulators of sugarcane NO emission and EF. It is concluded that global sugarcane NO emission could be significant and that there is considerable prospect for mitigating the emission through innovative nutrient formulations and precision agriculture that help meet crop nutrient demand without compromising environmental imperatives.
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http://dx.doi.org/10.1016/j.scitotenv.2020.141795DOI Listing
January 2021

Sustainable Cropping Requires Adaptation to a Heterogeneous Rhizosphere.

Trends Plant Sci 2020 12 21;25(12):1194-1202. Epub 2020 Aug 21.

Department of Plant Nutrition, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Beijing 100193, PR China. Electronic address:

Root-soil interactions in the rhizosphere are central to resource acquisition and crop production in agricultural systems. However, apart from studies in idealized experimental systems, rhizosphere processes in real agricultural soils in situ are largely uncharacterized. This limits the contribution of rhizosphere science to agriculture and the ongoing Green Revolution. Here, we argue that understanding plant responses to soil heterogeneity is key to understanding rhizosphere processes. We highlight rhizosphere sensing and root-induced soil modification in the context of heterogeneous soil structure, resource distribution, and root-soil interactions. A deeper understanding of the integrated and dynamic root-soil interactions in the heterogeneously structured rhizosphere could increase crop production and resource use efficiency towards sustainable agriculture.
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http://dx.doi.org/10.1016/j.tplants.2020.07.006DOI Listing
December 2020

Changes of nitrogen deposition in China from 1980 to 2018.

Environ Int 2020 11 11;144:106022. Epub 2020 Aug 11.

Key Laboratory of Plant-Soil Interactions of MOE, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing 100193, China. Electronic address:

China has experienced a dramatic change in atmospheric reactive nitrogen (Nr) emissions over the past four decades. However, it remains unclear how nitrogen (N) deposition has responded to increases and/or decreases in Nr emissions. This study quantitatively assesses temporal and spatial variations in measurements of bulk and calculated dry N deposition in China from 1980 to 2018. A long-term database (1980-2018) shows that bulk N deposition peaked in around 2000, and had declined by 45% by 2016-2018. Recent bulk and dry N deposition (based on monitoring from 2011 to 2018) decreased from 2011 to 2018, with current average values of 19.4 ± 0.8 and 20.6 ± 0.4 kg N ha yr, respectively. Oxidized N deposition, especially dry deposition, decreased after 2010 due to NO emission controls. In contrast, reduced N deposition was approximately constant, with reductions in bulk NH-N deposition offset by a continuous increase in dry NH deposition. Elevated NH concentrations were found at nationwide monitoring sites even at urban sites, suggesting a strong influence of both agricultural and non-agricultural sources. Current emission controls are reducing Nr emissions and deposition but further mitigation measures are needed, especially of NH, built on broader regional emission control strategies.
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http://dx.doi.org/10.1016/j.envint.2020.106022DOI Listing
November 2020

Impacts of nitrogen fertilizer type and application rate on soil acidification rate under a wheat-maize double cropping system.

J Environ Manage 2020 Sep 14;270:110888. Epub 2020 Jun 14.

Environmental Systems Analysis Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; Alterra-Wageningen UR, Soil Science Centre, P.O. Box 47, 6700 AA, Wageningen, the Netherlands.

Nitrogen (N) fertilizer-induced soil acidification in Chinese croplands is well-known, but insight in the impacts of different N fertilizer management approaches (fertilizer type and rate) on soil acidification rates is very limited. Here, we conducted a field experiment on a moderate acid soil to quantify soil acidification rates in response to N fertilization by different fertilizer types and N rates through monitoring the fate of elements (mainly nutrients) related to H production and consumption. Two N fertilizer types (urea and NHCl) and three N rates (control, optimized and conventional, 0/120/240 kg N ha for wheat, 0/160/320 kg N ha for maize) were included. Nitrogen addition led to an average H production of 4.0, 8.7, 11.4, 29.7 and 52.6 keq ha yr, respectively, for the control, optimized urea, conventional urea, optimized NHCl and conventional NHCl plots. This was accompanied with a decline in soil base saturation of 1-10% and in soil pH of 0.1-0.7 units in the topsoil (0-20 cm). Removal of base cations by crop harvesting and N transformations contributed ~70% and ~20% to the H production in the urea treated plots, being ~20% and ~75% in the NHCl treated plots, respectively. The large NH input via fertilization in the NHCl treated plots strongly enhanced the H production induced by N transformations. The low contribution of N transformations to the H production in the urea treated plots was due to the limited NO leaching, induced by the high N losses to air caused by denitrification. Increased N addition by urea, however, strongly increased H production by enhanced plant uptake of base cations, mainly due to a large potassium uptake in straw. Our results highlight the important role of optimizing fertilizer form and N rate as well as straw return to the field in alleviating soil acidification.
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http://dx.doi.org/10.1016/j.jenvman.2020.110888DOI Listing
September 2020

Syndromes of production in intercropping impact yield gains.

Nat Plants 2020 06 1;6(6):653-660. Epub 2020 Jun 1.

Centre for Crop Systems Analysis, Wageningen University, Wageningen, The Netherlands.

Intercropping, the simultaneous production of multiple crops on the same field, provides opportunities for the sustainable intensification of agriculture if it can provide a greater yield per unit land and fertilizer than sole crops. The worldwide absolute yield gain of intercropping as compared with sole crops has not been analysed. We therefore performed a global meta-analysis to quantify the effect of intercropping on the yield gain, exploring the effects of crop species combinations, temporal and spatial arrangements, and fertilizer input. We found that the absolute yield gains, compared with monocultures, were the greatest for mixtures of maize with short-grain cereals or legumes that had substantial temporal niche differentiation from maize, when grown with high nutrient inputs, and using multirow strips of each species. This approach, commonly practised in China, provided yield gains that were (in an absolute sense) about four times as large as those in another, low-input intercropping strategy, commonly practised outside China. The alternative intercropping strategy consisted of growing mixtures of short-stature crop species, often as full mixtures, with the same growing period and with low to moderate nutrient inputs. Both the low- and high-yield intercropping strategies saved 16-29% of the land and 19-36% of the fertilizer compared with monocultures grown under the same management as the intercrop. The two syndromes of production in intercropping uncovered by this meta-analysis show that intercropping offers opportunities for the sustainable intensification of both high- and low-input agriculture.
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http://dx.doi.org/10.1038/s41477-020-0680-9DOI Listing
June 2020

Phosphorus flow analysis in the maize based food-feed-energy systems in China.

Environ Res 2020 05 2;184:109319. Epub 2020 Mar 2.

College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, PR China.

Phosphorus (P) is an essential and limiting nutrient for agricultural systems, where the demand for agricultural products such as food, feed, and bio-fuel are the major drivers of the intensification of agricultural production systems. Globally, maize is one of three main cereal crops, a main feedstock for animal production and a substrate for the production of bio-ethanol. This study investigated P flows through the multiple utilization systems of maize (as represented by the subsystems of food, feed and energy production) at a crop level of 2016 as reference year and made future predictions of P flows for the year 2030 based on different scenarios for food-feed-energy systems in China. For 2016, the subsystem of animal production resulted in the highest waste of P due to inappropriate manure management, but the subsystem of value-added products (Bio-fuel production, distillers dried grains with solubles (DDGS), maize-oil) showed the lowest P use efficiency (39%). From the value-added subsystem, 17% of P from the process flow to the subsystem of animal production as DDGS, and 61% of P is wasted associated with wastewater and sludge. Future scenarios of structural adjustments in the maize consumption system predict that the supply of maize for animal feed will be threatened if the policy of the Biofuel National Promotion before 2020 is fully implemented in China, as current maize production will not meet the future demand of food, feed and energy simultaneously. The results emphasized the use of P waste resources and better sludge management from a systems perspective. This also implied the importance of exploring coordinated development and integrated strategies for sustainable P flow management in multiple utilization systems.
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http://dx.doi.org/10.1016/j.envres.2020.109319DOI Listing
May 2020

Magnesium Fertilization Improves Crop Yield in Most Production Systems: A Meta-Analysis.

Front Plant Sci 2019 24;10:1727. Epub 2020 Jan 24.

Department of Plant Nutrition, The Key Plant-Soil Interaction Lab, MOE, China Agricultural University, Beijing, China.

Magnesium deficiency is a frequently occurring limiting factor for crop production due to low levels of exchangeable Mg (ex-Mg) in acidic soil, which negatively affects sustainability of agriculture development. How Mg fertilization affects crop yield and subsequent physiological outcomes in different crop species, as well as agronomic efficiencies of Mg fertilizers, under varying soil conditions remain particular interesting questions to be addressed. A meta-analysis was performed with 570 paired observations retrieved from 99 field research articles to compare effects of Mg fertilization on crop production and corresponding agronomic efficiencies in different production systems under varying soil conditions. The mean value of yield increase and agronomic efficiency derived from Mg application was 8.5% and 34.4 kg kg respectively, when combining all yield measurements together, regardless of the crop type, soil condition, and other factors. Under severe Mg deficiency (ex-Mg < 60 mg kg), yield increased up to 9.4%, nearly two folds of yield gain (4.9%) in the soil containing more than 120 mg kg ex-Mg. The effects of Mg fertilization on yield was 11.3% when soil pH was lower than 6.5. The agronomic efficiency of Mg fertilizers was negatively correlated with application levels of Mg, with 38.3 kg kg at lower MgO levels (0-50 kg ha) and 32.6 kg kg at higher MgO levels (50-100 kg ha). Clear interactions existed between soil ex-Mg, pH, and types and amount of Mg fertilizers in terms of crop yield increase. With Mg supplementation, Mg accumulation in the leaf tissues increased by 34.3% on average; and concentrations of sugar in edible organs were 5.5% higher compared to non-Mg supplemented treatments. Our analysis corroborated that Mg fertilization enhances crop performance by improving yield or resulting in favorable physiological outcomes, providing great potentials for integrated Mg management for higher crop yield and quality.
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http://dx.doi.org/10.3389/fpls.2019.01727DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6992656PMC
January 2020

Modelling long-term impacts of fertilization and liming on soil acidification at Rothamsted experimental station.

Sci Total Environ 2020 Apr 26;713:136249. Epub 2019 Dec 26.

Wageningen University and Research, Environmental Systems Analysis Group, PO Box 47, 6700AA Wageningen, the Netherlands; Wageningen University and Research, Environmental Research, PO Box 47, 6700AA Wageningen, the Netherlands. Electronic address:

Liming is widely used to reduce the impacts of soil acidification and optimize soil pH for agricultural production. Whether models can simulate the effect of liming on soil pH, and base saturation (BS), and thereby guide lime application, is still largely unknown. Long-term experimental data from a grassland (Park Grass, 1965-2012) and arable land (Sawyers Field, 1962-1972) at Rothamsted Research, UK, were thus used to assess the ability of the VSD+ model to simulate the effects of long-term fertilization and liming on soil acidification. The VSD+ model was capable of simulating observed soil pH and BS changes over time in the long-term liming experiments, except for a treatment in which sulphur (S) was added. Normalized Mean Absolute Errors (NMAE) and Normalized Root Mean Square Errors (NRMSE) of simulated and observed pH values, averaged over the observation periods varied between 0.02 and 0.08 (NMAE) and 0.01-0.05 (NRMSE). The acidity budget results for Park Grass suggest that nitrogen (N) transformations contributed most to acidity production, causing predominantly aluminium (Al) exchange in the topsoil (0-23 cm) followed by base cation (BC) release, but in the treatment with S addition, BC uptake had a nearly similar effect on acidity production. However, in Sawyers Field, the acidity budget suggested that BC uptake was the dominant cause of soil acidification, while the impacts of N transformations were limited. Liming was found to sufficiently replenish BC and decrease Al exchange in the topsoil layer. Overall, the VSD+ model can adequately reconstruct the impacts of fertilizer and liming applications on acid neutralizing processes and related soil pH and BC changes at the soil exchange complex.
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http://dx.doi.org/10.1016/j.scitotenv.2019.136249DOI Listing
April 2020

Spatio-temporal patterns of air pollution in China from 2015 to 2018 and implications for health risks.

Environ Pollut 2020 Mar 23;258:113659. Epub 2019 Nov 23.

College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions of MOE, China Agricultural University, Beijing, 100193, China.

China has been seriously affected by particulate matter (PM) and gaseous pollutants in the atmosphere. In this study, we systematically analyse the spatio-temporal patterns of PM, PM, SO, CO, NO, and O and the associated health risks, using data collected from 1498 national air quality monitoring sites. An analysis of the averaged data from all the sites indicated that, from 2015 to 2018, annual mean concentrations of PM, PM, SO and CO declined by 3.2 μg m, 3.7 μg m, 3.9 μg m, and 0.1 mg m, respectively. In contrast, those of NO and O increased at rates of 0.4 and 3.1 μg m, respectively. Except for O, the annual mean concentrations of all pollutants were generally the highest in North China and lowest in the Tibetan Plateau. The concentrations were generally higher in the north of the country than in the south. In all regions of China, the pollutant concentrations were the highest in winter and lowest in summer, except for O, which showed an opposite seasonal pattern. Overall, the seasonal mean concentrations of all the pollutants (except for O) significantly decreased between the same seasons in 2018 and 2015, whereas the seasonal mean O concentrations generally significantly increased, and/or remained at stable levels in all four seasons except for winter. Diurnal variations of all pollutants (except for O) exhibited a bimodal pattern with peaks between 8:00 and 11:00 a.m. and 9:00 and 12:00 p.m., whereas O exhibited a unimodal pattern with maximum values between 5:00 and 7:00 p.m. No significant differences in the daily mean concentrations of all pollutants were found between weekdays and weekends in all regions, except for PM and PM in Northeast China. In Northwest China and Southeast China, PM showed stronger correlations with NO relative to SO, suggesting that NO emission control may be more effective than SO emission control for alleviating PM formation. Compared with 2015, the total PM-attributable mortality, number of respiratory and cardiovascular diseases, and incidence of chronic bronchitis decreased overall by 23.4%-26.9% in 2018. In contrast, for O-attributable deaths, there was an increase of 18.9%. Our study not only improves the understanding of the spatial and temporal patterns of air pollutants in China, but also highlights that synchronous control of PM and O pollution should be implemented to achieve dual benefits in protecting human health.
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http://dx.doi.org/10.1016/j.envpol.2019.113659DOI Listing
March 2020

Cropland acidification increases risk of yield losses and food insecurity in China.

Environ Pollut 2020 Jan 12;256:113145. Epub 2019 Sep 12.

Wageningen University and Research, Environmental Systems Analysis Group, PO Box 47, 6700, AA Wageningen, the Netherlands; Wageningen Environmental Research, P.O. Box 47, 6700, AA Wageningen, the Netherlands.

Distinct cropland acidification has been reported in China due to nitrogen (N) fertilizer overuse. However, the impacts on food production and thereby on food security are largely unknown. Yield losses in the period 1980-2050 were therefore assessed by simulating soil pH changes combined with derived pH-yield relationships for wheat, maize and rice. If the N fertilizer input continues to increase at 1% annually, the predicted average soil pH decline is about one unit and relative yield losses are expected to increase from approximately 4%-24% during 2010-2050. If the N fertilizer increase stops in 2020 (N2020), the expected losses are approximately 16% in 2050, which is comparable to a scenario of 100% crop residue return (100%RR). However, if 30% of the N fertilizer is replaced by manure N (30%MR), the losses reduce to near 5% in 2050. Soil acidification was predicted to reverse and expected losses are only 2.5% in 2050 in a combined scenario of N2020, 100%RR and 30%MR. Our results illustrate the potential food insecurity induced by cropland acidification and address the necessity of mitigation.
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http://dx.doi.org/10.1016/j.envpol.2019.113145DOI Listing
January 2020

Management Strategies to Optimize Soil Phosphorus Utilization and Alleviate Environmental Risk in China.

J Environ Qual 2019 Sep;48(5):1167-1175

In the last decade, crop production in China has dramatically improved due to greater phosphorus (P) input. As P fertilizer application rates increased from 88 to 123 kg PO ha yr during 2004 to 2014, total P use efficiency (total P output in crops as a percentage of total P input) dropped from 68 to 20%, leading to an accumulation of >90 kg PO ha in the soil each year. Phosphorus lost from agriculture is the second greatest contributor to waterbody eutrophication in China, accounting for 25% of total P losses in 2010; the main contributor is livestock husbandry. Given these problems, as well as the finite nature of P reserves, three strategies are proposed here to reduce P fertilizer application rates, improve P use efficiency, and minimize the environmental risk caused by P loss in China: (i) improving soil legacy P utilization by modifying cropping systems, rhizosphere management, or microbial engineering, (ii) increasing P use efficiency by reducing P fertilizer applications and minimizing P fertilizer fixation, and (iii) promoting the extension of soil P management strategies. For these management strategies to succeed in China, close cooperation should be established among farmers, scientists, and governments in the future.
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http://dx.doi.org/10.2134/jeq2019.02.0054DOI Listing
September 2019

Neighbouring plants modify maize root foraging for phosphorus: coupling nutrients and neighbours for improved nutrient-use efficiency.

New Phytol 2020 04 29;226(1):244-253. Epub 2019 Oct 29.

Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, China Agricultural University, Ministry of Education, Beijing, 100193, China.

Nutrient distribution and neighbours can impact plant growth, but how neighbours shape root-foraging strategy for nutrients is unclear. Here, we explore new patterns of plant foraging for nutrients as affected by neighbours to improve nutrient acquisition. Maize (Zea mays) was grown alone (maize), or with maize (maize/maize) or faba bean (Vicia faba) (maize/faba bean) as a neighbour on one side and with or without a phosphorus (P)-rich zone on the other in a rhizo-box experiment. Maize demonstrated root avoidance in maize/maize, with reduced root growth in 'shared' soil, and increased growth away from its neighbours. Conversely, maize proliferated roots in the proximity of neighbouring faba bean roots that had greater P availability in the rhizosphere (as a result of citrate and acid phosphatase exudation) compared with maize roots. Maize proliferated more roots, but spent less time to reach, and grow out of, the P patches away from neighbours in the maize/maize than in the maize/faba bean experiment. Maize shoot biomass and P uptake were greater in the heterogeneous P treatment with maize/faba bean than with maize/maize system. The foraging strategy of maize roots is an integrated function of heterogeneous distribution of nutrients and neighbouring plants, thus improving nutrient acquisition and maize growth. Understanding the foraging patterns is critical for optimizing nutrient management in crops.
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http://dx.doi.org/10.1111/nph.16206DOI Listing
April 2020

Benefits and trade-offs of replacing synthetic fertilizers by animal manures in crop production in China: A meta-analysis.

Glob Chang Biol 2020 02 26;26(2):888-900. Epub 2019 Oct 26.

College of Resources and Environmental Sciences, China Agricultural University, Beijing, PR China.

Recycling of livestock manure to agricultural land may reduce the use of synthetic fertilizer and thereby enhance the sustainability of food production. However, the effects of substitution of fertilizer by manure on crop yield, nitrogen use efficiency (NUE), and emissions of ammonia (NH ), nitrous oxide (N O) and methane (CH ) as function of soil and manure properties, experimental duration and application strategies have not been quantified systematically and convincingly yet. Here, we present a meta-analysis of these effects using results of 143 published studies in China. Results indicate that the partial substitution of synthetic fertilizers by manure significantly increased the yield by 6.6% and 3.3% for upland crop and paddy rice, respectively, but full substitution significantly decreased yields (by 9.6% and 4.1%). The response of crop yields to manure substitution varied with soil pH and experimental durations, with relatively large positive responses in acidic soils and long-term experiments. NUE increased significantly at a moderate ratio (<40%) of substitution. NH emissions were significantly lower with full substitution (62%-77%), but not with partial substitution. Emissions of CH from paddy rice significantly increased with substitution ratio (SR), and varied by application rates and manure types, but N O emissions decreased. The SR did not significantly influence N O emissions from upland soils, and a relative scarcity of data on certain manure characteristic was found to hamper identification of the mechanisms. We derived overall mean N O emission factors (EF) of 0.56% and 0.17%, as well as NH EFs of 11.1% and 6.5% for the manure N applied to upland and paddy soils, respectively. Our study shows that partial substitution of fertilizer by manure can increase crop yields, and decrease emissions of NH and N O, but depending on site-specific conditions. Manure addition to paddy rice soils is recommended only if abatement strategies for CH emissions are also implemented.
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http://dx.doi.org/10.1111/gcb.14826DOI Listing
February 2020

Phosphorus mitigation remains critical in water protection: A review and meta-analysis from one of China's most eutrophicated lakes.

Sci Total Environ 2019 Nov 21;689:1336-1347. Epub 2019 Jun 21.

School of Life Sciences, Arizona State University, Tempe, AZ, USA.

The processes of urbanization and industrialization within geological phosphorus-rich mountains (GPMn) have resulted in water degradation within southwest China. Lake Dianchi, one of the most eutrophicated lakes in China, has epitomized this issue. Clear understandings of phosphorus (P) mitigation efforts, the evolution of P budgets, and possible risks in the Dianchi system will benefit future eutrophication control, providing valuable lessons for other plateau freshwater lakes. In this study, we applied systematic review methodology to investigate the above questions, and then compared the results with other lakes worldwide. Generally, meta-analytical approaches have indicated P levels remain a key factor in causing algal blooms. Post-2015, the P budget of the Dianchi system, especially in Caohai section, was modified. However, it's still experiencing high pressures from P enrichment (Caohai: 0.4 mg·l; Waihai: 0.2 mg·l). The flux of P in Dianchi remains high, both through the external P load (556 ton·a), and an internal cycle (304 ton·a associated with the absorption, deposition and removal of algae biomass; and 380 ton·a associated with sediment exchange). Meanwhile, significant P retention has been observed in the lake, in particular within the Waihai section (211 ton·a). Currently, water diversion (from external watersheds), sewage diversion, and sediment-dredging projects have benefited Dianchi. However, continuous urbanization and GPMn ecological degradation could introduce hundreds of tons of additional P, leading to subsequent algal blooms. Furthermore, beyond Lake Dianchi, other lakes and reservoirs in southwest China are facing similar issues regarding P mitigation, especially in GPMn regions, though corresponding knowledge is still limited. Therefore, effective and flexible sub-regional protection strategies and research related to external and internal P mitigations have become key requirements for Lake Dianchi management. Meanwhile, ecologically sensitive approaches to GPMn regions, as well as city development within basin and market driven treatments, should be incorporated into regional water source protection for southwest China.
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http://dx.doi.org/10.1016/j.scitotenv.2019.06.302DOI Listing
November 2019

Soil microbiome mediates positive plant diversity-productivity relationships in late successional grassland species.

Ecol Lett 2019 Aug 27;22(8):1221-1232. Epub 2019 May 27.

Kansas Biological Survey, University of Kansas, Lawrence, KS, 66045, USA.

Which processes drive the productivity benefits of biodiversity remain a critical, but unanswered question in ecology. We tested whether the soil microbiome mediates the diversity-productivity relationships among late successional plant species. We found that productivity increased with plant richness in diverse soil communities, but not with low-diversity mixtures of arbuscular mycorrhizal fungi or in pasteurised soils. Diversity-interaction modelling revealed that pairwise interactions among species best explained the positive diversity-productivity relationships, and that transgressive overyielding resulting from positive complementarity was only observed with the late successional soil microbiome, which was both the most diverse and exhibited the strongest community differentiation among plant species. We found evidence that both dilution/suppression from host-specific pathogens and microbiome-mediated resource partitioning contributed to positive diversity-productivity relationships and overyielding. Our results suggest that re-establishment of a diverse, late successional soil microbiome may be critical to the restoration of the functional benefits of plant diversity following anthropogenic disturbance.
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http://dx.doi.org/10.1111/ele.13273DOI Listing
August 2019

Exploring Future Food Provision Scenarios for China.

Environ Sci Technol 2019 02 22;53(3):1385-1393. Epub 2019 Jan 22.

Center for Resources, Environment and Food Security , China Agricultural University , Beijing 100193 , China.

Developing sustainable food systems is essential, especially for emerging economies, where food systems are changing rapidly and affect the environment and natural resources. We explored possible future pathways for a sustainable food system in China, using multiple environmental indicators linked to eight of the Sustainable Development Goals (SDGs). Forecasts for 2030 in a business as usual scenario (BAU) indicate increases in animal food consumption as well as increased shortages of the land available and the water needed to produce the required food in China. Associated greenhouse gas emissions and nitrogen and phosphorus losses could become 10-42% of global emissions in 2010. We developed three main pathways besides BAU [produce more and better food (PMB), consume and waste less food (CWL), and import more food (IMF)] and analyzed their impacts and contributions to achieving one or more of the eight SDGs. Under these scenarios, the demand for land and water and the emissions of GHG and nutrients may decrease by 7-55% compared to BAU, depending on the pathway followed. A combination of PMB and CWL was most effective, while IMF externalizes impacts to countries exporting to China. Modestly increasing feed or food imports in a selective manner could ease the pressure on natural resources. Our modeling framework allows us to analyze the effects of changes in food production-consumption systems in an integrated manner, and the results can be linked to the eight SDGs. Despite formidable technological, social, educational, and structural barriers that need to be overcome, our study indicates that the ambitious targets of China's new agricultural and environmental strategy appear to be achievable.
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http://dx.doi.org/10.1021/acs.est.8b04375DOI Listing
February 2019

China's livestock transition: Driving forces, impacts, and consequences.

Sci Adv 2018 07 18;4(7):eaar8534. Epub 2018 Jul 18.

College of Resources and Environmental Sciences, China Agriculture University, Beijing 100193, China.

China's livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs). Changes were fueled through increases in demand as well as, supply of new breeds, new technology, and government support. Production of animal source protein increased 4.9 times, nitrogen use efficiency at herd level tripled, and average feed use and GHG emissions per gram protein produced decreased by a factor of 2 between 1980 and 2010. In the same period, animal feed imports have increased 49 times, total ammonia and GHG emissions to the atmosphere doubled, and nitrogen losses to watercourses tripled. As a consequence, China's livestock transition has significant global impact. Forecasts for 2050, using the Shared Socio-economic Pathways scenarios, indicate major further changes in livestock production and impacts. On the basis of these possible trajectories, we suggest an alternative transition, which should be implemented by government, processing industries, consumers, and retailers. This new transition is targeted to increase production efficiency and environmental performance at system level, with coupling of crop-livestock production, whole chain manure management, and spatial planning as major components.
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http://dx.doi.org/10.1126/sciadv.aar8534DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6051741PMC
July 2018

Importing food damages domestic environment: Evidence from global soybean trade.

Proc Natl Acad Sci U S A 2018 05 7;115(21):5415-5419. Epub 2018 May 7.

Center for Systems Integration and Sustainability, Michigan State University, East Lansing, MI 48823;

Protecting the environment and enhancing food security are among the world's Sustainable Development Goals and greatest challenges. International food trade is an important mechanism to enhance food security worldwide. Nonetheless, it is widely concluded that in international food trade importing countries gain environmental benefits, while exporting countries suffer environmental problems by using land and other resources to produce food for exports. Our study shows that international food trade can also lead to environmental pollution in importing countries. At the global level, our metaanalysis indicates that there was increased nitrogen (N) pollution after much farmland for domestically cultivated N-fixing soybeans in importing countries was converted to grow high N-demanding crops (wheat, corn, rice, and vegetables). The findings were further verified by an intensive study at the regional level in China, the largest soybean-importing country, where the conversion of soybean lands to corn fields and rice paddies has also led to N pollution. Our study provides a sharp contrast to the conventional wisdom that only exports contribute substantially to environmental woes. Our results suggest the need to evaluate environmental consequences of international trade of all other major goods and products in all importing countries, which have significant implications for fundamental rethinking in global policy-making and debates on environmental responsibilities among consumers, producers, and traders across the world.
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http://dx.doi.org/10.1073/pnas.1718153115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6003527PMC
May 2018

Foxtail Millet [ (L.) Beauv.] Grown under Low Nitrogen Shows a Smaller Root System, Enhanced Biomass Accumulation, and Nitrate Transporter Expression.

Front Plant Sci 2018 22;9:205. Epub 2018 Feb 22.

Key Laboratory of Plant-Soil Interactions, Ministry of Education, Department of Plant Nutrition, China Agricultural University, Beijing, China.

Foxtail millet (FM) [ (L.) Beauv.] is a grain and forage crop well adapted to nutrient-poor soils. To date little is known how FM adapts to low nitrogen (LN) at the morphological, physiological, and molecular levels. Using the FM variety Yugu1, we found that LN led to lower chlorophyll contents and N concentrations, and higher root/shoot and C/N ratios and N utilization efficiencies under hydroponic culture. Importantly, enhanced biomass accumulation in the root under LN was in contrast to a smaller root system, as indicated by significant decreases in total root length; crown root number and length; and lateral root number, length, and density. Enhanced carbon allocation toward the root was rather for significant increases in average diameter of the LN root, potentially favorable for wider xylem vessels or other anatomical alterations facilitating nutrient transport. Lower levels of IAA and CKs were consistent with a smaller root system and higher levels of GA may promote root thickening under LN. Further, up-regulation of SiNRT1.1, SiNRT2.1, and SiNAR2.1 expression and nitrate influx in the root and that of SiNRT1.11 and SiNRT1.12 expression in the shoot probably favored nitrate uptake and remobilization as a whole. Lastly, more soluble proteins accumulated in the N-deficient root likely as a result of increases of N utilization efficiencies. Such "excessive" protein-N was possibly available for shoot delivery. Thus, FM may preferentially transport carbon toward the root facilitating root thickening/nutrient transport and allocate N toward the shoot maximizing photosynthesis/carbon fixation as a primary adaptive strategy to N limitation.
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http://dx.doi.org/10.3389/fpls.2018.00205DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5826958PMC
February 2018

Pursuing sustainable productivity with millions of smallholder farmers.

Nature 2018 03 7;555(7696):363-366. Epub 2018 Mar 7.

Institute of Agricultural Resources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.

Sustainably feeding a growing population is a grand challenge, and one that is particularly difficult in regions that are dominated by smallholder farming. Despite local successes, mobilizing vast smallholder communities with science- and evidence-based management practices to simultaneously address production and pollution problems has been infeasible. Here we report the outcome of concerted efforts in engaging millions of Chinese smallholder farmers to adopt enhanced management practices for greater yield and environmental performance. First, we conducted field trials across China's major agroecological zones to develop locally applicable recommendations using a comprehensive decision-support program. Engaging farmers to adopt those recommendations involved the collaboration of a core network of 1,152 researchers with numerous extension agents and agribusiness personnel. From 2005 to 2015, about 20.9 million farmers in 452 counties adopted enhanced management practices in fields with a total of 37.7 million cumulative hectares over the years. Average yields (maize, rice and wheat) increased by 10.8-11.5%, generating a net grain output of 33 million tonnes (Mt). At the same time, application of nitrogen decreased by 14.7-18.1%, saving 1.2 Mt of nitrogen fertilizers. The increased grain output and decreased nitrogen fertilizer use were equivalent to US$12.2 billion. Estimated reactive nitrogen losses averaged 4.5-4.7 kg nitrogen per Megagram (Mg) with the intervention compared to 6.0-6.4 kg nitrogen per Mg without. Greenhouse gas emissions were 328 kg, 812 kg and 434 kg CO equivalent per Mg of maize, rice and wheat produced, respectively, compared to 422 kg, 941 kg and 549 kg CO equivalent per Mg without the intervention. On the basis of a large-scale survey (8.6 million farmer participants) and scenario analyses, we further demonstrate the potential impacts of implementing the enhanced management practices on China's food security and sustainability outlook.
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http://dx.doi.org/10.1038/nature25785DOI Listing
March 2018

Global environmental costs of China's thirst for milk.

Glob Chang Biol 2018 05 7;24(5):2198-2211. Epub 2018 Feb 7.

College of Resources and Environmental Sciences, China Agriculture University, Beijing, China.

China has an ever-increasing thirst for milk, with a predicted 3.2-fold increase in demand by 2050 compared to the production level in 2010. What are the environmental implications of meeting this demand, and what is the preferred pathway? We addressed these questions by using a nexus approach, to examine the interdependencies of increasing milk consumption in China by 2050 and its global impacts, under different scenarios of domestic milk production and importation. Meeting China's milk demand in a business as usual scenario will increase global dairy-related (China and the leading milk exporting regions) greenhouse gas (GHG) emissions by 35% (from 565 to 764 Tg CO ) and land use for dairy feed production by 32% (from 84 to 111 million ha) compared to 2010, while reactive nitrogen losses from the dairy sector will increase by 48% (from 3.6 to 5.4 Tg nitrogen). Producing all additional milk in China with current technology will greatly increase animal feed import; from 1.9 to 8.5 Tg for concentrates and from 1.0 to 6.2 Tg for forage (alfalfa). In addition, it will increase domestic dairy related GHG emissions by 2.2 times compared to 2010 levels. Importing the extra milk will transfer the environmental burden from China to milk exporting countries; current dairy exporting countries may be unable to produce all additional milk due to physical limitations or environmental preferences/legislation. For example, the farmland area for cattle-feed production in New Zealand would have to increase by more than 57% (1.3 million ha) and that in Europe by more than 39% (15 million ha), while GHG emissions and nitrogen losses would increase roughly proportionally with the increase of farmland in both regions. We propose that a more sustainable dairy future will rely on high milk demanding regions (such as China) improving their domestic milk and feed production efficiencies up to the level of leading milk producing countries. This will decrease the global dairy related GHG emissions and land use by 12% (90 Tg CO reduction) and 30% (34 million ha land reduction) compared to the business as usual scenario, respectively. However, this still represents an increase in total GHG emissions of 19% whereas land use will decrease by 8% when compared with 2010 levels, respectively.
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http://dx.doi.org/10.1111/gcb.14047DOI Listing
May 2018

Cropping System Conversion led to Organic Carbon Change in China's Mollisols Regions.

Sci Rep 2017 12 22;7(1):18064. Epub 2017 Dec 22.

Key Laboratory of Plant-Soil Interactions, Ministry of Education, Center for Resources, Environment, and Food Security, China Agricultural University, Beijing, 100193, China.

Land use change driven by diet, globalization, and technology advancement have greatly influenced agricultural production and environment in the mollisols region of China, with a marked impact on the depletion of soil organic matter, a signature property of mollisols. Here we report findings on soil organic carbon (SOC) change in three different cropping systems (soybean, soybean/maize, corn) in Northeast China during a 10-year time span. The results indicated that the decline rate of SOC in recent ten years (0.27 g kg yr) has slowed down considerably compared to previous decades (1.12 g kg yr). Crop system conversion from soybean monocropping to corn monocropping or break system was the critical factor for SOC change, and the background SOC was the second influence factor. When approaching a SOC turning point, conversion from low carbon input crop system (soybeans monocropping) to high carbon input crop system helped slow down the SOC decline (break crop) or even improve SOC (corn monocropping) in mollisols regions. This result implied that imported soybean has brought benefit for Northeast China. But for sustainable goal in China's mollisols region, straw returning, optimized nitrogen fertilization and no tillage are all necessary whatever in continues maize or rotation system.
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http://dx.doi.org/10.1038/s41598-017-18270-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741738PMC
December 2017
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