Impacts of international food and feed trade on nitrogen balances and nitrogen use efficiencies of food systems.

International trade of agricultural products has greatly increased over time, but its impacts on sustainable development are debated. It may contribute to food security in importing countries, increases the dependency between countries, and has been implicated in displacement of environmental pollution and resource depletion. There is also discussion about the relationships between trade and nitrogen (N) balances and N use efficiencies (NUE). We explored relationships between changes in the trade of food and feed and in N balances and NUE of the food supply systems through simulation modeling and an analysis of empirical data of 115 countries (representing 91% of global population) for the period 1961-2011. In the empirical analysis, 64 main importing countries and 14 main exporting countries, were distinguished. Importing countries had on average a higher population density than exporting countries but rather similar protein intake and GDP per capita. The empirical analysis indicate that main importing countries had on average higher N fertilizer inputs to their food supply systems, and also higher N surpluses and higher NUE than main exporting countries. The overall mean NUE of the food supply system of main importing countries decreased with increasing import, but the relationships between import and NUE were diverse when these countries were grouped according to population density and GDP per capita. We compared N balances and partial N balances, and three methodologies commonly used for estimating NUE. We observed that NUE2 provides an unbiased estimate for both importing and exporting countries. Our study contributes to the understanding of the diverse relationships between international trade, N balances and NUE of food systems.

Nutrient use efficiencies, losses, and abatement strategies for peri-urban dairy production systems.

Manure management is an important aspect of urban livestock production that has a profound impact on metropolitan living. Data were collected from 28 dairy farms in peri-urban Beijing and analysed to determine farm nitrogen and phosphorus flows and costs associated with various manure management options to reduce nutrient losses. Dairy production in peri-urban Beijing was characterized by its use of high protein diets (16.3-17.0% crude protein), high reliance on imported feeds (92-98%), and low manure recycling (3.0-10.8%). Farms of 900-2000 cattle showed lower use efficiencies than farms of <900 cattle. Costs of manure handling ranged from 0.1 to 1.0 Yuan kg-1 milk. Among various manure treatment options, biogas digesters with aerobic lagoons had the lowest N losses and costs, justifying their investments. In conclusion, peri-urban dairy production systems were contrasting with traditional systems and within their own systems in nutrient use efficiency and losses, which was mainly decided by their farm size. To improve the nutrient use efficiencies and reduce losses, farmers and managers of peri-urban dairy production system should have a full awareness of different feed intake and manure management.

Mitigating ammonia emission from agriculture reduces PM2.5 pollution in the Hai River Basin in China.

The Hai River Basin (HRB), one of the most populated areas in China, is experiencing high NH3 emissions, mostly from agricultural sources, and suffering from strongly enhanced PM2.5 concentrations in all urban areas. Further population growth and urbanization projected until 2030 may exacerbate this situation. Here, the NUFER (NUtrient flows in Food chains, Environment and Resources use) and GAINS (Greenhouse gas - Air pollution Interactions and Synergies) models have been coupled for the first time to understand possible changes of agricultural NH3 emission between 2012 and 2030 and their impacts on ambient PM2.5 concentrations, and to explore options to improve this situation. Results show that agricultural ammonia emissions in the HRB were 1179kt NH3 in 2012, 45% of which was from the hotspots at or near conurbation areas, including Beijing-Tianjin, Tangshan-Qinhuangdao, Shijiazhuang-Baoding, Dezhou, Handan-Liaocheng, and Xinxiang. Without intervention, agricultural ammonia emissions will further increase by 33% by 2030. The impacts of several scenarios were tested with respect to air pollution. Compared to the business-as-usual scenario, a scenario of improved technology and management combined with human diet optimization could greatly reduce emission (by 60%), and lead to 22-43% and 9-24% decrease of the secondary inorganic aerosols and PM2.5 concentrations, respectively, in the hotspots of NH3 emissions. Our results further confirmed that ammonia control is needed for air pollution abatement strategies (SO2, NOx and primary PM reduction) to be effective in terms of PM2.5.

Changes in pig production in China and their effects on nitrogen and phosphorus use and losses.

China's pig production has increased manifold in the past 50 years, and this has greatly affected the nitrogen and phosphorus use and losses in the pig production sector. However, the magnitude of these changes are not well-known. Here, we provide an in-depth account of the changes in pig production--N and P use and total N and P losses in the whole pig production chain during the period 1960-2010--through simulation modeling and using data from national statistics and farm surveys. For the period of 2010-2030, we explored possible effects of technological and managerial measures aimed at improving the performances of pig production via scenario analysis. We used and further developed the NUtrient flows in Food chains, Environment and Resources use (NUFER) model to calculate the feed requirement and consumption, and N and P losses in different pig production systems for all the years. Between 1960 and 2010, pig production has largely shifted from the so-called backyard system to landless systems. The N use efficiencies at fattener level increased from 18 to 28%, due to the increased animal productivity. However, the N use efficiencies at the whole-system level decreased from 46 to 11% during this period, mainly due to the increase of landless pig farms, which rely on imported feed and have no land-base for manure disposal. The total N and P losses were 5289 and 829 Gg in 2010, which is 30 and 95 times higher than in 1960. In the business as usual scenario, the total N and P losses were projected to increase by 25 and 55% between 2010 and 2030, respectively. Analyses of other scenarios indicate that packages of technological and managerial measures can decrease total N and P losses by 64 and 95%, respectively. Such improvements require major transition in the pig production sector, notably, in manure management, herd management, and feeding practices.

Prognostic and assessment value of hyperglycemia and glycosylated hemoglobin in critical patients.

Hyperglycemia is common in critical patients and high blood glucose levels have a negative effect on their prognosis. The aim of this study was to investigate the effect of hyperglycemia and glycosylated hemoglobin (GHb) in critical patients. A total of 648 critical patients were enrolled in the study and received a random blood glucose test when they entered the emergency department. If blood glucose was more than 11.1 mM, a GHb test was followed within 24 h. All patients were followed up for 28 days. According to diabetes mellitus (DM) history, GHb value, and outcome of follow-up, patients were divided into different groups, and mortality rates were calculated, respectively. Hyperglycemia was found in 67.44% (437/648) of patients, and 51.49% (225/437) and 48.51% (212/437) had normal and elevated GHb levels, respectively. At the end of the follow-up period, 14 of the normal GHb patients and 32 of the elevated GHb patients died (6.22 and 15.09%, respectively). In the normal GHb group, 53 had a DM history, 23 were newly diagnosed with DM, and 149 had hospital-related hyperglycemia (HRH); the mortality rates were 11.32% (6/53), 8.70% (2/23), and 4.03% (6/149), respectively. In the elevated GHb group, 114 had a DM history, 83 were newly diagnosed with DM, and 15 had HRH; the mortality rates were 13.16% (15/114), 19.27% (16/83), and 6.67% (1/15), respectively. Hyperglycemia and GHb might play important roles in the prognosis and assessment for critical patients, and the prognosis would vary according to the different causes of hyperglycemia.

Nitrogen and phosphorus use efficiencies in dairy production in china.

Milk production has greatly increased in China recently, with significant impacts on the cycling of nitrogen (N) and phosphorus (P). However, nutrient flows within the changing dairy production system are not well quantified. The aim of this study was to increase the quantitative understanding of N and P cycling and utilization in dairy production through database development and simulation modeling. In 2010, of the entire 1987 and 346 thousand tons (Gg) of N and P input, only 188 Gg N and 31 Gg P ended up in milk. The average N and P use efficiencies were 24 and 25%, respectively, at the whole system level. Efficiencies differed significantly between the four dairy systems. Losses of N from these systems occurred via NH volatilization (33%), discharge (27%), denitrification (24%), NO leaching and runoff (16%), and NO emission (1%). Industrial feedlots use less feed per kg milk produced than traditional systems, and rely more on high-quality feed from fertilized cropland; they have very poor recycling of manure nutrients to cropland. As industrial feedlot systems are booming, overall mean N and P use efficiencies will increase at herd level but will decrease at the whole dairy production system level unless manure N and P are used more efficiently through reconnecting China's feed and dairy production sectors.

Pectinase production by Aspergillus niger using wastewater in solid state fermentation for eliciting plant disease resistance.

An elicitor of plant disease resistance, pectinase, was produced by solid state fermentation with Aspergillus niger. Sugar beet pulp was used as carbon source and the wastewater from monosodium glutamate production was used as nitrogen and water source. The composition of the fermentation medium was: 11 ml concentrated wastewater (containing NH3-N 38.2 mg/ml), sugar beet pulp 10 g, Na2HPO4.12H2O 0.2 g, KH2PO4 0.04 g in a 500 ml Erlenmeyer flask. The fermentation temperature was 30 degrees C and the relative humidity of the air was 75-90%. The maximum production of pectinase was reached after 96 h cultivation. The crude pectinase extracted from the fermented materials could elicit disease resistance in cucumber and tomato seedlings.