Sustainable Blue Foods from Rice-Animal Coculture Systems.

Global interest grows in blue foods as part of sustainable diets, but little is known about the potential and environmental performance of blue foods from rice-animal coculture systems. Here, we compiled a large experimental database and conducted a comprehensive life cycle assessment to estimate the impacts of scaling up rice-fish and rice-crayfish systems in China. We find that a large amount of protein can be produced from the coculture systems, equivalent to ∼20% of freshwater aquaculture and ∼70% of marine wild capture projected in 2030.

Ecosystem multifunctionality and soil microbial communities in response to ecological restoration in an alpine degraded grassland.

Linkages between microbial communities and multiple ecosystem functions are context-dependent. However, the impacts of different restoration measures on microbial communities and ecosystem functioning remain unclear. Here, a 14-year long-term experiment was conducted using three restoration modes: planting mixed grasses (MG), planting shrub with alone (SA), and planting shrub with plus planting mixed grasses (SG), with an extremely degraded grassland serving as the control (CK).

Linking between soil properties, bacterial communities, enzyme activities, and soil organic carbon mineralization under ecological restoration in an alpine degraded grassland.

Soil organic carbon (SOC) mineralization is affected by ecological restoration and plays an important role in the soil C cycle. However, the mechanism of ecological restoration on SOC mineralization remains unclear. Here, we collected soils from the degraded grassland that have undergone 14 years of ecological restoration by planting shrubs with alone (SA) and, planting shrubs with plus planting mixed grasses (SG), with the extremely degraded grassland underwent natural restoration as control (CK).

Integrated biochar solutions can achieve carbon-neutral staple crop production.

Agricultural food production is a main driver of global greenhouse gas emissions, with unclear pathways towards carbon neutrality. Here, through a comprehensive life-cycle assessment using data from China, we show that an integrated biomass pyrolysis and electricity generation system coupled with commonly applied methane and nitrogen mitigation measures can help reduce staple crops' life-cycle greenhouse gas emissions from the current 666.5 to -37.

Organic amendments enhance soil microbial diversity, microbial functionality and crop yields: A meta-analysis.

Fertilization plays an important role in changing soil microbial diversity, which is essential for determining crop yields. Yet, the influence of organic amendments on microbial diversity remains uncertain, and few studies have addressed the relative importance of microbial diversity versus other drivers of crop yields. Here, we synthesize 219 studies worldwide and found that organic amendments significantly increased microbial diversity components (i.

Deceleration of Cropland-NO Emissions in China and Future Mitigation Potentials.

Agricultural soils are the largest anthropogenic emission source of nitrous oxide (NO). National agricultural policies have been implemented to increase crop yield and reduce nitrogen (N) losses to the environment. However, it is difficult to effectively quantify crop-specific and regional NO mitigation priorities driven by policies, due to lack of long-term, high-resolution crop-specific activity data, and oversimplified models.

Elevated CO does not necessarily enhance greenhouse gas emissions from rice paddies.

Elevated atmospheric carbon dioxide (eCO) greatly impacts greenhouse gas (GHG) emissions of CH and NO from rice fields. Although eCO generally stimulates GHG emissions in the short term (<5 years) experiments, the responses to long-term (≥10 years) eCO remain poorly known. Here we show, through a series of experiments and meta-analysis, that the eCO does not necessarily increase CH and NO emissions from rice paddies.

Role of chemical reactions in the nitrogenous trace gas emissions and nitrogen retention: A meta-analysis.

Increasing evidence has been found that chemical reactions affect significantly the terrestrial nitrogen (N) cycle, which was previously assumed to be mainly dominated by biological processes. Due to the limitation of knowledge and analytical techniques, it is currently challenging to discern the contribution of biotic and abiotic processes to the terrestrial N cycle for geobiologists and biogeochemists alike. To better understand the role of abiotic reactions in the terrestrial N cycle, it is necessary to comprehend the chemical controls on nitrogenous trace gas emissions and N retention in soil under various environmental conditions.

Temporal and spatial variations in nitrogen use efficiency of crop production in China.

The low value of nitrogen use efficiency (NUE) (around 30%) of crop production in China highlights the necessity to adopt reasonable N managements in national scale. After the implementation of 'National Soil Testing and Formulated Fertilization' program in 2005, many field experiments have reported an increase of NUE for crop productions in China. This has prompted discussion regarding the extent to which NUE in crop production has been improved.

Environmental and economic trade-offs of using composted or stockpiled manure as partial substitute for synthetic fertilizer.

Manure generated from livestock production could represent an important source of plant nutrients in substitution of synthetic fertilizer. To evaluate the sustainability of partially substituting synthetic fertilizer with soil organic amendments (OAs) in horticulture, an economic and greenhouse gas (GHG) budget was developed. The boundary for analysis included manure processing (stockpiling vs.

Anaerobic soil disinfestation with incorporation of straw and manure significantly increases greenhouse gases emission and reduces nitrate leaching while increasing leaching of dissolved organic N.

Greenhouse vegetable production in China mostly involves excessive N fertilization and flood irrigation. This causes serious soil degradation and spreading of soil borne diseases. As a countermeasure against soil borne diseases anaerobic soil disinfestation (ASD) is applied during the summer fallow period.

Drip fertigation with straw incorporation significantly reduces NO emission and N leaching while maintaining high vegetable yields in solar greenhouse production.

Approximately 1/3 of vegetables in China are produced in solar greenhouses. Most farmers use conventional irrigation with over fertilisation (CIF), thereby applying approximately 2000 kg N ha fertiliser over two cropping seasons per year. Here, we tested the effect of drip irrigation with reduced fertilisation (DIF) combined with straw incorporation on reducing NO emissions and nitrogen leaching from solar greenhouse vegetable production systems.

Measurement of NO emissions over the whole year is necessary for estimating reliable emission factors.

Nitrous oxide emission factors (NO-EF, percentage of NO-N emissions arising from applied fertilizer N) for cropland emission inventories can vary with agricultural management, soil properties and climate conditions. Establishing a regionally-specific EF usually requires the measurement of a whole year of NO emissions, whereas most studies measure NO emissions only during the crop growing season, neglecting emissions during non-growing periods. However, the difference in NO-EF (ΔEF) estimated using measurements over a whole year (EF) and those based on measurement only during the crop-growing season (EF) has received little attention.

Simultaneous quantification of N , NH and N O emissions from a flooded paddy field under different N fertilization regimes.

Gaseous nitrogen (N) emissions, especially emissions of dinitrogen (N ) and ammonia (NH ), have long been considered as the major pathways of N loss from flooded rice paddies. However, no studies have simultaneously evaluated the overall response of gaseous N losses to improved N fertilization practices due to the difficulties to directly measure N emissions from paddy soils. We simultaneously quantified emissions of N (using membrane inlet mass spectrometry), NH and nitrous oxide (N O) from a flooded paddy field in southern China over an entire rice-growing season.

Potential for mitigating global agricultural ammonia emission: A meta-analysis.

Ammonia (NH) emission from agricultural sources has contributed significantly to air pollution, soil acidification, water eutrophication, biodiversity loss, and declining human health. Although there are numerous strategies for reducing NH emission from agricultural systems, the effectiveness of these measures is highly variable. Furthermore, the integrated assessment of measures to reduce NH emission both from livestock production and cropping systems based on animal and crop type is lacking.

Trade-offs between soil carbon sequestration and reactive nitrogen losses under straw return in global agroecosystems.

It is widely recommended that crop straw be returned to croplands to maintain or increase soil carbon (C) storage in arable soils. However, because C and nitrogen (N) biogeochemical cycles are closely coupled, straw return may also affect soil reactive N (Nr) losses, but these effects remain uncertain, especially in terms of the interactions between soil C sequestration and Nr losses under straw addition. Here, we conducted a global meta-analysis using 363 publications to assess the overall effects of straw return on soil Nr losses, C sequestration and crop productivity in agroecosystems.

Measurement of N2, N2O, NO, and CO2 emissions from soil with the gas-flow-soil-core technique.

Here we describe a newly designed system with three stand-alone working incubation vessels for simultaneous measurements of N(2), N(2)O, NO, and CO(2) emissions from soil. Due to the use of a new micro thermal conductivity detector and the redesign of vessels and gas sampling a so-far unmatched sensitivity (0.23 μg N(2)-N h(-1) kg(-1) ds or 8.

Isoprene emission protects photosynthesis in sunfleck exposed Grey poplar.

In the present study, we combined transient temperature and light stress (sunfleck) and comparably analyzed photosynthetic gas exchange in Grey poplar which has been genetically modified in isoprene emission capacity. Overall, we demonstrate that for poplar leaves the ability to emit isoprene is crucial to maintain photosynthesis when exposed to sunflecks. Net CO2 assimilation and electron transport rates were strongly impaired in sunfleck-treated non-isoprene emitting poplars.

Transgenic, non-isoprene emitting poplars don't like it hot.

The physiological role of isoprene emission in plants is a matter of much debate. One of the most widely propagated hypotheses suggests a function of isoprene in the protection of leaf physiological processes against thermal and oxidative stress. To test this hypothesis, we developed transgenic Grey poplar (Populusxcanescens) plants in which gene expression of isoprene synthase (ISPS) was either silenced by RNA interference (RNAi) or upregulated by over-expression of the ISPS gene.

Sensitivity of volatile monoterpene emission to changes in canopy structure: a model-based exercise with a process-based emission model.

This paper investigates the dependence of monoterpene emissions at the canopy scale on total leaf area and leaf distribution. Simulations were carried out for a range of hypothetical but realistic forest canopies of the evergreen Quercus ilex (holm oak). Two emission models were applied that either did (SIM-BIM2) or did not (G93) account for cumulative responses to temperature and light.