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. composting) and transport and spreading of manure and compost (feedlot and chicken) in intensively cultivated horticultural fields. The OA field application rates were calculated based on the nitrogen supplied by OAs. The GHG budget based on directly measured emissions indicates that the application of composted manure, in combination with reduced fertilizer rate, was always superior to stockpiled manures. Compost treatments showed from 9 to 90% less GHG emissions than stockpiled manure treatments. However, higher costs associated with the purchase and transport of composted manure (three times higher) generated a greater economic burden compared with stockpiled manure and synthetic fertilizer application. The plant nutrient replacement value of the OAs was considered only for the first year of application, and if long-term nutrient release from OAs is taken into account, additional savings are possible. Because the income from soil carbon sequestration initiatives in response to OA application is unlikely to bridge this financial gap, particularly in the short term, this study proposes that future policy should develop methodologies for avoided GHG emissions from OA application. The combined income from soil carbon sequestration and potentially avoided GHG initiatives could incentivize farmers to adopt OAs as a substitute for synthetic fertilizers, thereby promoting more sustainable farming practices.</p

Measuring denitrification and the N2_{2}O:(N2_{2}O + N2_{2}) emission ratio from terrestrial soils

Denitrification, a significant pathway of reactive N-loss from terrestrial soils, impacts on agricultural production and the environment. Net production and emission of the denitrification product nitrous oxide (N$_{2}$O) is readily quantifiable, but measuring denitrification\u27s final product, dinitrogen (N$_{2}$), against a high atmospheric background remains challenging. This review examines methods quantifying both N$_{2}$ and N$_{2}$O emissions, based on inhibitors, helium/O$_{2}$ atmosphere exchange, and isotopes. These methods are evaluated regarding their capability to account for pathways of N$_{2}$ and N$_{2}$O production and we suggest quality parameters for measuring denitrification from controlled environments to the field scale. Our appraisal shows that method combinations, together with real-time monitoring and soil-gas diffusivity modelling, have the potential to significantly improve our quantitative understanding for denitrification from upland soils. Requirements for instrumentation and experimental setups however highlight the need to develop more mobile and easily accessible field methods to constrain denitrification from terrestrial soils across scales

Strategies for mitigating N2O and N2 emissions from an intensive sugarcane cropping system

In sugarcane cropping systems, high rates of N fertiliser are typically applied as sub-surface bands creating localised zones of high mineral N concentrations. This in combination with high levels of crop residue (trash) retention and a warm and humid climate creates conditions that are known to promote soil denitrification, resulting in high emissions of the potent greenhouse gas N2O. These losses illustrate inefficient use of N fertilisers but total denitrification losses in the form of N2 and N2O remain largely unknown. We used the 15N gas flux method to investigate the effect of cane trash removal and the use of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N2 and N2O emissions on a commercial sugarcane farm at Bundaberg, Australia. High gaseous N losses were observed under the standard grower practice where cane trash retention and N fertiliser application (145 kg N ha−1 as urea) resulted in N2 and N2O emissions (36.1 kg N ha−1) from the subsurface N fertiliser band, with more than 50% of these losses emitted as N2O. Cane trash removal reduced N2 emission by 34% and N2O emission by 51%, but had no effect on the N2O/(N2 + N2O) ratio. The use of DMPP lowered N2 and N2O emission by 35% and 98%, respectively, reducing the percentage of these losses (N2 + N2O) emitted as N2O to only 4%. We conclude that the use of DMPP is an effective strategy to reduce N losses, minimise N2O emissions, while keeping the benefits of cane trash retention in sugarcane cropping systems.</p

Production and Properties of Lignin Nanoparticles from Ethanol Organosolv Liquors-Influence of Origin and Pretreatment Conditions

Despite major efforts in recent years, lignin as an abundant biopolymer is still underutilized in material applications. The production of lignin nanoparticles with improved properties through a high specific surface area enables easier applicability and higher value applications. Current precipitation processes often show poor yields, as a portion of the lignin stays in solution. In the present work, lignin was extracted from wheat straw, spruce, and beech using ethanol organosolv pretreatment at temperatures from 160–220 °C. The resulting extracts were standardized to the lowest lignin content and precipitated by solvent-shifting to produce lignin micro- and nanoparticles with mean hydrodynamic diameters from 67.8 to 1156.4 nm. Extracts, particles and supernatant were analyzed on molecular weight, revealing that large lignin molecules are precipitated while small lignin molecules stay in solution. The particles were purified by dialysis and characterized on their color and antioxidant activity, reaching ASC equivalents between 19.1 and 50.4 mg/mg. This work gives detailed insight into the precipitation process with respect to different raw materials and pretreatment severities, enabling better understanding and optimization of lignin nanoparticle precipitation

Magnetically assisted processing of a medium.

The invention relates to a processing device(100) and a method for processing a medium in a processing chamber(121). The processing comprises the addition of magnetic particles(M) to the medium and the mixing of the medium by manipulating said magnetic particles with a time-variable magnetic field(B), particularly a partially oscillating or rotating field. The magnetic field(B) may be generated with a multipole magnetic field generator(110) comprising four subunits(111A,111B), each having a core(113A,113B) with a surrounding coil(112A,112B) and with a top surface(114A,114B), wherein all top surfaces of said subunits are preferably arranged in the same plane and wherein all cores are substantially parallel to each other