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Corn ( Zea mays L.) residue removal at high rates can result in negative impacts to soil ecosystem services. The use of cover crops could be a potential strategy to ameliorate any adverse effects of residue removal while allowing greater removal levels. Hence, the objective of this study was to determine changes in water erosion potential, soil organic C (SOC) and total N concentration, and crop yields under early- and late-terminated cover crop (CC) combined with five levels of corn residue removal after 3 years on rainfed and irrigated no-till continuous corn in Nebraska. Treatments were no CC, early- and late-terminated winter rye ( Secale cereale L.) CC, and 0, 25, 50, 75, and 100% corn residue removal rates. Complete residue removal reduced mean weight diameter (MWD) of water-stable aggregates (5 cm depth) by 29% compared to no removal at the rainfed site only, suggesting increased water erosion risk at rainfed sites. Late-terminated CC significantly increased MWD of water-stable aggregates by 27 to 37% at both sites compared to no CC, but early-terminated CC had no effect. The increased MWD with late-terminated CC suggests that CC when terminated late can offset residue removal-induced risks of water erosion. Residue removal and CC did not affect SOC and total soil N concentration. Particulate organic matter increased with late-terminated CC at the irrigated site compared to no CC. Complete residue removal increased irrigated grain yield by 9% in 1 year relative to no removal. Late-terminated CC had no effect on corn yield except in 1 year when yield was 8% lower relative to no CC due to low precipitation at corn establishment. Overall, late-terminated CC ameliorates residue removal-induced increases in water erosion potential and could allow greater levels of removal without reducing corn yields in most years, in the short term, under the conditions of this study. [ABSTRACT FROM AUTHOR]

The objective of this 2-yr study was to evaluate growing and finishing performance as well as carcass characteristics of spring-born steers backgrounded on 3 different systems, using feedstuffs readily available in the Midwest: 1) grazing corn residue and being supplemented with dried distillers plus solubles at 2.68 kg DM/steer 6 d/wk (RESIDUE), 2) grazing a late summer-planted oat-brassica forage mix (CCROP), or 3) being fed a corn silage-based diet in a drylot (DRYLOT). Steers (n = 715) were stratified by BW (278 kg ± 23 in yr 1 and 291 kg ± 91 in yr 2) and assigned to treatment and replicate (4 replications per treatment per yr). Steers assigned to DRYLOT were fed a corn silage-based diet for 54 d in yr 1 and 52 d in yr 2 before being transitioned to the finishing diet. Steers assigned to RESIDUE and those assigned to CCROP grazed 65 d in yr 1 and 66 d in yr 2 and then were fed a corn silage-based diet for 21 d in yr 1 and 33 d in yr 2 before being transitioned to the finishing diet. During backgrounding, the ADG (SEM 0.022) of steers assigned to DRYLOT (1.48 kg/d) was greater (P < 0.01) than that of steers assigned to both CCROP (1.05 kg/d) and RESIDUE (0.87 kg/d) and ADG of steers assigned to CCROP was greater (P < 0.01) than that of steers assigned to RESIDUE. At the start of the finishing period, BW of steers assigned to CCROP (381 kg) was greater (P < 0.01, SEM 2.5) than that of steers assigned to DRYLOT (361 kg) and RESIDUE (366 kg). The finishing period lasted 160 d for all treatments. Both 12th-rib fat (P = 0.89) and calculated yield grade (P = 0.39) did not differ among treatments. Finishing G:F of steers assigned to DRYLOT (0.162 kg/kg) was greater (P < 0.01, SEM 0.0015) than that of steers assigned to RESIDUE (0.153 kg/kg) and CCROP (0.153 kg/kg), which did not differ (P = 0.79). In yr 1, HCW of steers assigned to CCROP (402 kg) was greater (P < 0.01, SEM 2.1) than that of steers assigned to both RESIDUE (389 kg) and DRYLOT (391 kg), which did not differ (P = 0.40). This difference in HCW is most likely a result of differences in BW at the start of the finishing phase in yr 1. However in yr 2, HCW of steers assigned to CCROP (400 kg) and RESIDUE (397 kg) did not differ (P = 0.26, SEM 2.1) but were greater (P < 0.01) than that of steers assigned to DRYLOT (367 kg), despite the fact that steers assigned to RESIDUE entered the finishing phase at a lighter BW than steers assigned to CCROP. Marbling was greater (P = 0.01, SEM 3.9) for steers assigned to DRYLOT (429) than for steers assigned to RESIDUE (414), although steers assigned to CCROP (424) were not different (P ≥ 0.10) from steers assigned to DRYLOT or RESIDUE. When cost and price scenarios from the last 5 yr were conducted, no treatment appeared to be consistently superior in terms of cost of gain or net return. Therefore, all 3 systems appear to be viable options for producers. [ABSTRACT FROM AUTHOR]

Two experiments evaluated the effects of corn residue harvest method on animal performance and diet digestibility. Experiment 1 was designed as a 2 × 2 + 1 factorial arrangement of treatments using 60 individually fed crossbred steers (280 kg [SD 32] initial BW; n = 12). Factors were the corn residue harvest method (high-stem and conventional) and supplemental RUP at 2 concentrations (0 and 3.3% diet DM). A third harvest method (low-stem) was also evaluated, but only in diets containing supplemental RUP at 3.3% diet DM because of limitations in the amount of available low-stem residue. Therefore, the 3 harvest methods were compared only in diets containing supplemental RUP. In Exp. 2, 9 crossbred wethers were blocked by BW (42.4 kg [SD 7] initial BW) and randomly assigned to diets containing corn residue harvested 1 of 3 ways (low-stem, high-stem, and conventional). In Exp. 1, steers fed the lowstem residue diet had greater ADG compared with the steers fed conventionally harvested corn residue (P = 0.03; 0.78 vs. 0.63 kg), whereas steers fed highstem residue were intermediate (P > 0.17; 0.69 kg), not differing from either conventional or low-stem residues. Results from in vitro OM digestibility suggest that low-stem residue had the greatest (P < 0.01) amount of digestible OM compared with the other 2 residue harvest methods, which did not differ (P = 0.32; 55.0, 47.8, and 47.1% for low-stem, high-stem, and conventional residues, respectively). There were no differences in RUP content (40% of CP) and RUP digestibility (60%) among the 3 residues (P ≥ 0.35). No interactions were observed between harvest method and the addition of RUP (P ≥ 0.12). The addition of RUP tended to result in improved ADG (0.66 ± 0.07 vs. 0.58 ± 0.07 for supplemental RUP and no RUP, respectively; P = 0.08) and G:F (0.116 ± 0.006 vs. 0.095 ± 0.020 for supplemental RUP and no RUP, respectively; P = 0.02) compared with similar diets without the additional RUP. In Exp. 2, low-stem residue had greater DM and OM digestibility and DE (P < 0.01) than high-stem and conventional residues, which did not differ (P ≥ 0.63). Low-stem residue also had the greatest NDF digestibility (NDFD; P < 0.01), whereas high-stem residue had greater NDFD than conventional residue (P < 0.01). Digestible energy was greatest for low-stem residue (P < 0.05) and did not differ between high-stem and conventional residues (P = 0.50). Reducing the proportion of stem in the bale through changes in the harvest method increased the nutritive quality of corn residue. [ABSTRACT FROM AUTHOR]

We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25 FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5 mg/g and gave 98% cellulose conversion in 72 h. However, for double the amount of enzyme from Trichoderma reesei , which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger ) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. [ABSTRACT FROM AUTHOR]

• This study provides a method-based NIR spectra to detect pesticide residue in corn oil. • Data augmentation algorithms were employed to effectively expand the database. • One-dimensional convolutional neural networks were designed for model calibration. • This study used NIR spectral deep learning model to analyze the pesticide residues in edible oil. This study introduces a fast analytical approach for detecting chlorpyrifos residues in corn oil, based on a one-dimensional convolutional neural network (1D-CNN) structure for near-infrared (NIR) spectral deep learning models. Data augmentation algorithms were introduced to effectively expand the database of corn oil samples obtained in the experiment, ensuring sufficient training of the deep learning network. A well-designed 1D-CNN structure was implemented to create a multivariate calibration model. This model can be used to quantify chlorpyrifos residues in corn oil. The study found that using data augmentation with a 1D-CNN model led to improved performance compared to using the original spectra calibration in the model. Particularly, the 1D-CNN model's best overall performance was achieved using data augmented with varying degrees of signal-to-noise ratio (SNR) algorithms, with a prediction coefficient of determination (R P 2) of 0.9492 and a relative percent deviation (RPD) of 4.4569. The study demonstrates the feasibility of using NIR spectral deep learning models for quantitative analysis of pesticide residues in edible oils. Furthermore, data augmentation methods can effectively improve the accuracy of deep learning algorithms in NIR spectral chemometrics model calibration. [ABSTRACT FROM AUTHOR]

This paper presents the results of the evaluation of the energy potential of waste from the process of drying corn grain in the form of corn cobs, damaged grains, corn grain husks, and mixtures of starting materials. A technical and elementary analysis was performed for the biomass under investigation. The elemental composition of ash and the tendencies for slagging and boiler slagging were determined, and the emission factors were estimated based on the elemental analysis performed. The tests showed the highest calorific value among the starting materials for corn cobs (CCs) (14.94 MJ·kg−1) and for the mixture of corn cobs with corn husk (CC−CH) (13.70 MJ·kg−1). The estimated emission factors were within ranges of 38.26−63.26 kg·Mg−1 for CO, 936−1549 kg·Mg−1 for CO2, 0.85−4.32 kg·Mg−1 for NOx, 0.91−1.03 kg·Mg−1 for SO2, and 3.88−54.31 kg·Mg−1 for dust. The research showed that the creation of mixtures from starting materials leads to materials with lower potential for negative environmental impact as well as a reduced risk of slagging and fouling of biomass boilers. However, taking into account all the parameters determined for the biomass under study, the highest energy potential was characteristic for corn cobs and the mixture of corn cobs with corn husk.

Nowadays raw empty corn cobs have been used as substitute fuel in conventional boilers in corn mills, in which the thermal efficiency is low because of its poor fuel properties. The fuel property of empty cobs can be improved by torrefaction process. This study focuses on the in-depth study of the gasification process using raw empty cobs and torrefied empty cobs as solid fuel. The gasification process was carried out in a batch-type laboratory scale downdraft gasifier at the air flow rate of 250 liters per minute for raw empty cobs, and 250, 300, and 350 liters per minute for torrefied empty cobs. The temperature distribution in each reaction zone, the producer gas composition, the heating value of the producer gas, and finally the cold gas efficiency obtained from the gasification of the raw empty cobs and terrified empty cobs were compared. The experimental results showed that the gasification of the torrefied empty cobs can provide better gasification behavior than raw empty cobs. The temperature in each reaction zone was higher for torrefied empty cobs, which ranged from 846.5°C to1,291.6°C in the combustion zone, and from 720.1°C to 838.8°C in the reduction zone, whereas the temperature in the combustion zone and reduction zone in the case of using raw empty cobs varied from 715.5°C to 909.7°C and 709.9°C to 814.5°C. Furthermore, the temperature distribution along the height of the gasifier was more stable for the torrefied empty cobs. The producer gas obtained from the gasification of the raw empty cobs contained more CO (18.20-27.79 %-vol.), H 2 (3.63-9.37 %-vol.) and CH 4 (0.17-0.33 %-vol.), but less CO 2 , O 2 , and N 2 than that obtained from the terrified empty cobs, which contained 5.72 %-vol. CO, 0.97 %-vol. H 2 and 0.03 %-vol. CH 4 . The higher CO, H 2 , and CH 4 led to a higher heating value for the producer gas and cold gas efficiency for the torrefied empty cobs. The producer gas heating value increased from 0.835 MJ/Nm 3 for the raw empty cobs to 2.84-4.25 MJ/Nm 3 for the torrefied empty cobs, and the cold gas efficiency increased from 31% for the raw empty cobs to 55-87% for the torrefied empty cobs. [ABSTRACT FROM AUTHOR]

Pyrolysis of corn stalk residue (CSR) and cassava rhizome residue (CRR) to produce bio-oil were investigated using a fluidized bed reactor. Both feedstocks possessed low volatile matters and high ash contents. The results showed that the bio-oil yield of CSR reached the highest value (25.1%) at 700 °C, while that of CRR peaked (30.6%) at 600 °C. The obtained bio-oils were separated into light fraction and heavy fraction automatically. The light fraction mainly consisted of furan compounds and carboxylic acids, while the heavy fraction mainly consisted of aromatic compounds. Due to the abundant lignin in the residues, high heating values (HHVs) of the heavy fractions reached 25.5–26.8 MJ/kg which were significantly higher than typical bio-oils. [ABSTRACT FROM AUTHOR]

The cellulolytic Clostridium cellulovorans has been engineered to produce n -butanol from low-value lignocellulosic biomass by consolidated bioprocessing (CBP). The objective of this study was to establish a robust cellulosic biobutanol production process using a metabolically engineered C. cellulovorans . First, various methods for the pretreatment of four different corn-based residues, including corn cob, corn husk, corn fiber, and corn bran, were investigated. The results showed that better cell growth and a higher concentration of n -butanol were produced from corn cob that was pretreated with sodium hydroxide. Second, the effects of different carbon sources (glucose, cellulose and corn cob), basal media and culture pH values on butanol production were evaluated in the fermentations performed in 2-L bioreactors to identify the optimal CBP conditions. Finally, the engineered C. cellulovorans produced butanol with final concentration >3 g/L, yield >0.14 g/g, and selectivity >3 g/g from pretreated corn cob at pH 6.5 in CBP. This study showed that the fermentation process engineering of C. cellulovorans enabled a high butanol production directly from agricultural residues. [ABSTRACT FROM AUTHOR]

Reflectance indices are a method for reducing the dimensionality of spectral measurements used to quantify material properties. Choosing the optimal wavelengths for developing an index based on a given material and property of interest is made difficult by the large number of wavelengths typically available to choose from and the lack of homogeneity when remotely sensing agricultural materials. This study aimed to determine the feasibility of using a low-cost method for sensing the moisture content of background materials in traditional crop remote sensing. Moisture-controlled soil and wheat stalk residue samples were measured at varying heights using a reflectance probe connected to visible and near-infrared spectrometers. A program was written that used reflectance data to determine the optimal pair of narrowband wavelengths to calculate a normalized difference water index (NDWI). Wavelengths were selected to maximize the slope of the linear index function (i.e., sensitivity to moisture) and either maximize the coefficient of determination (R2) or minimize the root mean squared error (RMSE) of the index. Results showed that wavelengths centered near 1300 nm and 1500 nm, within the range of 400 to 1700 nm, produced the best index for individual samples. Probe height above samples and moisture content were examined for statistical significance using the selected wavelengths. The effect of moisture was significant for both bare soil and wheat stalks, but probe height was only significant for wheat stalk samples. The index, when applied to all samples, performed well for soil samples but poorly for wheat stalk samples. Index calculations from soil reflectance measurements were highly linear (R² > 0.95) and exhibited small variability between samples at a given moisture content, regardless of probe height. Index calculations from wheat stalk reflectance measurements were highly variable, which limited the usefulness of the index for this material. Based on these results, it is expected that crop residues, such as wheat stalks, will reduce the accuracy of remotely sensed soil surface moisture measurements. [ABSTRACT FROM AUTHOR]

Removal of corn ( Zea mays L.) residues at high rates for biofuel and other off-farm uses may negatively impact soil and the environment in the long term. Biomass removal from perennial warm-season grasses ( WSGs) grown in marginally productive lands could be an alternative to corn residue removal as biofuel feedstocks while controlling water and wind erosion, sequestering carbon (C), cycling water and nutrients, and enhancing other soil ecosystem services. We compared wind and water erosion potential, soil compaction, soil hydraulic properties, soil organic C ( SOC), and soil fertility between biomass removal from WSGs and corn residue removal from rainfed no-till continuous corn on a marginally productive site on a silty clay loam in eastern Nebraska after 2 and 3 years of management. The field-scale treatments were as follows: (i) switchgrass ( Panicum virgatum L.), (ii) big bluestem ( Andropogon gerardii Vitman), and (iii) low-diversity grass mixture [big bluestem, indiangrass ( Sorghastrum nutans (L.) Nash), and sideoats grama ( Bouteloua curtipendula (Michx.) Torr.)], and (iv) 50% corn residue removal with three replications. Across years, corn residue removal increased wind-erodible fraction from 41% to 86% and reduced wet aggregate stability from 1.70 to 1.15 mm compared with WSGs in the upper 7.5 cm soil depth. Corn residue removal also reduced water retention by 15% between −33 and −300 kPa potentials and plant-available water by 25% in the upper 7.5 cm soil depth. However, corn residue removal did not affect final water infiltration, SOC concentration, soil fertility, and other properties. Overall, corn residue removal increases erosion potential and reduces water retention shortly after removal, suggesting that biomass removal from perennial WSGs is a desirable alternative to corn residue removal for biofuel production and maintenance of soil ecosystem services. [ABSTRACT FROM AUTHOR]

Corn (Zea mays L.) residue is one of the sources of soil organic carbon (SOC) in row cropping systems in the Midwest. Farmers in Iowa apply liquid N to corn residue after harvest, assuming it will increase corn residue decomposition. The objective of this study was to investigate the effectiveness of N application for increasing corn residue decomposition. The study included two fields with three N rates (0, 34, or 67 kg N ha-1) of liquid 32% urea ammonium nitrate (UAN) applied after harvest, and two laboratory incubation experiments with three temperatures (0, 25, and 35°C) in 2012 and 2013. The experiment design was a randomized complete block in four replications in a no-tillage system (NT). The average mass of residue organic carbon (OC) after harvest was in the range of 1.6 to 1.7 Mg ha-1. Residue OC in the field declined sharply in both years, particularly during the first 3 mo, with no significant difference between N treatments. The only difference in field residue decomposition occurred after 6 mo (P = 0.0241) at the Olson location in 2012, where a greater (>21%) amount of remaining OC was associated with 0 kg N ha-1 than with other N treatments. The incubation study showed an increasing rate of residue decomposition with increasing soil temperature with no N application effects on residue decomposition. These findings show that air and soil temperatures are the driving force for residue decomposition, especially at 25°C, rather than with N addition. [ABSTRACT FROM AUTHOR]

A soil incubation experiment was conducted to investigate the effect of biochar application (2% w/w) on urea hydrolysis and inorganic nitrogen accumulation. Fresh biochars were produced from maize stover that was pyrolyzed at 300 °C, 500 °C, and 700 °C. Then the matured biochars were obtained via a 50 days maturing process. Biochar prepared at 700 °C strongly accelerated the urea hydrolysis and increased soil pH. Fresh biochar, especially when pyrolyzed at low temperature, contained a relatively high concentration of labile carbon and 43% to 64% could be oxidized within 40 days of maturing incubation. The labile carbon in fresh biochars led to microbes thriving and resulted in an accelerated shortterm nitrogen (N) turnover, i.e., at an early stage of incubation, fresh biochar increased mineralization of soil organic N by 79 mg·kg-1 to 449 mg·kg-1. However, a reduction of soil available N contents induced by microbial immobilization effect was observed at the end of incubation. The authors concluded that aged biochar was suitable for simultaneous soil amendment with urea rather than newly produced biochar. This is because aged biochar can avoid high soil available N accumulation; thus it can decrease the risk of inorganic N leaching loss. [ABSTRACT FROM AUTHOR]

In this study, different nanocellulose (NC) products were manufactured from corncob residue (CCR) through sulfuric acid hydrolysis, formic acid hydrolysis, and TEMPO-mediated oxidation methods (the products were referred as SCN, FCN, and TCN, respectively). The properties of NC products and their impact on rheological behavior of paper coatings were comparatively studied. Results showed that compared to SCN and TCN, FCN exhibited large dimensions, limited negative surface charge, and poor stability in their aqueous suspensions, while the FCN aqueous suspension displayed the highest viscoelastic modulus due to the formation of highly entangled network. In paper coatings, SCN exhibited superior thickening and promoted rheological function due to their highly charged surface and strong interactions with pigments and immobilized water molecules, in comparison with other NC products. This study verified that the NC derived from CCR could be utilized as green and renewable additives to improve rheological properties for paper coatings. [ABSTRACT FROM AUTHOR]

Corn (Zea mays L.) residue is a forage source and a biofuel feedstock. Excessive residue harvest may, however, result in increased soil erosion risks and degraded soil properties. Aerial interseeding of a cover crop (CC) before harvesting corn may offset adverse effects of residue harvest. We studied the impacts of harvesting 71% of corn residue with and without aerially interseeded winter rye (Secale cereale L.) CC on wind and water erosion potential, soil organic carbon (SOC), nutrients, soil water content, and corn yields in a farmer's field under irrigated strip till continuous corn on a sandy loam in the western Corn Belt from 2013 to 2016. Interseeded CC biomass yield ranged from 0.2 to 3.4 Mg ha-1. Corn residue harvest reduced geometric mean diameter of dry soil aggregates and increased wind erodible fraction (<0.84 mm aggregates) by 0, 27, and 37% in the first, second, and third year, respectively, indicating that residue harvest increased the soil's susceptibility to wind erosion. Cover crop had no effect on geometric mean diameter and erodible fraction. Residue harvest reduced near-surface water content but CC had no effect. Treatments did not affect fertility properties and corn yield. In spring, surface cover was 24.7% in residue-harvested plots without CC and 65.3% in residueharvested plots with CC, indicating that CC provided soil protective cover. Overall. interseeded grass CC may not rapidly improve soil properties, but the added soil cover provided by the interseeded CC could partly offset the effect of residue harvest on wind erosion potential in sandy loam soils. [ABSTRACT FROM AUTHOR]

Quantitative analysis of enzyme adsorption and hydrolysis were performed for sieve-based grinding corn stover (SGCS) and ultrafine grinding corn stover (UGCS) 1 SGCS: Sieve-based grinding corn stover; UGCS: ultrafine ground corn stover.¹ with different enzyme consumptions. The UGCS presented significantly higher enzyme adsorption quantity (5.15 mg/g for UGCS, 1.33 mg/g for SGCS), higher glucose yield (49.75% for UGCS, 28.75% for SGCS) under 20 FPU/g and higher binding enzyme proportion (41.32% for UGCS, 10.64% for SGCS under 5 FPU/g) which can be attributed to the more accessible microstructure properties. The relationship between enzyme adsorption and hydrolytic production was directly proportional for SGCS (GY1 = 21.04 x AQ1 + 1.86 (R² = 0.95)) while was exponential for UGCS (GY2 = 49.42 x (1 - e-0.57 x AQ2) (R² = 0.99)), 2 GY1 and GY2: glucose yield of SGCS and UGCS; AQ1 and AQ2: adsorption quantities of SGCS and UGCS.² indicating that overmuch enzyme consumption was not advisable for UGCS at economical aspect. [ABSTRACT FROM AUTHOR]

Levulinic acid (LA) is an important platform compound that can be obtained from biomass resources. Using corncobs as the raw material that had already removed the hemicellulose, this work studied the relevant hydrolysis kinetics. The kinetic experiments were performed at various temperatures in the range of 150 °C to 180 °C and sulfuric acid concentrations between 0.2 mol/L and 0.8 mol/L in a reactor designed by the authors. The highest yield of LA was obtained at 150 °C and 0.8 mol/L H2SO4 at 58.0 mol%. A new simple kinetic model that consists of four first-order reactions was proposed; the model assumes that humins can be only converted from 5- hydroxymethylfurfural (5-HMF). A modified parameter fitting method that contained equality constraints and a weighted objective function was applied in this study. The kinetic model was in excellent agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The inhibition of the enzymatic saccharification of acid pretreated corn stover (PCS) biomass due to several compounds either present in PCS or produced during saccharification has been studied. The prospective inhibitors tested were glucose (≤110 g L −1 ), celobiose (≤24 g L −1 ), xylose (≤50 g L −1 ), arabinose (≤1.5 g L −1 ), furfural (≤2 g L −1 ), hydroxymethylfurfural (≤1 g L −1 ), acetic acid (≤4 g L −1 ), and lignin (≤50 g L −1 ). Each of these compounds was added at three different concentrations, being the concentration intervals different according to standard maximum concentrations of such compounds in the reaction medium, previously measured and described in literature. In addition, these experiments were employed to evaluate the standard error present during the evaluation of the results obtained in the inhibition reactions. Those results show that significant inhibition was only detected for lignin (more than 25 g L −1 ) and it was also appreciable for glucose at high concentrations (above 75 g L −1 ), although it was not remarkable at medium concentrations (40 g L −1 ). On the other hand, neither of the remaining compounds tested presented any significant inhibitory effect at the usual process concentration range. [ABSTRACT FROM AUTHOR]

Corn stover was pretreated with submerged lime plus shock, a mechanical treatment that subjects biomass to a detonation wave. In a series of bottles, pretreated corn stover was countercurrently saccharified with enzyme loadings of CTec3 (1 mg protein/g dry biomass), CTec3 (1 mg protein/g dry biomass) + HTec3 (1 mg protein/g dry biomass), and CTec3 (2 mg protein/g dry biomass) + HTec3 (2 mg protein/g dry biomass). To reach a given glucan conversion at low enzyme loadings, countercurrent saccharification reduced enzyme loadings by 1.9 times compared with batch saccharification but was not helpful at high enzyme loadings. To preserve the sugars during saccharification, volatile anti-microbials (chloroform and essential oils from thyme and oregano) prevent the growth of contaminating microorganisms. A simple packed column is proposed to perform commercial-scale countercurrent saccharification. [ABSTRACT FROM AUTHOR]

Corn (Zea mays L.) residue grazing can be an important component of crop- livestock systems, but its long-term impacts on soil properties are not well understood. Some producers are concerned that residue grazing can induce soil compaction and reduce crop yields. We assessed the 16-yr cumulative effect of cattle grazing of corn residues on soil compaction, structural quality, soil C, fertility and microbial communities and studied their correlations with corn and soybean [Glycine max (L.) Merr.] yield in a sprinkler-irrigated no-till corn-soybean system on a Tomek silt loam in eastern Nebraska. Three treatments were studied: (i) fall grazing [4.4-6.2 animal unit-months (AUM) ha-1], (ii) spring grazing (9.3-13.0 AUM ha-1) and (iii) control (no grazing). Cattle grazing did not affect bulk density, wet soil aggregate stability, particulate organic matter, soil organic C, and nutrients except Ca and S. Spring grazing increased the cone index (soil compaction parameter) by 1.3 to 3.4 times relative to the control, but fall grazing had no effect. The increase in soil compaction caused by spring grazing was below the threshold limit (£2 MPa) and did not reduce corn and soybean yields. Although grazing had a positive effect on the biomass of most microbial groups, the results were not significant, except for actinomycetes, which increased with residue grazing (p = 0.06). Overall, long-term corn residue grazing had little or no effect on soil properties and the small changes did not affect crop yields. [ABSTRACT FROM AUTHOR]

The present investigation was aimed towards pretreatment optimization of corncob to maximize cellulose and hemicellulose recovery, followed by substrate selection for holocellulase production using psychrotolerant Aspergillus niger SH3. Dilute alkali pretreatment (1.5% NaOH) resulted in higher recovery of cellulose (59.66%) and hemicellulose (28.34%) from corncob, while corn stover proved to be the best substrate for holocellulase production. Further, saccharification was optimized by Box-Behnken design to select the suitable conditions for maximum sugar release from pretreated corncob. The optimum conditions for maximum sugar release were 8% (w/v) substrate loading, 11 FPU/gds enzyme loading at temperature 38 °C and pH 3.0 which resulted in 114.5% higher sugar yield (912 mg/gds of pretreated biomass) as compared with un-optimized conditions (425.35 mg/gds). Theoretical yield of 48.8% ethanol was achieved through simultaneous saccharification and fermentation (SSF) using pretreated corncob. This study illustrates the potential of different corn residues as a promising substrate for bioethanol production. [ABSTRACT FROM AUTHOR]

The extraction of nanocrystalline cellulose from agro-residues is an interesting alternative to recover these materials. In the present study, nanocrystalline cellulose was extracted from pine wood and corncob. In addition, microcrystalline cellulose was used as a reference to compare results. Initially, the lignocellulosic residues were submitted to delignification pre-treatments. At the end of the process, the bleached fibre was submitted to acid hydrolysis. Additionally, microparticles were obtained from the spray-drying of the nanocrystalline cellulose suspensions. The nanocrystalline cellulose yield for the pine wood was 9.0-% of the value attained for the microcrystalline cellulose. For the corncob, the value was 23.5-%. Therefore, complementary studies are necessary to improve the yield. The spray-dried microparticles showed a crystallinity index of 67.8-% for the pine wood, 70.9-% for the corncob and 79.3-% for the microcrystalline cellulose. These microparticles have great potential for use in the production of polymer composites processed by extrusion. [ABSTRACT FROM AUTHOR]

An awareness of the transformation of plant residues returned to cultivated soils is vital for a better understanding of carbon cycles, the maintenance of soil fertility and the practice of a sustainable agriculture. The transformation of maize ( Zea mays L) straw residues into soil organic matter (SOM) in a one year incubation experiment was studied in a soil that had been under long term cultivation with wheat ( Triticum aestivum L) for > 30 years. A novel sequential exhaustive extraction and fractionation procedure isolated a series of fractions of SOM. The samples were characterized by elemental and δ 13 C analyses, by amino acids and neutral sugars analyses, by Fourier transformed infrared (FTIR) spectrometry, and by solid state 13 C nuclear magnetic resonance (NMR) spectroscopy and with chemical shift anisotropy (CSA) –filter and dipolar dephasing (DD) spectral editing NMR techniques. The δ 13 C data indicated that 59% and 38% of the newly transformed organic carbon was in the humic and fulvic acid fractions, respectively, and in general a greater proportion of the transformed carbon was in the fractions isolated at the higher pH values. Results for SOM fractions from the amended soil indicate dominant contributions from carbohydrate and lignin-like material, and that can be clearly identified by FTIR, CP/TOSS, and spectral editing of CSA-filter and DD. The compositions of the fractions from the amended and non-amended soils fractions can be clearly differentiated using principal component analysis (PCA) for the data collected. The sequential extraction procedure showed that the hydrophilicity of humic fractions increased as the result of the maize amendment, and the aromaticity of the fraction decreased. The data may give some indications of transformations that take place during humification processes. [ABSTRACT FROM AUTHOR]

Abstract 1 1 Returning the whole corn stalk into field was designated as ‘CCR’, which means the whole corn stalk was chopped into small pieces then spread them on soil surface; leaving standing corn residue in the field was designated as ‘SCR’, which means cutting and removing the top stalk but leaving the bottom stalk standing; Daily average soil heat flux was designated as ‘DG’. Complete thawing time is defined as the time in which no ice remained in the soil. Standing corn residue has been proven to reduce wind erosion in Northeast China, but how standing corn residue affects soils during winter remained unclear. Our objective was to compare soil frost depth associated with two zero-tillage methods [i.e., chopping corn stalks into small sections then spread them on soil (hereafter referred to as ‘CCR’) and standing corn residue (hereafter referred to as ‘SCR’)]. Frost tubes were used to determine soil frost depth, and soil heat flux plates were used to measure soil heat flux 8-cm beneath the soil surface. Compared with CCR treatment, SCR reduced maximum soil frost depth significantly ( p < 0.05) due to thicker snow cover, which insulated the soil surface from cold winter air. And the thicker snow cover hastened the frozen soil completely thawed approximate 20 days, which has implications for early sowing. Early sowing meant that corn could have longer growing time, which could help long-growing-time corn varieties become maturity before killing frost in cold areas, longer growing time could also result in fully filled grain, and increase economic profit for farmers. [ABSTRACT FROM AUTHOR]

In recent years, man has become more aware of the fact that today’s approach to energy saving is unsustainable. It is believed that in the near future, biomass will increasingly become of interest as one of the most promising renewable energy sources. The paper describes one example of the use of biomass (corn cob) in the process of production of thermal energy, i.e. in the process of seedcorn drying. The purpose of the investigations reported in the paper was to define the use of corn cob as a fuel to increase energy efficiency. Additionally, energy efficiency was explained through hourly consumption of corn cob in thermogens, which was further compared with consumption of conventional fuels (natural gas). [ABSTRACT FROM PUBLISHER]

Supercritical impregnation (SFI) can carry polar compounds, such as polyphenols, in corn starch aerogels, forming new delivery systems with wide application in the food industry. This study investigated the effect of SFI pressure (22.5, 30.0, and 37.5 MPa) and temperature (45, 55, and 65 °C) on the loading of corn starch aerogels with polyphenols from passion fruit bagasse. SFI was performed in static mode with a fixed depressurization rate of 1.3 MPa/min. The best SFI condition for total phenolics and antioxidant capacity was 65 °C/37.5 MPa. The SFI efficiency was also observed from the decrease in the aerogel surface area (from 63.621 to 51.662 m2/g), volume (from 0.285 to 0.129 cm3/g) and particle diameter (from 8.976 to 4.788 nm). These findings may foster the use of SFI in the development of polyphenol delivery systems for nutraceuticals and food products. [Display omitted] • Polyphenols from passion fruit residue were impregnated in corn starch aerogels. • The effects of pressure and temperature on the impregnation of polyphenols were investigated. • Polar compounds were impregnated at 65 °C and 37.5 MPa by supercritical impregnation. • Impregnation at 65 °C and 37.5 MPa did not reduce the antioxidant capacities. [ABSTRACT FROM AUTHOR]

[Display omitted] • The first example of RCF of fermentation residues was illustrated. • The fermented stover residues are abundant renewable lignin-rich bioresources. • Lignins of fermented residues contain lower molecular weight and β- O -4′ linkages. • 28.5 wt% yield of phenolic monomers was obtained at 220 °C over a Pd/C catalyst. The fermented corn stover residues are abundant renewable lignin-rich bioresources that show great potential to produce aromatic phenols. However, selective catalytic hydrogenolysis of this residual material still remains challenge to obtain high yields. Herein, a novel strategy to produce monophenolic compounds from the fermented stover over a commercial Pd/C catalyst was proposed. Taking the reaction temperature as the key variable, the highest monomer yield was 28.5 wt% at 220 °C in compaction with that of the pristine corn stover (22.8 wt%). The enhanced monophenol yield was due to the higher contents of lignin and less recalcitrance in the fermented stover. Moreover, the van Krevelen diagram revealed a slight selective C O bond scission of lignin macromolecular during fermentation as well as the dehydration and deoxygenation in hydrogenolysis reaction. Overall, this work opens a new avenue for the valorization of lignin through reductive catalytic fractionation of agricultural wastes. [ABSTRACT FROM AUTHOR]

• WSOC played an important role in apoptosis than DCM-extracted fraction in PM 2.5. • The aromatic and double-bond carbon structure in WSOC contributes to apoptosis. • The WSOC from secondary products of motor vehicle exhaust is the risk drivers for apoptosis. • The WSOC from coal and corn residues burning is the risk drivers for apoptosis. Identify risk drivers is the key condition in air pollution control, and biological effect-directed analysis is the most commented method for combing chemical identify and human health. The water-soluble organic matter contained in PM 2.5 plays an important role in human health, while it is also the most difficult to identify its chemical information. Exploring the structural characteristics and pollution sources of its key toxic components is the optimized strategy to meet this question. In this study, the induction of apoptosis by the water-soluble fractions (WSF) of PM 2.5 samples collected in 10 major cities in China over a period of 1 year was observed in vitro in Beas-2b cells. Organic carbon structures were examined using nuclear magnetic resonance; air potential sources were identified using δ13C and 14C isotopic markers. Apoptosis induction by WSF in PM 2.5 was generally stronger in northern cities than in southern cities, and in winter than in summer. Organic compounds with aromatic and double-bond carbon structures from secondary products of motor vehicle exhausts, coal-derived emissions, and emissions derived from the burning of core residues may be primarily responsible for apoptosis induction by PM 2.5. Our results will contribute to understanding the toxic substances contained in WSF and provide basic data for accurate pollution control. [ABSTRACT FROM AUTHOR]

Organic residues contain essential nutrients (carbon, nitrogen, and phosphorus), matter that can be used as a culture medium for the growth of a certain microorganism to produce certain enzymes. In this case the enzyme of interest produced is amylase from a ceparium of fungi and bacteria of the Microbial Diversity and Interaction Laboratory (LDIM-ITESI) using starch as a substrate, which degrades starch to dextrin, maltose, or free glucose, so they have application at an industrial level in the manufacture of detergents, textiles, paper industry and in food production. The strains with the highest production of amylase were isolated from residues such as corn stover, corn straw and agave bagasse. [ABSTRACT FROM AUTHOR]

Corn is the second most plentiful cereal grown for human consumption. Corn has several pests and diseases and various kind of pesticides are used for controlling these, and reducing their damage. In this study, 49 pesticide residues in 34 corn samples and nine corn field soil samples collected from eight cities of Khuzestan province as the main agricultural products in Iran were analyzed using a miniaturized QuEChERS extraction method. In addition, non-carcinogen and carcinogen health risk assessments were evaluated. Indoxacarb, metribuzin, propamocarb, and thiabendazole residues were detected in some corn samples. In addition, atrazine, cymoxanil, and propamocarb residues were found in some corn field soil samples. Results indicated that 35% of corn samples had at least one pesticide, of course, less than the maximum residue limit (MRL), except thiabendazole in 12 samples includes residue more than the acceptable limit. In addition, the Hazard index (HI) of corn samples was 1.83 × 10−4 and 8.53 × 10−4 in adults and children, respectively. No significant carcinogenic risk threatens corn consumers. [Display omitted] • 49 pesticide residues were analyzed in 34 corn and 9 soil samples. • Pesticides residues in corn were < MRL, except for the fungicide, thiabendazole. • Hazard index (HI) of corn was 1.83E-04 and 8.53E-04 in adults and children. • Health risk assessment showed that HQ exhibits no risk to human health. [ABSTRACT FROM AUTHOR]

A thermophilic strain Bacillus coagulans (NBRC 12714) was employed to produce l -lactic acid from corn stover hydrolysate in membrane integrated continuous fermentation. The strain NBRC 12714 metabolized glucose and xylose by the Embden–Meyerhof-Parnas pathway (EMP) and the pentose phosphate pathway (PPP), producing l -lactic acid with optical purity >99.5%. The overall l -lactic acid titer of 92 g/l with a yield of 0.91 g/g and a productivity of 13.8 g/l/h were achieved at a dilution rate of 0.15 h −1 . The productivity obtained was 1.6-fold than that of conventional continuous fermentation without cell recycling, and also was the highest among the relevant studies ever reported. These results indicated that the process developed had great potential for economical industrial production of l -lactic acid from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

In this work, nanocellulose was extracted from bleached corncob residue (CCR), an underutilized lignocellulose waste from furfural industry, using four different methods (i.e. sulfuric acid hydrolysis, formic acid (FA) hydrolysis, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation, and pulp refining, respectively). The self-assembled structure, morphology, dimension, crystallinity, chemical structure and thermal stability of prepared nanocellulose were investigated. FA hydrolysis produced longer cellulose nanocrystals (CNCs) than the one obtained by sulfuric acid hydrolysis, and resulted in high crystallinity and thermal stability due to its preferential degradation of amorphous cellulose and lignin. The cellulose nanofibrils (CNFs) with fine and individualized structure could be isolated by TEMPO-mediated oxidation. In comparison with other nanocellulose products, the intensive pulp refining led to the CNFs with the longest length and the thickest diameter. This comparative study can help to provide an insight into the utilization of CCR as a potential source for nanocellulose production. [ABSTRACT FROM AUTHOR]

In this study, biochar was produced from maize residues (cobs, husks, leaves) in a lab-scale pyrolysis reactor without using a purging gas. The physicochemical properties of biomass and biochar were analysed. Box–Behnken design was used to optimise operational conditions for biochar yields. Multivariate correlations of biochar yields were established using reduced quadratic models with R 2 = 0.9949, 0.9801 and 0.9876 for cobs, husks and leaves, respectively. Biochar yields were negatively correlated with the temperature, which was significantly influenced by the exothermic reactions during the pyrolysis of maize residues. The heating rate was found to have the least effect on biochar yields. Under optimal conditions, the maximum biochar yields from cobs, husks and leaves were 33.42, 30.69 and 37.91%, respectively. The highest biochar yield from maize leaves was obtained at a temperature of 300 °C, a heating rate of 15 °C/min and a holding time of 30 min. [ABSTRACT FROM AUTHOR]

DOT Integrase (IntDOT) is a member of the tyrosine recombinase family. It catalyzes the integration and excision reactions of an integrative and conjugative element (ICE) called CTnDOT. Like other tyrosine recombinases, the integration reaction proceeds by two sets of strand exchanges between the attDOT site on CTnDOT and an attB site in the host chromosome. The strand exchanges occur seven bases apart and define an overlap region. After the first strand exchanges a Holliday Junction (HJ) intermediate is formed. Previous work showed that a valine (V95) in a predicted alpha helix in the N-terminus of IntDOT is required for resolution of HJs to substrates and products. We have identified two additional hydrophobic residues in the helix (A92 and F99) that are involved in resolution of HJs. IntDOT proteins with substitutions at these residues form aberrant complexes in an electrophoretic mobility shift assay. We propose that these three residues participate in hydrophobic interactions that are involved in forming higher-order complexes and resolution of HJs. [ABSTRACT FROM AUTHOR]

This study assessed the feasibility of mobilising maize and wheat residues for large-scale bioenergy applications in South Africa by establishing sustainable residue removal rates and cost of supply based on different production regions. A key objective was to refine the methodology for estimating crop residue harvesting for bioenergy use, while maintaining soil productivity and avoiding displacement of competing residue uses. At current conditions, the sustainable bioenergy potential from maize and wheat residues was estimated to be about 104 PJ. There is potential to increase the amount of crop residues to 238 PJ through measures such as no till cultivation and adopting improved cropping systems. These estimates were based on minimum residues requirements of 2 t ha −1 for soil erosion control and additional residue amounts to maintain 2% SOC level. At the farm gate, crop residues cost between 0.9 and 1.7 $ GJ −1 . About 96% of these residues are available below 1.5 $ GJ −1 . In the improved scenario, up to 85% of the biomass is below 1.3 $ GJ −1 . For biomass deliveries at the conversion plant, about 36% is below 5 $ GJ −1 while in the optimised scenario, about 87% is delivered below 5$ GJ −1 . Co-firing residues with coal results in lower cost of electricity compared to other renewables and significant GHG (CO 2 eq) emissions reduction (up to 0.72 tons MWh −1 ). Establishing sustainable crop residue supply systems in South Africa could start by utilising the existing agricultural infrastructure to secure supply and develop a functional market. It would then be necessary to incentivise improvements across the value chain. [ABSTRACT FROM AUTHOR]

Super-critical water gasification of biomass is a promising technology for hydrogen production. In order to achieve high hydrogen yield and complete gasification, the operating parameters were investigated and the solid residual was analyzed to study the reaction bottleneck by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental results showed that most organic functional groups in corn cob were consumed by super-critical water above 500 °C, however, the aromatic substance and cyclic ketone were remained. The K2CO3 has the best catalytic effect due to the formation of pore structure in the residual particle surface. The carbon gasification efficiency of 97.97% and the hydrogen yield was 50.28 mol/kg. [ABSTRACT FROM AUTHOR]

Understanding long-term microbial immobilization of nitrogen (N) fertilizer is essential for N management in agricultural soils. Evaluating the transformation and accumulation of N fertilizer into microbial residues is critical for developing such an understanding due to the requirement of time-integrated biomarkers and a 15 N-labeling technique. By tracing the dynamics of amino sugars derived from annually applied fertilizer over 8 years, we investigated the influence of continuous maize residue mulching on the temporal immobilization of fertilizer N in an agricultural soil and quantified the turnover of microbial residues in situ . We found that the amino sugar transformation rate from fertilizer N was constant over time in both fertilization-only and maize residue mulching managements, but it was significantly higher in the upper cultivation layer (0–10 cm) after maize residue mulching. Mulching with maize residue facilitated initial fertilizer N transformation, while the subsequent 7-year application maintained the increased transformation rate. Consequently, the accumulation of fertilizer-derived amino sugars increased linearly in both managements within the 8 years of our field experiment. The mean residence time (MRT) of soil amino sugar-N was estimated by using extrapolation and first-order kinetics approaches, respectively. The calculated MRT of amino sugar-N using first-order kinetics (78 and 154 years at 0–10 and 10–20 cm, respectively) was slightly shorter than that estimated by the extrapolation (89 and 165 years at 0–10 and 10–20 cm, respectively) in the fertilization-only management. Mulching with maize residue did not change the MRT of amino sugar-N because maize residue addition enhanced the immobilization of maize residue-derived N or the transformation of indigenous soil N in addition to those of fertilizer N, leading to the same proportion of new N assimilated in microbial residues. [ABSTRACT FROM AUTHOR]

Corn is the most commonly produced crop in the world producing immense agricultural residues, including corn husks. In search for handling corn husks as a fiber source, the quality of fibers extracted from different parts of corn husks by water retting is investigated. The effects of the location of the leaves in the husks and the part of the leaves where the fibers were extracted from on the mechanical, physical, and chemical characteristics of the fibers have been investigated. The coarseness of extracted fibers decreases from outer to the inner leaves in the husk and from the lower to the upper parts of the leaves. Breaking tenacity, breaking force, and elongation at break values of the fibers increase from the upper to the lower parts of the husk leaves. The fibers from the lower parts of the leaves showed greater hemicellulose, pectin, moisture content, and water absorption capacity compared to fibers obtained from the upper part of the corn husk leaves. With superior mechanical properties and lower moisture content and water absorption fibers from the lower parts of corn husk leaves may be considered advantageous for technical use such as in fiberboards. The fibers from the upper portion that are finer and can hold more moisture are more advantageous in terms of comfort aspects. The mechanical properties of the obtained water-retted fibers have been found to be superior to the corn husk fibers of prior studies produced by alkalization. [ABSTRACT FROM AUTHOR]