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In order to compare conservation tillage treatments on physical properties of soil, a randomized complete block design (RCBD) with three replications was conducted in the field of Agricultural Research, Education and Extension Center of Markazi Province of Iran, during the two cropping seasons (2012 and 2013). The treatments were: 1) Moldboard plow + disc (conventional method), 2) Chisel packer, 3) Combined Tillage Tools, and 4) Direct seeding. In both cropping seasons, the tillage operations were carried out based on the experimental treatments in a plot containing corn residues (var. SC-704). The physical properties of soil included soil bulk density, soil permeability (infiltration), mean weight diameter (MWD) of aggregates, and soil mechanical strength. Results showed that the tillage method had no significant effect (p>0.05) on wheat yield at the 5% level. The water infiltration rate for the conventional, chisel packer, combined plow, and direct seeding was 6.8, 8.9, 8.2, and 12.1 mm h-1 respectively. Tillage methods had no significant effects (p>0.05) on soil bulk density in depths from 0 to 10 cm. In depths from 10 to 20 cm, the lowest soil bulk density belonged to the conventional tillage. [ABSTRACT FROM AUTHOR]

Various models and simplified equations are available to predict wind erosion potential. However, their performance can be often site-specific, depending on soil characteristics and agronomic practices, warranting site-specific model validations. Thus, in this study, we 1) validated the wind erodible fraction (WEF) predictive equations by Fryrear et al. (1994) and López et al. (2007) and 2) estimated the total soil loss with the Single-event Wind Erosion Evaluation Program (SWEEP) using 3-yr measured data from six experiments located across a precipitation gradient in the central Great Plains. Each site had three corn (Zea mays L.) residue removal treatments: control (no removal), grazed, and baled. The measured and predicted WEF were significantly correlated. While the Fryrear et al. (1994) equation performed better than the López et al. (2007) equation, it underestimated WEF with 59% uncertainty across site-years. To reduce this underestimation and uncertainty, we developed a new statistical equation (WEF% = 84.3 + 2.64 × % silt-0.30 × % clay-7.43 × % organic matter-0.15 × % residue cover; r2 = 0.56). The predictive ability of the new equation was, however, no better than that of the existing predictive equations, suggesting the need for further refinement of WEF equations for the region. Simulated total soil loss by wind using the SWEEP model indicated that corn residue baling may increase soil loss if residue cover drops below 20% in the study region. Overall, the existing WEF equations could under- or over-estimate WEF based on site-specific residue management, warranting further model refinement and site-specific validation, whereas the SWEEP estimated soil loss corroborates the critical importance of maintaining sufficient residue cover (>20%) to reduce wind erosion. • The predictive ability of existing wind erodible fraction (WEF) equations varies. • The equation by Fryrear et al. (1994) predicted WEF better than other equations. • Addition of residue cover (%) to WEF equation did not improve the WEF prediction. • Wind erosion simulation highlighted the importance of retaining >20% residue cover. [ABSTRACT FROM AUTHOR]

In order to understand if and how composting modifies the dynamics of incorporation of organic carbon and nitrogen to soil aggregates during residue decomposition, we studied samples of a soil amended with fresh or composted plant residues in the laboratory. Samples from the surface horizon of a Luvisol (representative of large agricultural regions in northern Europe) were amended with fresh or composted 13C–15N-labelled wheat, corn and rapeseed residues and incubated in the laboratory during three years. Aggregates of samples taken at the initial time, after 45 days and after three years of incubation were fractionated by size; OC and N concentrations plus isotopic signatures of C and N were analysed in each aggregate fraction. Both fresh and composted residues addition increased aggregate stability at 45 days, but the effect almost disappeared after three years. The addition of the residues increased OC and N contents with respect to the control soils after three years. The additional OC and N coming from residues were initially incorporated preferentially into 0.05–0.2-mm aggregates, as indicated by isotopic signature analyses, and later redistributed homogeneously among all size fractions. After three years of incubation, 11% of plant residue OC remained in soil when these were added fresh, and 22% if they were previously composted, whereas similar N percentages (26–27%) remained for fresh or composted residues. Overall, a higher amount of inputs from plant residues remained in the soil in the long term when they were previously composted, with respect to non-composted residues. • A soil was incubated with fresh or composted 13C-15N-labelled plant residues. • OC and N concentrations and isotopic signatures were analysed in aggregate fractions. • Initially, residue OC and N incorporated preferentially into 0.05–0.2-mm aggregates. • OC and N were later redistributed homogeneously among all aggregate size fractions. • Plant residue OC and N remained longer in soil when they were previously composted. [ABSTRACT FROM AUTHOR]

Cover crops are increasingly used around the world to enhance N cycling and provide a suite of agroecosystem benefits. The N scavenging capacity of cover crops during winter months is well recognized. Our research characterized spring management effects (e.g., early vs. late termination) on cover crop biomass, decomposition and N release rates, inorganic soil N, soil water dynamics, and corn (Zea mays L.) performance. Cereal rye (Secale cereale L.) was established in Beltsville, MD, to evaluate three management scenarios: no cover crop; early termination (~40 d before corn planting); late termination (~7 d before corn planting). Cereal rye biomass was quantified before termination, and decomposition was tracked over a 24-wk period to assess loss. Soil N content to 100 cm, soil volumetric water content, and corn performance were evaluated over the corn growing season. Low spring precipitation in 2016 led to similar amounts of cereal rye biomass for early and late termination; however, late-terminated cereal rye had lower quality biomass (higher C/N) in both years, leading to slower decomposition and N release rates. Over the corn growing season, late-terminated cereal rye consistently had smaller soil N pools, suggesting more efficient N cycling (better synchrony of N release from cover crop residues with corn N demand) than early-terminated cover crops. Corn yields were smallest following late-terminated cereal rye in 2016, but there was no difference in yields among cover crop treatments in 2017. Overall, we conclude that planting cereal rye cover crops and delaying termination until later in the season will help retain and efficiently cycle N while maintaining high corn yields. [ABSTRACT FROM AUTHOR]

In this study, biodegradable composite films were prepared by using thermoplastic cornstarch matrix and corn husk fiber as a reinforcing filler. The composite films were manufactured via a casting technique using different concentrations of husk fiber (0–8%), and fructose as a plasticizer at a fixed amount of 25% for starch weight. The Physical, thermal, morphological, and tensile characteristics of composite films were investigated. The findings indicated that the incorporation of husk fiber, in general, enhanced the performance of the composite films. There was a noticeable reduction in the density and moisture content of the films, and soil burial assessment showed less resistance to biodegradation. The morphological images presented a consistent structure and excellent compatibility between matrix and reinforcement, which reflected on the improved tensile strength and young modulus as well as the crystallinity index. The thermal stability of composite films has also been enhanced, as evidenced by the increased onset decomposition temperature of the reinforced films compared to neat film. Fourier transform infrared analysis revealed increasing in intermolecular hydrogen bonding following fiber loading. The composite materials prepared using corn husk residues as reinforcement responded to community demand for agricultural and polymeric waste disposal and added more value to waste management. [ABSTRACT FROM AUTHOR]

This work studied generation of producer gas using oxygen-enriched air and steam mixture as gasifying medium. Corn residues consisting of cobs and stover were used as biomass feedstock. Both corn residues were pelletized and gasified separately with normal air, oxygen enriched air and steam mixture in a fixed bed reactor. Effects of oxygen concentration in enriched air (21-50%), equivalence ratio (0.15-0.35), and steam to biomass ratio (0-0.8) on the yield of product gas, the combustible gas composition such as H2, CO, and CH4, the lower heating value (LHV), and the gasification efficiency were investigated. It was found that the decrease in nitrogen dilution in oxygen enriched air increased proportion of combustible gas components, improved the LHV of producer gas, but gasification efficiency was not affected. The increase in equivalence ratio favoured high product gas yield but decreased combustible gas components and LHV. It was also observed that introduction of steam enhanced H2 production but excessive steam degraded fuel gas quality and decreased gasification efficiency. The highest gasification efficiency of each oxygen concentration was at equivalence ratio of 0.3 and steam to biomass ratio of 0.58 for cob, and 0.22 and 0.68 for stover, respectively. [ABSTRACT FROM AUTHOR]

Corn stover removal for biofuels production removes potentially recyclable nutrients and carbon challenging the sustainability of the process. Therefore, this study focused on quantifying the distributions of dry matter, nitrogen, phosphorus, potassium, carbon, sugars and lignin in corn stover fractions, and cobs. In 2016 and 2017, corn plants from different hybrids were collected from a corn field in Ohio at two maturity levels. The properties were evaluated for different non-grain corn plant fractions (i.e., stover fractions above and below ear, and cob). Stover fractions below and above ear (not including cobs) and cobs contributed, respectively, to 42–56%, 31–38%, and 13–18% of the total non-grain aboveground dry matter in 2 years. Glucose and lignin concentrations were uniformly distributed and ranged from 321 to 407 mg/g and 87 to 158 mg/g, respectively, for both years. Cobs contained the highest concentration of other sugars (351–361 mg/g) in both years, compared to 217–298 mg/g in other fractions. Nitrogen and phosphorus were uniformly distributed across the different corn stover and cob fractions, ranging between 4–20 mg/g and 0.2–1.5 mg/g, respectively. Potassium concentration was the highest in stover fraction below ear (10–24 mg/g) compared to 5–11 mg/g in other fractions. The results suggest that harvesting cob and above ear stover fractions from the field would allow corn stover collection with suitable sugar concentrations for biofuels/products while retaining stover fractions with higher nutrients concentrations in the field. [ABSTRACT FROM AUTHOR]

• Two bio-binders are obtained by extraction process on corn cob and on flax fine. • Development of wholly bio-based composites with hemp shiv and corn cob residues is investigated. • The mechanical properties are sufficient to ensure self-bearing. • Thermal conductivity of composites is low enough to use them as insulating materials. • Composites show high Moisture Buffer Value. The present study has investigated the scope for valuation of agro-resources by-products as aggregates and as binding material to produce rigid fully bio-based composite panels. Two types of aggregates: hemp shiv and corn cob residues (obtained after alkali treatment on the corn cob), and six types of green binders are investigated. Specimens are produced to verify the gluing effect, to characterize mechanical, thermal and hygric properties of developed composites and to identify the best aggregate-binder mixture. They show interesting thermal conductivity ranging from 67 to 148 mW/(m.K) at dry state, excellent hygric properties (MBV > 2 g/(m2).%RH)) and high enough mechanical properties to be self bearing. These results suggest that developed composites can be used as building materials but not for the same types of use. In fact, some composites would be more suitable for thermal insulating products and others would be better suited for indoor facing panels. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to measure rates of ruminal disappearance, and energy and nutrient availability and N balance among cows fed corn husks, leaves, or stalks. Ruminal disappearance was estimated after incubation of polyester bags containing husks, leaves or stalks in 2 separate ruminally cannulated cows in a completely randomized design. Organic matter (OM) that initially disappeared was greatest for stalks and least for husks and leaves (P < 0.01), but amounts of NDF that initially disappeared was greatest for husks, intermediate for stalks, and least for leaves (P < 0.01). Amounts of DM and OM that slowly disappeared were greatest in husks, intermediate in leaves, and least in stalks (P < 0.01). However, amounts of NDF that slowly disappeared were greatest in leaves, intermediate in husks, and least in stalks (P < 0.01). Rate of DM and OM disappearance was greater for leaves, intermediate for husks and least for stalks, but rate of NDF disappearance was greatest for stalks, intermediate for leaves, and least for husks (P < 0.01). Energy and nutrient availability in husks, leaves, or stalks were measured by feeding ruminally cannulated cows husk-, leaf-, or stalk-based diets in a replicated Latin square. Digestible energy lost as methane was less (P = 0.02) when cows were fed leaves in comparison to husks or stalks, and metabolizable energy (Mcal/kg DM) was greater (P = 0.03) when cows were fed husks and leaves compared with stalks. Heat production (Mcal/d) was not different (P = 0.74) between husks, leaves, or stalks; however, amounts of heat produced as a proportion of digestible energy intake were less (P = 0.05) among cows fed leaves in comparison to stalks or husks. Subsequently, there was a tendency (P = 0.06) for net energy available for maintenance from leaves (1.42 Mcal/kg DM) to be greater than stalks (0.91 Mcal/kg DM), and husks (1.30 Mcal/kg DM) were intermediate. Nitrogen balance was greater when cows were fed leaves, intermediate for husks, and least for stalks (P = 0.01). Total tract digestion of NDF was greater (P < 0.01) for husks and leaves compared with stalks. Husks had greater (P = 0.04) OM digestibility in comparison to stalks, and leaves were intermediate. Apparently, greater production of methane from husks in comparison to leaves limited amounts of energy available for maintenance from husks even though total-tract nutrient digestion was greatest when cows were fed husks or leaves. [ABSTRACT FROM AUTHOR]

Highlights • Bioextrusion improved enzymatic hydrolysis efficiency of raw corn crop residues. • FTCM assisted to study the surface cellulose accessibility profile. • Negative impact of high S/L ratio was not due to the lack of exposed cellulose. • Alkaline pretreatment strongly limits bioextrusion's positive influence. Abstract Lignocellulosic biomass is a sustainable source of renewable substrate to produce low carbon footprint energy and materials. Biomass conversion is usually performed in two steps: a biomass pretreatment for improving cellulose accessibility followed by enzymatic hydrolysis of cellulose. In this study we investigated the efficiency of a bioextrusion pretreatment (extrusion in the presence of cellulase enzyme) for production of reducing sugars from corn crop agricultural residues. Our results demonstrate that bioextrusion increased the reducing sugar conversion yield by at least 94% at high solid/liquid ratio (14%–40%). Monitoring biomass surface with carbohydrate-binding modules (FTCM-depletion assay) revealed that well known negative impact of high solid/liquid ratio on conversion yield is not due to the lack of exposed cellulose which was abundant under such conditions. Bioextrusion was found to be less efficient on alkaline pretreated biomass but being a mild and solvent limiting pretreatment, it might help to minimize the waste stream. [ABSTRACT FROM AUTHOR]

Abstract Integrated crop-livestock (ICL) systems are being promoted as environmentally favorable alternatives to traditional crop agriculture and livestock production. There are few, if any, evaluation studies of the hydrologic response of watersheds to the implementation of ICL systems. Thus, we applied the Soil and Water Assessment Tool (SWAT) model to simulate the potential impacts of ICL systems on water yield and its hydrological components using a large agricultural dominated watershed. In this study, the integration of grazing operations with cropping systems represented cattle grazing under three typical crop rotations: (i) continuous corn (Zea mays L.; 1-year rotation), (ii) conventional (corn-soybean [ Glycine max (L.) Merr.]; 2-year rotation), and (iii) winter cover crops (corn-soybean-oats (Avena sativa L.)/winter barley (Hordeum vulgare L.); 3-year rotation). Modeling results showed a significant reduction in water yield over a long-term period simulation (31 years) when grazing of corn residue or winter barley was scheduled within the rotations. When compared to scenarios without grazing operations, the reduction in water yield was 14.7% under corn-soybean rotation (corn as the forage grazed), 12.5% under continuous corn rotation, 6.4% under corn-soybean-oats/winter barley rotation (corn as the forage grazed), and 3% under corn-soybean-oats/winter barley rotation (winter barley as the forage grazed). Of the three components that constitute water yield (i.e. , surface runoff, lateral and groundwater flow), only surface runoff was reduced when integrating grazing into the cropping system. Instead, lateral and groundwater flows increased when ICL systems were scheduled in the watershed. Groundwater flow was the hydrological component with the highest relative impact on streamflow. These results indicate that ICL systems can positively affect processes involved in soil water storage and transit. Runoff reduction benefits of ICL systems might be helpful in improving the environmental quality of receiving waterbodies and in reducing flood-risk potential. These systems over the long-term could benefit the watershed's hydrological cycle through increased baseflow. Overall, this study suggests new watershed-scale benefits of ICL systems with important hydrological implications that might be of interest for agricultural watershed planners. Highlights • SWAT simulations showed reduction in water yield when ICL systems were included within the crop rotations. • Surface runoff was reduced when integrating grazing into the cropping systems. • Lateral and groundwater flows increased when ICL systems were implemented within the Big Sioux River watershed. • ICL systems can positively affect processes involved in soil water storage and transit. • Runoff reduction benefits from ICL systems can improve water quality and reduce flood-risk potential. [ABSTRACT FROM AUTHOR]

Cellulose nanofiber is an environmentally friendly reinforcing phase extractable from plants, with potential application in composites. Due to the cell wall structure differences, plant parenchyma cells might be easier to nanofibrillate than sclerenchyma cells of wood pulp fibers, resulting in lower extraction costs. This study assessed the extraction of nanofibers from residues like corn husk, banana peel, cabbage leaf, and taro leaf using a kitchen blender. Fibrillation was evaluated based on the strength of paper-like sheets produced from the nanofibers. Corn husk was nanofibrillated by the shortest blending time among the sources considered, and delivered the highest sheet strength. The blending time needed was significantly shorter than that needed to fibrillate hardwood pulp fibers. [ABSTRACT FROM AUTHOR]

Soil thermal properties govern the transport and storage of heat in the soil. How management practices such as crop residue removal and cover crop (CC) use affect these soil properties is not well understood. For example, CCs could provide physical cover and improve soil properties after main crop residue removal and thus ameliorate the negative effects of residue removal on soil thermal properties. We measured changes in soil thermal properties including soil thermal conductivity, thermal diffusivity, volumetric heat capacity, and related properties under corn (Zea mays L.) residue removal with and without winter cereal rye (Secale cereale L.) under a 6-yr irrigated no-till continuous corn experiment on a silt loam in south central Nebraska. Cover crops did not affect thermal properties, but corn residue removal reduced field thermal conductivity by 12 to 41% and volumetric heat capacity by 6 to 49% during the growing season for the 0- to 5-cm depth. Residue removal also reduced laboratory thermal conductivity by 19% at -0.03-MPa and by 28% at -1.5-MPa matric potential. Residue removal also reduced volumetric heat capacity in the laboratory by 23% at both matric potentials in the 0- to 10-cm depth. Neither residue removal nor CC affected thermal diffusivity. Thermal conductivity was more strongly correlated with soil water content than with bulk density and soil organic C. Overall, CC had no effect on thermal properties, but corn residue removal could reduce the soil's ability to conduct heat relative to no removal. [ABSTRACT FROM AUTHOR]

Highlights • Maize residue application affected NH 3 and N 2 O emissions. • N 2 O emissions during the non-growing season increased with the quantity of the maize residues applied. • Full maize residue return in combination with N fertilizers can reduce NH 3 and N 2 O losses and increase soil total N and C storage. Abstract Residue return in combination with synthetic nitrogen (N) fertilizer is increasingly being considered to be beneficial to soil fertility and crop yield. In most studies, however, attention has mainly been paid to the way that significant changes in the soil N mineralization process affect the soil N cycle, while the effect of different residue return amounts on ammonia (NH 3) volatilization and nitrous oxide (N 2 O) emissions, potentially the most important components of N losses and environmental effects has, to a certain extent, been neglected, notably in north-eastern China. Therefore, a trial was set up in an Alfisol/arable soil during 2015–2016 to monitor annual NH 3 volatilization and N 2 O emission dynamics from a fertilized maize field with residue return at different rates. Treatments included N fertilizer alone and N fertilizer in combination with either half or the full yield of the maize residue (5.8 × 103 or 11.6 × 103 kg ha−1, respectively) returned to the soil surface after harvest. Over a growing season of maize, the NH 3 volatilization loss rate from the full residue return treatment was 4.6%, which was significantly lower than that in the N fertilizer application only and half residue return plots (6.1%). Meanwhile, residue return rates showed a significant effect on annual N 2 O emissions from the maize system. Half residue return increased N 2 O emission (921.1 g N·ha−1), while full residue return marginally decreased N 2 O emissions (862.6 g N·ha−1) during the maize growing season, compared to the fertilizer-only treatment (881.2 g N·ha−1) (P < 0.05). In spite of the fact that N 2 O emissions in the non-growing season increased with the quantity of maize residue applied, the return of the full yield of maize residue to the soil could reduce both annual NH 3 and annual N 2 O losses and increase soil total N and C storage after long-term use. It is suggested that residue application rate is a key factor when assessing residue benefits but the influence is in a nonlinear pattern. The combined application of full maize residue and synthetic N fertilizer is a promising N management strategy for mitigating gaseous N emissions. [ABSTRACT FROM AUTHOR]

A field experiment was carried out in loam soil at the research station of the College of Agriculture University of Baghdad, using randomized complete block design. The experiment included three local biofertilizers types (Bacillus megaterium, Pseudomonas fluorescens, Azotobacter chrococcum) and an imported biofertilizer (Nitrosoil) by Iraqi’s Ministry of Agriculture, beside, two levels of mineral fertilization (50% and 75%) of the mineral fertilizer recommendation with use of two types of carriers (corn cobs residue, broth liquid medium) in addition to the control treatments. Three replicates for each treatment were used on growth and yield of potato. The results showed a significant effect of biofertilizer in most of the studied traits. The results also showed that use of local biofertilizer with (75%) of mineral fertilizer increased plant height, dry weight of the total vegetables part of plants and total yield tuber with value reached 73.53 cm, 2.48 and 21.97 Mg ha-1 12.33 respectively, compared with the imported biofertilizer and control treatments, while the results showed that the use of half of the fertilizer recommendation with local bio-fertilization carried with liquid medium was sufficient to reach the best amount of nitrogen and phosphorus concentration by the plants in which the value reached to 2.62%, 0.79% compared to imported biofertilizer treatment which showed superiority in the amount of potassium absorbed to the same level of the recommendation and the value was 1.20%. [ABSTRACT FROM AUTHOR]

Corn (Zea Mays L.) residue can be used by cattle producers as a source of forage that can either be grazed or baled. While many studies have evaluated the impact of baling corn residue on subsequent crops, relatively few have evaluated the effect of grazing of corn residue. An on-farm multi-year study (3 or 4 yr) was conducted at six sites in the central United States to determine effects of grazing or baling of corn residue on subsequent grain yield. Most sites were under no-till management and were irrigated. Some locations were in continuous corn while others were in a corn-corn-soybean [Glycine max (L.) Merr.] or corn-soybean rotation. At each location, there were three corn residue treatments: no bale-no graze (CON), baled (BLD), and grazed (GZD) with two or three replicates per treatment. Baling and grazing management was dictated by the cooperating producer. In the spring, corn residue remaining in the CON (10.17 Mg ha-1) was greater (P < 0.01; SEM ± 0.449) than both GZD (8.68 Mg ha-1) and BLD (3.60 Mg ha-1) with GZD being greater (P < 0.01) than BLD. Residue management did not affect (P = 0.26) subsequent grain yield (corn, soybean, or dry bean [Phaseolus vulgaris L.]). Corn yield ranged from 6.2 to 18.2 Mg ha-1 with a mean of 14.0 Mg ha-1. Results indicate that, in the short term, baling or grazing of corn residue in high grain yielding fields will not negatively impact grain yield but grazing results in less removal of residue than baling. [ABSTRACT FROM AUTHOR]

Crop residues like corn (Zea mays L) stover are potential feedstock for production of advanced biofuels (e.g., cellulosic ethanol). Utilization of residue like stover for biofuel feedstock may provide economic and greenhouse gas mitigation benefits; however, harvesting these materials must be done in a manner that protects the soil. This paper summarizes an introductory overview presented at the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and Soil Science Society of America (SSSA) workshop in Sacramento, CA, on crop residue removal for advanced biofuel production. Corn stover has been identified as an advanced biofuel feedstock, which could provide agronomic, economic and greenhouse gas mitigation benefits. However, stover harvest may result in soil exposed to erosive forces, and inadequate residue input for sustaining soil organic matter, resulting in soil degradation and other negative environmental consequences. Thus, strategies to protect the soil resource to balance current and future societal needs are required. Returning adequate residue and/or adding cover crops can mitigate or reduce risks to soil properties, which may be adversely impacted by harvesting crop residue. It is paramount to safeguard the soil so this indispensable resource continues providing a wide range of services including feeding and clothing a growing population. [ABSTRACT FROM AUTHOR]

To determine the effect of harvest method and ammoniation on both in vivo and in vitro digestibility of corn residue, six corn residue treatments consisting of three different harvest methods either with or without anhydrous ammonia chemical treatment (5.5% of dry matter [DM]) were evaluated. The harvest methods included conventional rake-and-bale (CONV) and New Holland Cornrower with eight rows (8ROW) or two rows (2ROW) of corn stalks chopped into the windrow containing the tailings (leaf, husk, and upper stem) from eight rows of harvested corn (ammoniated bales of each harvest method resulted in treatments COVAM, 8RAM, and 2RAM). Nine crossbred wether lambs (49.2 ± 0.5 kg BW) were fed 64.2% corn residue, 29.8% wet corn gluten feed, 3.3% smooth-bromegrass hay, and 2.8% mineral mix (DM basis) in a 9 × 6 Latin rectangle metabolism study with a 3 × 2 factorial treatment to measure total tract disappearance. Six 21-d periods consisted of 14-d adaptation and 7-d total fecal collection, and lambs were fed ad libitum (110% of the previous day's DM intake [DMI]) during days 1 to 12 and reduced to 95% of ad libitum intake for days 13 to 21. There was a harvest method by ammoniation interaction (P < 0.01) for ad libitum DMI (days 7 to 11). Ammoniation increased (P < 0.01) intake across all harvest methods, where 2RAM DMI was 4.1%, COVAM was 3.6%, and 8RAM was 3.1%, which were all different (P < 0.01) from each other, but all untreated residues were consumed at 2.6% of BW (P ≥ 0.92) regardless of harvest method. There were no interactions (P > 0.34) between harvest method and ammoniation for any total tract or in vitro digestibility estimate. Harvest method affected (P < 0.04) DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility, where 2ROW was greater than both CONV and 8ROW, which did not differ. The organic matter (OM) digestibility (P = 0.12) and digestible energy (DE; P = 0.30) followed the same numerical trend. Both in vitro DM digestibility (IVDMD) and in vitro OM digestibility (IVOMD) of the residue were affected (P < 0.01) by harvest method, with 2ROW being greater (P < 0.01) than both CONV and 8ROW. For IVDMD, 8ROW was not (P = 0.77) different from CONV, but 8ROW IVOMD was lower (P = 0.03) than CONV. Ammoniation improved (P < 0.01) DM, OM, NDF, and ADF digestibility of all harvest methods, resulting in a 26% increase (P < 0.01) in DE due to ammoniation. Similar digestibility improvements were observed in vitro with ammoniation improving IVDMD and IVOMD by 23% and 20%, respectively. Both selective harvest methods and ammoniation can improve the feeding value of baled corn residue. [ABSTRACT FROM AUTHOR]

Abstract In this research a hybrid thermochemical and biochemical approach is proposed to produce biocarbon, biomethane and biofertilizer from corn residue using the concept of resource recovery from biowaste. In this approach, corn residue is first pretreated in hydrothermal carbonization process to produce solid biocarbon. Hydrothermal process water, a co-product of hydrothermal carbonization process underwent fast anaerobic digestion to produce biomethane and biofertilizer. Effects of operating conditions (process temperature and residence time) on both biocarbon and hydrothermal process water contents were studied. Four selected hydrothermal temperatures of 200 °C, 220 °C, 240 °C and 260 °C and their three corresponding residence times of 10 min, 20 min and 30 min were considered. Among these 12 hydrothermal processes, 240 °C for 30 min process produced hybrid bioenergy of 14.26 MJkg−1 of raw corn residue with an overall energy yield of 78.65%. Biocarbon produced at 240 °C for 30 min and 260 °C for 10–30 min were comparable to pulverized coal used in power plants, which contained high heating values of 23.01 MJkg−1 to 24.70 MJkg−1. All anaerobic digestion digestate are nutrient enriched and useable as liquid fertilizer. Graphical abstract Image Highlights • Hydrothermally treated corn residue can produce hybrid bioenergy. • Biocarbon produced from corn residue has the potential to substitute coal. • Hydrothermal process water has the potential to produce biogas. • Nutrient-enriched AD digestate is available to use as biofertilizer. [ABSTRACT FROM AUTHOR]

Abstract Herbaceous biomass can be used as an alternative for wood to produce fuel pellets, but obtaining the appropriate properties for these pellets is a challenge. Worldwide, corn harvest residues have significant potential as a herbaceous biomass. The objective was to investigate influences on the mechanical properties of corn stover and corn cob pellets. The parameters varied included particle size and the moisture content of raw material, the shares of wood and additives, and pressing intensity. Corn cob pellets had better properties with bulk densities of 547.7–719.5 kg/m3, a mechanical durability of 88.0–98.8%, and pellet yields of 98.2–100.0%. When corn stover was used, these properties were 510.1–644.3 kg/m3, 77.9–99.2%, and 41.1–100.0%. Pressing intensity and blending with wood had a very strong significance (p < 0.001) in terms of improving the properties of corn stover pellets. These pellets reached quality thresholds when the extrusion ratio was raised to 5, when blended with 40% of wood, or when an admixture with 1% of pressing aid was used. To keep the pellets' moisture content under a limit of 15%, corn stover should be conditioned to a moisture content no higher than 17%. When corn cobs were used, particle size and pressing intensity showed a very strong significance (p < 0.001). Thresholds for corn cob pellets were achieved by either raising the extrusion ratio to 4 or reducing the particle size using sieve mesh size larger than the pellet press die openings. Highlights • As a raw material, corn cobs can be more easily pelletized than corn stover. • An increased pressing intensity produced quality pellets from corn harvest residues. • Corn stover conditioned to a moisture content below 17% produced quality pellets. • Blending with wood was significant for improving the corn stover pellets properties. • A larger corn cobs particle size was significant for improving pellet properties. [ABSTRACT FROM AUTHOR]

Corn residue grazing can provide a valuable and cost effective means of feeding cattle and is a common practice in most corn producing states. Mechanical means of residue removal (baling) is also often practiced as a means of harvesting cattle feed. However, there are concerns about the effects of management practices that remove crop residue on soil processes such as compaction, aggregation, and N cycling. To study these concerns, an experiment with four treatments including control, light grazing, heavy grazing, and baling was carried out for 5 years at the University of Nebraska-Lincoln Water Resources Field Laboratory near Brule, NE. Soil penetration resistance was measured after 3, 4, and 5 years of residue removal. Wind erodible fraction, mean weight diameter of dry aggregates, and soil total N were measured after 5 years. Corn yields were determined throughout the study. Results indicate that light grazing showed little or no difference from the no residue removal treatment, but heavy grazing and baled treatments often had higher penetration resistance, indicating that high rates of residue removal may increase risks of soil compaction. However, compaction did not appear to be cumulative over time. No significant differences were observed in wind erodible fraction and dry aggregate mean weight diameter. However, there were trends that suggest heavy grazing and baling may, in the long term, reduce dry aggregate stability, increasing wind erosion potential. Results also show that in the surface 0-2.5 cm grazing animals may increase soil total N and that baling residue may decrease soil N content. There was no impact on corn yields throughout the study. Overall, corn residue grazing and baling appear to have little or no adverse effects on soil compaction, aggregation, or nitrogen cycling after 5 years. [ABSTRACT FROM AUTHOR]

Significant research was done concerning the suitability of lignocellulosic wastes as heavy metal adsorbents. However, most of them do not focus on regeneration, environmental stability, or disposal of spent adsorbents, critical for commercial application. The scientific value of the current research is the production of fired clay bricks as a safe method for the removal of Ni(II), Zn(II), and Cd(II) adsorbents based on sunflower and corn residues, with retention efficiencies of more than 93.4%, 98.7%, and 98.5% for these contaminants, respectively. The bricks were molded by uniaxial compression and fired at 950 °C, and their performance as building bricks was evaluated, showing differences depending on biomass but no effect associated with heavy metals at the concentrations used. In the fired bricks, the biomasses served to form pores, increasing porosity to +46%, beneficial due to the low weight and hypothetical insulating capacity of the products. However, the bricks' quality and mechanical performance decreased compared to the control samples. Mechanical tests showed that bricks with corn were better than bricks with sunflower (compressive strength 7.96 MPa). The results presented here can be considered a starting point for the safe removal of spent lignocellulosic adsorbents using them as pore formers in building bricks. [Display omitted] • Sunflower and corn residues were used as adsorbents for Ni(II), Zn(II), Cd(II). • Spent adsorbents were stabilized in fired clay bricks. • Bricks with 20 V % were subjected to physical and mechanical tests. • Biomass increased porosity but decreased brick quality and mechanical performance. • The bricks with corn were the best according to the technical criteria analyzed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A strategy was developed to distinguish and quantitate four kinds of BMZs residues in corn. • The Fe 3 O 4 @SiO 2 @Ag-SH substrate was prepared for SERS measurements. • PCA, PLS-DA and FCM models were established to classify and identify CBZ, BN, THM and TBZ. • PLSR and SVR were employed for quantitative analysis of BMZs residues. In this study, surface-enhanced Raman spectroscopy (SERS) combined with chemometric methods were developed for qualitative and quantitative analysis of four benzimidazole (BMZs) residues in corn. Sulfhydryl functionalized Fe 3 O 4 @SiO 2 @Ag-SH magnetic SERS substrates were prepared to obtain the SERS spectra of four BMZs for chemometric analysis. The partial least squares regression discrimination analysis (PLS-DA) model performed best, with a recall rate upwards 99.17%, and could successfully distinguish four BMZs. Under the support vector machine regression (SVR) model, the detection limits of carbendazim, benomyl, thiophanate-methyl and thiabendazole were 0.055 mg/L, 0.056 mg/L, 0.067 mg/L and 0.093 mg/L, respectively; the average recovery was in the range of 85.6%–107.5%. Furthermore, the method verified by HPLC, and the results showed that there was no significant difference between two methods (p > 0.05). Therefore, the strategy based on SERS coupling chemometrics can be served as a promising tool for rapid determination of BMZs residues in food. [ABSTRACT FROM AUTHOR]

Low or variable cover crop (CC) biomass production could limit CC benefits. Longer CC growing periods via late termination could increase CC benefits, especially under limited crop residue return. We studied whether early (2–3 wk before planting)- or late (at planting)-terminated winter rye (Secale cereale L.) CC maintains soil properties, crop yields, and farm income under 0%, 25%, 50%, 75%, and 100% corn (Zea mays L.) residue removal in rainfed and irrigated no-till in the U.S. Great Plains after 6 yr. Early-terminated CCs produced < 1 Mg ha-1 of biomass while late-terminated CCs averaged 1.6 Mg ha-1 at the rainfed site and 3.0 Mg ha-1 at the irrigated site. At the rainfed site, CC termination date did not affect soils, but ≥ 75% residue removal reduced soil organic matter (OM) fraction concentrations and 100% reduced mean weight diameter of water-stable aggregates (MWD) in the 0–5 cm depth. At the irrigated site, late-terminated CC increased MWD by 0.22 mm and OM concentration by 5.1 g kg-1 compared with no CC. At the same site, 100% residue removal reduced microbial biomass, while ≥ 50% removal reduced OM concentration by 7.6 g kg-1, available water, and MWD by 0.75 mm relative to no removal. Cover crops only partially offset the adverse effects of residue removal if biomass production was 3 Mg ha-1 yr-1. Corn yield was generally unaffected. High residue removal rates offset CC-induced reduction in net income. Overall, late-terminated CC partially maintains soil health indicators following residue removal and minimally impacts crop yields and economics. • High corn residue removal rates (≥50%) negatively affected most soil health indicators. • Cover crop (CC) improved some soil health indicators only when it produced 3 Mg ha-1 yr-1 of biomass. • Cover crop and corn residue removal did not affect crop yields in most years. • Income from high rates of residue removal can offset CC adoption costs. • Cover crop could not completely offset crop residue removal effects on soil properties. [ABSTRACT FROM AUTHOR]

Violet phosphorene (VP) have been proved to be more stable than black phosphorene, but few reports for its application in electrochemical sensors. In this study, a highly-stable VP decorated with phosphorus-doped hierarchically porous carbon microsphere (PCM) with multiple enzyme-like activities as a nanozyme sensing platform for portable intelligent analysis of mycophenolic acid (MPA) in silage with machine learning (ML) assistance is successfully fabricated. The pore size distribution on the PCM surface is discussed using N 2 adsorption tests, and morphological characterization indicates that the PCM is embedded in the layers of lamellar VP. The affinity of the VP-PCM nanozyme obtained under the guidance of the ML model reaches K m = 12.4 μmol/L for MPA. The VP-PCM/SPCE for the efficient detection of MPA exhibits high sensitivity, a wide detection range of 2.49 μmol/L - 71.14 μmol/L with a low limit of detection of 18.7 nmol/L. The proposed ML model with high prediction accuracy (R2 = 0.9999, MAPEP = 0.0081) assists the nanozyme sensor for intelligent and rapid quantification of MPA residues in corn silage and wheat silage with satisfactory recoveries of 93.33%–102.33%. The excellent biomimetic sensing properties of the VP-PCM nanozyme are driving the development of a novel MPA analysis strategy assisted by ML in the context of production requirements of livestock safety. [ABSTRACT FROM AUTHOR]

Agriculture waste residue (corn stalk), a rich source of reducing sugars explored in the present study for the production of bioethanol using hydrolytic enzymes and fermenting yeast cocktails. Corn stalk pulp was biologically pretreated using hydrolytic enzymes cocktail of ligninase, cellulase and xylanase produced from Bacillus sp. PHS-05, Bacillus subtilis CP-S66 and Bacillus safensis XP-S7 with 2.34 ± 0.28 U/ml, 6.89 ± 0.36 U/ml and 11.9 ± 0.22 U/ml enzyme activities respectively. This biological pretreatment of corn stalk pulp resulted into 51.41 ± 0.34 % removal of lignin and 77.43 ± 2.44 % extraction of reducing sugar (C5 & C6). The changes occur in corn stalk pulp after enzymatic saccharification was confirmed by Fourier-Transform Infrared Spectroscopy (FTIR). Corn stalk sugar hydrolysate was co-fermented into 0.77 ± 0.06 g/g bioethanol with yield of 26.6 ± 0.46 g/kg of biomass, using Kluyveromyces marxianus MTCC 1498 and Saccharomyces cerevisiae. Further , purity (94.27 %) and volumetric productivity (0.20 ± 0.04 g/L/h) of bioethanol was confirmed using Gas Chromatography-Mass Spectrometry (GC-MS). Present findings provide valuable insight to obtain second generation biofuels to solve energy crisis, and environmental problems besides boosting socioeconomic prosperity through sustainable management of agro-residues. [Display omitted] • Lignocellulosic corn stalk residue held great potential for bioethanol production. • Enzymatic pretreatment resulted in 51.41 ± 0.34 % lignin removal from corn stalk pulp. • Saccharification of corn stalk pulp hydrolysate released 77.43 ± 2.44 % C5&C6 sugars. • Co-fermentation of C5 & C6 sugars resulted into 26.6 ± 0.46 g bioethanol/Kg of biomass. • Volumetric productivity of bioethanol was 0.20 ± 0.04 g/L/h with 94.27 % purity. [ABSTRACT FROM AUTHOR]

• Lignocellulosic bioplastic shows strong mechanical and water resistance properties. • Lignocellulosic bioplastic is degradable and recyclable, enabling a good closed-loop cycle. • The production of lignocellulosic bioplastic is based on the existing xylose industry. • The production of lignocellulosic bioplastic has a low environmental impact. Lignocellulosic biomass is a favorable resource for the production of plastics, which are traditionally based on fossil fuels. However, the production of bioplastics from woody biomass usually requires the fractionation of the main components, namely cellulose, hemicellulose, and lignin, which increases the economic cost and environmental impact, and most bioplastics have poor water stability and mechanical properties, which seriously hinder the practical application. Herein, a simple method for the production of bioplastics was developed that avoids the fractionation of lignin from cellulose and produces bioplastics with good properties. Specifically, corn cob residues after xylose extraction, as a by-product of the existing xylose industry, were dissolved in a metal salt solution (ZnCl 2 /CaCl 2 system) to produce high-performance bioplastics. The resulting lignocellulosic bioplastic is biodegradable, recyclable, water stable (No decomposition within two months), and most importantly, offers exceptional mechanical properties (136 MPa) and lower environmental impact compared to conventional plastics. Overall, this environmentally friendly lignocellulosic bioplastic demonstrated in our study could be a promising substitute for petrochemical plastics. [ABSTRACT FROM AUTHOR]

• A DTL method based on 1D-CNN and FT-NIR spectra to detect pesticide residues in corn oil is proposed. • The method enhances the accuracy of predicting chlorpyrifos residual levels in corn oil. • DTL addresses performance gaps between datasets and improves model generalization. • The developed DTL method provides an efficient and precise approach to detecting food safety issues. This study introduces a novel deep transfer learning (DTL) approach based on convolutional neural networks (CNN) and Fourier transform near-infrared (FT-NIR) spectroscopy to enhance the accuracy of predicting the residual levels of chlorpyrifos in corn oil. The method proposed involves creating a 1D-CNN model using existing data and utilizing DTL to enhance the performance of a new model by transferring the parameters learned from the trained model. The research findings demonstrate that compared to the CNN model, the proposed TL method achieves superior predictive accuracy while utilizing a smaller amount of FT-NIR spectral data, thus reducing the reliance on labeled FT-NIR spectral data for model training. Specifically, the coefficient of determination (R P 2) reaches 0.9754, and the relative percent deviation (RPD) is 6.4575. This study confirms that the developed DTL method based on CNN and FT-NIR provides an efficient and precise approach to detecting food safety issues. In addition, this method is not only applicable for pesticide residue detection in edible oils based on near-infrared spectroscopy but can also be used for the chemometric analysis of FT-NIR spectral data in other fields. [ABSTRACT FROM AUTHOR]

The study was conducted to determine the effect of fermented extruded corn stover on nutrient digestibility and milk composition in colostrum of pregnant sows. A total of 48 pregnant sows (24 Landrace and 24 Yorkshire) were randomly assigned into four experimental treatment groups (0, 10%, 15%, 20% fermented extruded corn stover). The results of nutrient digestibility (Table 2) showed that in crude protein and neutral detergent fibre, there were no significant differences between the control group and 10% fermented extruded stover (P > 0.05). However, these results in energy and acid detergent fibre showed a significant differences between control group and all the experimental groups (P > 0.05), respectively. In fat, lactose and non-fat solids, there were no significant differences between control group and experimental groups (P > 0.05), respectively. There was a significant difference in protein between control group and experimental group (P < 0.05). Our findings suggest that with the increase of fiber content in feed, protein and lactose content are increased in colostrum of pregnant sows and there is little effect on digestibility. [ABSTRACT FROM AUTHOR]

Water contamination of As is a big issue in many areas around the globe. Therefore, cheap and efficient techniques are essential facing traditional treatment methods. Then, biochars (BC) emerged recently as material that can be used for As removal. However, research about efficiency of BC produced from local feedstock is still needed. The purpose of this study is to assess the efficiency of BC produced from sugarcane bagasse (SB) together with corncob husk (CH) with and without Fe(III) (BC Fe ) modification to be used for removal of As(III) from waters. The BC and BC Fe produced at different pyrolysis temperatures were characterised using FTIR and SEM/EDS. Adsorption capacities of BC and BC Fe were evaluated via batch adsorption, desorption and column tests and their performance was compared with adsorption using activated carbon. The results showed that Fe modification improve substantially the As(III) adsorption in a way that both BC Fe-SB and BC Fe-CH removed from 85% to 99.9% from 1000 µg/L As(III) solutions. Both materials fitted well in Langmuir model and the maximum adsorption capacity was 20 mg/g for BC Fe-SB and 50 mg/g for BC Fe-CH . The adsorption kinetics of BC Fe was fast (≤ 30 min) and it had a better performance than activated carbon. The column tests showed that the process is efficient even at high As(III) concentrations. The fast removal process and good removal results make the BC Fe-SB and BC Fe-CH attractive for in situ and commercial (filters) use, since time and efficiency are required in new technologies. [ABSTRACT FROM AUTHOR]

Soil management techniques, such as mulching, are used to enhance soil organic carbon sequestration. However, we demonstrate that the potential of crop residue mulching to increase soil organic carbon (SOC) sequestration varies by cropping system and soil type in Austrian agricultural soils. Effects of mulch (as harvested crop residues applied at 1.0 t C ha −1 ) on soil and microbial carbon (C) and nitrogen (N) and soil δ 13 C were measured in an Austrian Cambisol field experiment with sole maize or vetch or vetch-maize rotation cropping systems after five years with or without mulching to elucidate how SOC is affected. The direct role of mulch on SOC in different soil types was also investigated in a similar greenhouse mesocosm study with controlled moisture using the same Cambisols and an Austrian agricultural Chernozem. Only sole maize cropping in the field experiment resulted in higher SOC with mulching and when legumes were included in a legume-maize rotation SOC did not improve. Mulching in the field experiment only resulted in higher SOC in the top 0–5 cm of soils with sole maize cropping (by 22%) compared to soils without mulch. Although mulch did not increase SOC in vetch-maize rotation, the δ 13 C of SOC was less negative with mulch indicating larger C contribution from maize than vetch mulch. After four years of annual soybean-maize rotation in the mesocosm experiment, no significant differences in SOC were observed in Cambisols with or without mulch. Again, δ 13 C of both soil types was less negative with mulching indicating a larger C contribution from maize than soybean mulch. No relationships between microbial biomass C and N and SOC were observed in either experiment and only soil N concentration was positively correlated with SOC. Together these studies indicate that maize can increase SOC when crop residues are applied in Austrian Cambisols but that inclusion of legume production and legume mulch in rotation can mute these benefits. [ABSTRACT FROM AUTHOR]

Enhanced understanding of biomass removal effects on soil quality could be achieved with greater knowledge of how corn residue removal and cover crops interact to affect surface pore structure. This study was conducted to evaluate the effects of corn (Zea mays L.) residue removal on soil macropore characteristics and to assess the effectiveness of cover crops in mitigating the potential negative impacts of corn biomass removal on surface pore structure. Three different corn residue removal rates and the presence or absence of cover crops were evaluated in a no-till corn/soybean (Glycine max L.) rotation near Brookings, SD. Following eight years of residue removal high (HRR) and medium (MRR) rates of residue removal reduced water inflow into the soil surface compared to the low (LRR) residue removal treatment. The representative mean pore radius (λΔψ) for both rotation phases of LRR approached the same value (≈ 235 µm). However, nine months after corn residue removal the λΔψ for HRR in the soybean phase of the rotation was significantly lower than LRR at 161 µm. There was no significant difference in λΔψ between HRR (214 µm) and LRR (236 µm) 21 months after residue removal during the corn phase of the rotation. The initial reduction in λΔψ following corn residue removal in HRR followed by soil surface recovery the following year suggests that inclusion of decaying corn residue is critical in the maintenance of hydraulically functional macropores in this fine textured soil. Cover crops were not observed to mitigate these impacts of crop residue removal on surface soil structure within the time period of the study. [ABSTRACT FROM AUTHOR]

A process has been disclosed in the present investigation for the production of a formulation of mycopesticide with enhanced shelf life of Trichoderma viride. A comparative evaluation of talc-based and corn cob formulations in the form of seed coat and soil treatment brought to light that the soil treatment significantly enhanced the plant growth performance of pea, green gram and pigeon pea. Among the two formulations, the corn cob formulation proved to be better as the rhizosphere competence of corn cob formulation was superior to that of talc formulation. Our results suggest that corn cob residue is a better substrate owing to high cellulase and spore production. Solid-state fermentation in batch cultures. The biocontrol ability of both formulations was tested against Fusarium in Cajanus species and it was found that the disease incidence was reduced by 86% when the corn cob formulation was given as soil application. [ABSTRACT FROM AUTHOR]

Temporal dynamics of earthworm populations in temperate agroecosystems are related to climatic and edaphic conditions, agricultural management and crop residue inputs. The amount of crop residue present and its suitability as a food resource for earthworms changes as the material decomposes. A readily-decomposable crop residue (low C:N ratio, low lignin content) may be a transient food resource for earthworms, whereas residues that decompose more slowly could be a persistent food resource to sustain the earthworm populations. Chemical composition of the crop residue and the particulate organic matter (POM) content in soil, a measure of the partially-decomposed residues, are indicators of the food resources for earthworms. The objective of this study was to determine how the quantity and chemistry of crop residues, and the soil POM content, were related to earthworm population dynamics during a two-year field experiment in no-till corn-soybean rotations. The high residue treatment provided an additional 3–5 Mg ha −1  y −1 in corn residue, compared to the low residue treatment. As hypothesized, earthworm abundance and biomass were strongly affected by the quantity of crop residues left in the agroecosystem after harvest. Greater corn residue inputs in the high residue treatment supported an earthworm community that had similar species composition and age structure, but was nearly twice as large as the earthworm community in the low residue treatment. Soybean residue appeared to be a transient food resource for earthworm populations in the field. Earthworm abundance and biomass were related to the amount of surface residue present, but were not correlated to the chemical composition of crop residue and the soil POM content during this two-year study. Under field conditions, earthworm populations respond to the quantity of residues present as a food resource rather than the chemical composition of the residue. [ABSTRACT FROM AUTHOR]

Removing plant residue from soil has been shown to have an adverse effect on soil health; however, the addition of cover crops may help mitigate these impacts. This study was conducted to assess the effect of incorporating cover crops on soil health with varying removal rates of corn (Zea mays L.) residues. Corn was grown in rotation with soybean (Glycine max) in a randomized, split-block design with three different corn residue removal levels (37, 55, and 98% of total above-ground C) as whole plot treatments and the presence or absence of cover crops as the split plot treatment. Soil samples were collected from both crop phases following 7 years of cover crop treatment and subjected to a suite of soil health measurements. In the soybean phase immediately following corn residue removal, there were significant (P = 0.025) increases in the erodible fraction (EF) of soil aggregates and reductions in the stable, larger aggregate fractions. Cover crops mitigated these changes in aggregate distributions in the highest residue removal treatment. Residue removal resulted in a significant decrease in fPOM (P = 0.03) while the addition of cover crops increased fPOM levels during the soybean phase (P = 0.002). Residue removal significantly (P = 0.017) decreased soil microbial enzyme activities while cover crops restored activities in the highest residue removal treatment (P = 0.037). We also found higher fungal:bacterial ratios with cover cropping compared to no cover crops. We conclude that cover cropping continued over multiple years can partially mitigate negative effects of crop residue removal on soil health thus limiting soil erosion and maintaining nutrient cycling activities in the vulnerable period following residue removal. [ABSTRACT FROM AUTHOR]

Six ruminally cannulated cows (570 ± 73 kg) fed corn residues were placed in a 6 × 6 Latin square to evaluate predictions of diet composition from ruminally collected diet samples. After complete ruminal evacuation, cows were fed 1-kg meals (dry matter [DM]-basis) containing different combinations of cornstalk and leaf and husk (LH) residues in ratios of 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. Diet samples from each meal were collected by removal of ruminal contents after 1-h and were either unrinsed, hand-rinsed or machine-rinsed to evaluate effects of endogenous compounds on predictions of diet composition. Diet samples were analyzed for neutral (NDF) and acid (ADF) detergent fiber, acid detergent insoluble ash (ADIA), acid detergent lignin (ADL), crude protein (CP), and near infrared reflectance spectroscopy (NIRS) to calculate diet composition. Rinsing type increased NDF and ADF content and decreased ADIA and CP content of diet samples (P < 0.01). Rinsing tended to increase (P < 0.06) ADL content of diet samples. Differences in concentration between cornstalk and LH residues within each chemical component were standardized by calculating a coefficient of variation (CV). Accuracy and precision of estimates of diet composition were analyzed by regressing predicted diet composition and known diet composition. Predictions of diet composition were improved by increasing differences in concentration of chemical components between cornstalk and LH residues up to a CV of 22.6 ± 5.4%. Predictions of diet composition from unrinsed ADIA and machine-rinsed NIRS had the greatest accuracy (slope = 0.98 and 0.95, respectively) and large coefficients of determination (r2 = 0.86 and 0.74, respectively). Subsequently, a field study (Exp. 2) was performed to evaluate predictions of diet composition in cattle (646 ± 89 kg) grazing corn residue. Five cows were placed in 1 of 10 paddocks and allowed to graze continuously or to strip-graze corn residues. Predictions of diet composition from ADIA, ADL, and NIRS did not differ (P = 0.99), and estimates of cornstalk intake tended to be greater (P = 0.09) in strip-grazed compared to continuously grazed cows. These data indicate that diet composition can be predicted by chemical components or NIRS by ruminal collection of diet samples among cattle grazing corn residues. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop prediction equations (EQS) that estimate DE and ME content of corn distillers dried grains with solubles (DDGS) using digestible (DIG) nutrients from in vitro or in vivo assays. Chemical composition data from 12 sources of corn DDGS were obtained using laboratory chemical analysis (LCA) and near infrared spectroscopy (NIRS). In vitro DM disappearance (IVDMD) from gastric and small intestine hydrolysis (IVDMDh), large intestine fermentation (IVDMDf), and total tract digestion (IVDMDt) were also determined along with in vivo apparent total tract digestibility (ATTD) of DM, CP, ether extract (EE), NDF, and ADF, and energy values (GE, DE, and ME). Correlation analysis was used to compare chemical composition from LCA with NIRS, and a stepwise selection of variables was performed using linear regression to establish DE and ME prediction EQS. Composition determined by NIRS did not correlate with values from LCA. Consequently, significance and R2 were poorer when using NIRS data as inputs to predict DE (P = 0.11; R2 = 0.23) and ME (P = 0.11; R² = 0.24). However, when using LCA data, DE (P = 0.04; R² = 0.35) and ME (P = 0.04; R² = 0.52) estimates of corn DDGS obtained from prediction EQS had significant P values, but low R². Better prediction of DE (P < 0.01; R² = 0.83) and ME (P < 0.01; R² = 0.76) was observed when using in vivo DIG nutrients as inputs (DM basis) for DE, kcal/kg = 854.5 + (3.6 × DIG DM, g/kg) + (3.7 × DIG EE, g/kg) + (2.0 × DIG NDF, g/kg) and ME, kcal/kg = 704.5 + (3.3 × DIG DM, g/kg) + (4.8 × DIG EE, g/kg) + (2.6 × DIG NDF, g/kg). In vitro DIG DM, but not in vitro DIG NDF, was selected for use in EQS (7) DE, kcal/kg = 6,383.6 - (42.5 × in vitro DIG DM, g/kg) + (35.4 × DIG EE, g/kg) and (8) ME, kcal/kg = 6,635.1 - (49.8 × in vitro DIG DM, g/kg) + (41.3 × DIG EE, g/kg), but the significance and accuracy for both DE (P = 0.07; R² = 0.45) and ME (P = 0.05; R² = 0.49) predictions was less using in vitro DIG nutrient values than using in vivo DIG nutrient values. If chemical composition was used to replace in vivo EE, along with in vitro DIG NDF and DM, the prediction EQS only used the concentration of ADF and EE as predictors instead of in vitro DIG NDF and DM. In conclusion, in vivo DIG NDF, DM, and EE are the best predictors for DE and ME content of corn DDGS for swine. Using NIRS to determine chemical composition, in vitro DIG NDF, and in vitro DIG DM did not result in accurate predictions of DE and ME. [ABSTRACT FROM AUTHOR]

Purple corn cob (PCC) is an economic anthocyanin-rich source that could serve as food colorant. Pigment extraction from PCC using mild solvent can be difficult because PCC have hard texture and complex matrix. Due to toxicity concerns, most acidified aqueous organic solvents that produce high anthocyanin recovery from PCC are not desirable for food applications. In this study a consumer-friendly solvent (aqueous ethanol) was used at different ethanol ratios (0–100%) to determine PCC anthocyanin recovery as compared to methanol and 70% (v/v) aqueous acetone. Different acidity levels (0–2% 6 N HCl, v/v) were also investigated to see if the PCC pigment extraction yield could be improved by adjusting solvent acidity. The PCC extract obtained by water-ethanol ratio around 1:1 (40%–60% ethanol) achieved highest yield of monomeric anthocyanins (>13.5 mg/g FW) with low polymeric color, comparable to 70% acetone (14.3 mg/g FW). The amount of PCC monomeric anthocyanin and phenolics recovery extracted with different water-ethanol combination could be predicted using quadratic models (R 2  = 0.94 and 0.95). The solvent acidity seemed to impacted water PCC extraction but not much in 70% acetone extraction. This study provides valuable reference information to extract pigments from PCC for potential food application, as synthetic red dye alternatives. [ABSTRACT FROM AUTHOR]

Emission factors for speciated volatile organic compounds (VOCs) from maize residue burning were determined in this study based on chamber experiments. Thirty-six VOC species were identified by Gas Chromatography/Mass Spectrometer (GC/MS). They were classified into six groups, including alkanes, alkenes, oxygenated VOCs, halogenated VOCs, aromatics and other. The emission factor for total VOCs was estimated as about 148 mg kg −1 dry mass burned. About 68.4% of the compounds were aromatics. Field samplings of maize residues were conducted to acquire the information of fuel characteristics including fuel loading, fraction of maize residues that were actually burned as well as proximate and elemental analysis of maize residues. The emission factors were then applied to estimate speciated VOC emissions from maize residue open burning at the provincial level in the upper-northern region of Thailand for the year 2014. Total burned area of maize covered an area of about 500,000 ha which was about 4.7% of the total area of upper-northern region of the country. It was found that total VOC emissions released during the burning season (January–April) was about 79.4 tons. Ethylbenzene, m,p-xylene, 1,2,4-trimethylbenzene, acetaldehyde and o-xylene were the major contributors, accounting for more than 65% of total speciated VOC emissions. [ABSTRACT FROM AUTHOR]

Chemical treatment may improve the nutritional value of corn crop residues, commonly referred to as corn stover, and the potential use of this feed resource for ruminants, including lactating dairy cows. The objective of this study was to determine the effect of prestorage chopping, hydration, and treatment of corn stover with Ca(OH)2 on the feeding value for milk production, milk composition, and dry matter intake (DMI). Multiparous mid-lactation Holstein cows (n = 30) were stratified by parity and milk production and randomly assigned to 1 of 3 diets. Corn stover was chopped, hydrated, and treated with 6% Ca(OH)2 (as-fed basis) and stored in horizontal silo bags. Cows received a control (CON) total mixed ration (TMR) or a TMR in which a mixture of treated corn stover and distillers grains replaced either alfalfa haylage (AHsub) or alfalfa haylage and an additional portion of corn silage (AH+CSsub). Treated corn stover was fed in a TMR at 0, 15, and 30% of the diet DM for the CON, AHsub, and AH+CSsub diets, respectively. Cows were individually fed in tiestalls for 10 wk. Milk production was not altered by treatment. Compared with the CON diet, DMI was reduced when the AHsub diet was fed and tended to be reduced when cows were fed the AH+CSsub diet (25.9, 22.7, and 23.1 ± 0.88 kg/d for CON, AHsub, and AH+CSsub diets, respectively). Energy-corrected milk production per unit of DMI (kg/kg) tended to increase with treated corn stover feeding. Milk composition, energy-corrected milk production, and energy-corrected milk per unit of DMI (kg/kg) were not different among treatments for the 10-wk feeding period. Cows fed the AHsub and AH+CSsub diets had consistent DMI over the 10-wk treatment period, whereas DMI for cows fed the CON diet increased slightly over time. Milk production was not affected by the duration of feeding. These data indicate that corn stover processing, prestorage hydration, and treatment with calcium hydroxide can serve as an alternative to traditional haycrop and corn silage in diets fed to mid-lactation dairy cows. [ABSTRACT FROM AUTHOR]

Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications. [ABSTRACT FROM AUTHOR]

Baling and grazing of corn (Zea mays L.) residues are common practices in irrigated systems to meet the increasing demand for forage. Our understanding of how such practices affect soil properties under different tillage and irrigation levels is, however, still limited. This study assessed the impacts of corn residue baling and grazing on soil organic C (SOC) stocks, particulate organic matter (POM) concentration, soil microbial communities, sorptivity, and wind and water erosion potential under continuous corn managed with two irrigation (full and limited) and two tillage (no-till and strip till) levels after 3 yr on a silt loam in the central Great Plains. On average, residue removal was 66% for baling and 24% for grazing. Baling reduced SOC stocks by 2.16 Mg ha–1 yr–1 for the 0- to 20-cm depth compared with no residue removal, but residue grazing, irrigation, and tillage had no effects. Full irrigation decreased mean weight diameter (MWD) of wet aggregates by 19% compared with limited irrigation, attributed to Na accumulation. No-till had lower wind-erodible fraction and greater microbial biomass than strip till. Regardless of irrigation and tillage, baling increased wind-erodible fraction by 43% and decreased MWD by 56%, POM concentration by 41%, sorptivity by 57%, and microbial biomass in the upper 5-cm depth compared with grazing and no residue removal. Grazing increased POM concentration and actinomycete biomass compared with no residue removal. Overall, changes in soil properties due to baling were larger and more rapid than in most previous studies, while grazing had fewer effects on soil properties. [ABSTRACT FROM AUTHOR]

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The aim of this work is to improve the economic value of corn husk, and to make better use of corn husk nanocellulose (NC). Corn husk NC was extracted via acid hydrolysis, TEMPO oxidation and high intensity ultrasonication methods, which was named AH-NC, TO-NC and US-NC, respectively. The NC was carefully characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and particle size and zeta potential analyzer. The results showed the preparation methods didn’t change the main chemical structure of cellulose. The crystallographic form of the three kinds of NC still was cellulose I. However, the effects of preparation methods on the morphology and properties were obvious. Among the three kinds of NC, TO-NC had the largest aspect ratio, and the best dispersion stability in diameter, but very low thermal stability. The AH-NC exhibited the highest crystallinity and best thermal stability, but a small aspect ratio. US-NC possessed low crystallinity and poor dispersion stability. [ABSTRACT FROM AUTHOR]