Corn Residue Research Articles

Corn grain yield, residue production, and nutrient concentration and extraction is affected by different residue incorporation rates in two biannual crop rotations

Abstract Conservation practices in agriculture using crop rotations and residue management benefit the productivity; these can vary depending on climate and soil conditions, crops, and amount of incorporated residue. The present study evaluated the effect of two biannual rotations; canola (Brassica napus L.) – corn (Zea mays L.) and bean (Phaseolus vulgaris L.) – corn rotations with four residue incorporation rates (0%, 50%, 100%, and 200%) of the preceding crop on corn grain yield, residue production, and nutrient concentration and extraction after two rotation cycles in a volcanic soil of moderate depth in south-central Chile. Grain yield varied between 17.04 and 17.40 Mg/ha, residue production between 16.41 and 16.50 Mg/ha. The preceding crop affected concentration and extraction of some nutrients in both grain and residue. The residue rate affected both concentration and extraction of some nutrients only in the grain. The Ca distribution to the corn grain was negatively affected by both the preceding bean crop and increasing residue incorporation rate. The ranking of total macronutrient extraction in the corn crop was K > N > Ca > P > Mg > S. The extraction means ranged from 320 to 326, 56.0 to 57.1, 365 to 374, 86.5 to 99.3, 39.4 to 42.4, and 22.6 to 23.7 kg/ha, whereas grain nutrient distribution coefficients ranged from 64.5 to 66.8, 90.1 to 90.9, 23.1 to 23.7, 1.3 to 2.0, 50.8 to 57.5, and 60.3 to 60.6 for N, P, K, Ca, Mg and S, respectively.

Optimization Design and Experimental Analysis of Resistance-Reducing Anti-Fracture Rotary Blade Based on DEM Techniques

To address the significant cutting resistance and fracture susceptibility of rotary blades, an innovative blade design was conceived to minimize resistance and enhance fracture resistance. By analyzing the interaction between the blade, soil, and root systems, an optimized design for the blade structure’s breakage resistance was developed. The theory of eccentric circular side cutting edges was applied to redesign the curve of the side cutting edge, and kinematic analysis was conducted to determine the optimal edge angle (26.57°). A flexible body model of corn residues was established, and cutting resistance measurements indicated a 15.1% reduction in cutting resistance. The breakage resistance of the rotary blade was validated using a discrete element method–finite element method (DEM–FEM) coupling approach. The results demonstrated the following: neck stress (−16.85%), specific strength efficiency (+9.72%), specific stiffness efficiency (+9.78%), fatigue life (+39.08%), and ultimate fracture stress (+20.16%), thereby meeting the design objectives. The comparison between field trial results and simulation data showed an error rate (<5%), confirming the simulation test’s feasibility. These findings provide theoretical references for reducing cutting resistance and enhancing breakage resistance in rotary blades.

A Review of the Technological Aspects and Process Optimization of Bioethanol Production From Corn Stover Biomass: Pretreatment Process, Hydrolysis, Fermentation, Purification Process, and Future Perspective

ABSTRACTBioethanol, a sustainable energy solution derived from renewable biomass, has gained prominence, with corn stover emerging as a substantial biomass resource in Indonesia. Corn stover, a corn residue, is one of the top three agricultural wastes worldwide and is abundantly available. However, a significant portion of corn stover is burned in fields rather than utilized for bioethanol production, whereas it has potential as a bioethanol feedstock. As the world strives to realize sustainable and environmentally friendly energy security, bioethanol production from corn stover can be one of the solutions to be developed. Nonetheless, the current immaturity of bioethanol production technology is one of the causes of large‐scale production failure. The present paper comprehensively reviews the technological aspects and process optimization of bioethanol production using corn stover as a feedstock comprising pretreatment, hydrolysis, fermentation, and bioethanol purification processes. According to our critical review, ammonia fiber expansion (AFEX) pretreatment is the most effective conventional pretreatment, with glucose yield up to 90%. Moreover, ultrasound appears to be the most viable option for nonconventional pretreatment of corn stover for producing bioethanol. However, combining ultrasound pretreatment and dilute aqueous ammonia produced 80.6% sugar output. Furthermore, enzymatic hydrolysis emerges as the most effective saccharification, yielding up to 81.39%. Moreover, the fermentation process of corn stover with the saccharification and co‐fermentation (SScF) method and the process optimization with response surface methodology (RSM) could produce bioethanol with a concentration of up to 59.8 g/L and 92.07% ethanol yield, respectively. This review also reveals that pervaporation for the purification process is the best choice for producing bioethanol with high purity up to > 99%. In addition, this method could reduce the energy used by 6.6% lower, 24.2% lower carbon footprint, and have the lowest total capital and production costs compared to conventional molecular sieves and extractive distillation. We believe this review article can provide a reference for selecting the best bioethanol production process from corn stover for further research.

397 Effect of corn harvest with a chopping head on performance of cattle grazing corn residue

Abstract The addition of stalk chopping equipment on combine heads has become more common. An advantage of grazing residue compared with baling, is the ability of cattle to select the more digestible plant parts (husk and leaf). Chopping may impact this ability and decrease the feeding value. Thus, this study was designed to evaluate the effects of chopping residue at harvest on grazing cattle performance. A cornfield (16 Mg grain/ha) was divided into 12 paddocks blocked by location within field and assigned randomly to be harvested using a chopping or non-chopping combine head, with 4 paddocks assigned to be grazed (1.05 ha) from each harvest method (HM) and 4 ungrazed. Growing steers [n = 40; body weight (BW) = 230 ± 3.5 kg] were stratified by BW and assigned randomly to a grazed paddock, with 6 steers in the west block and 4 steers in the east block, with 1 rumen canulated steer (484 ± 33 kg BW) being assigned to each of the east paddocks and used as diet samplers. This resulted in the same grazing pressure (2.9 animal units/ha) in grazed paddocks. Cattle were supplemented at 0.6 % of initial BW with a distillers dried grains plus solubles and mineral mix daily. Cattle grazed for 56 d resulting in 5.4 Animal Units Months/ha. Residue mass of three 0.58 m2 frames was sampled in each paddock before (d -1), during (d 36) and after grazing. Husks were collected from three 5.81 m2 areas per paddock at each of the three timepoints. For residue mass, there was a significant (P < 0.01) HM by time interaction. There was no difference (P = 0.34) in residue mass between HM prior to grazing. However, at 36 d into grazing, residue mass of standard was greater (P = 0.03) than chopped, and post-grazing residue mass of chopped was greater (P = 0.01) than standard. When husk (kg/ha) was evaluated, there was a significant (P < 0.01) HM by time by grazing interaction. Prior to grazing, there was no difference (P ≥ 0.66) in husk between the grazed and ungrazed paddocks within HM. However, husk was less (P < 0.01) for chopped than standard. On d 36, within HM, grazed had less (P < 0.01) husk than the ungrazed. However, within grazing status on d 36 there was no effect (P ≥ 0.52) of HM. Post-grazing there were no differences (P ≥ 0.19) in husk among treatments. Within grazed treatments there was greater (P < 0.01) husk prior to grazing initiation compared with both D36 and post-grazing which did not differ (P ≤ 0.85). Within ungrazed treatments, pre-grazing and D36 did not differ (P ≥ 0.10) in husk, however, husk was lesser (P > 0.01) at the post-grazing sampling. For ADG there was no difference (P = 0.20) between HM, with 0.37 and 0.31kg/d for standard and chopped, respectively. Overall, HM had no effect on grazing cattle performance.

Nutrient Dynamics in Integrated Crop–Livestock Systems: Effects of Stocking Rates and Nitrogen System Fertilization on Litter Decomposition and Release

Current fertilizer recommendations often neglect nutrient cycling across crop rotations. This study aimed to assess the decay rate and nutrient (N, P, K) release patterns of sorghum, black oat, and corn residues (omitido) in an integrated crop–livestock system. The experiment used factorial treatments based on two sward heights (high and low) and two nitrogen fertilization levels (N-pasture at 200 kg N ha−1 and N-corn at 0 kg N ha−1). Litter bags were collected at various intervals from each crop to measure nutrient release patterns and decomposition rates. The results showed that pasture height and nitrogen fertilization significantly influenced decomposition and nutrient release, affecting the subsequent grain crop phase. Potassium was released rapidly and in high amounts. Nitrogen fertilization during the pasture phase prevented nitrogen and phosphorus immobilization in black oat residue and reduced immobilization in corn residue. These findings highlight the importance of accounting for nutrient cycling and decomposition rates in fertilization strategies to enhance the sustainability of integrated crop–livestock systems.

223 Exploring the relationship between corn grain yield and residue quantity and quality

223 Exploring the relationship between corn grain yield and residue quantity and quality

Impact of crop residue removal on crop production, feedstock quality, and theoretical ethanol production in the Mid‐Atlantic United States

AbstractCellulosic biomass‐to‐bioenergy systems provide fuel, reduce emissions, and offer economic benefits. Corn (Zea mays L.) and wheat (Triticum aestivum L.) residues could be used as feedstocks for biofuel production. However, the impact of residue removal on crop productivity in the Mid‐Atlantic region has not been thoroughly assessed. A trial was conducted to assess crop yield and quality response to different biomass retention rates in grain cropping systems during 2015–2017. Various combinations of corn stover (0–10 Mg ha−1) and wheat straw (0–3 Mg ha−1) were applied in a corn–wheat/soybean [Glycine max (L.) Merr.] rotation in New Kent, VA. In Blacksburg, VA, corn stover (0–20 Mg ha−1) was applied in the continuous corn system. Residues were applied after grain harvest over two production cycles for each system. Residue retention showed no significant impact on grain or crop residue yields or nutrient uptake in either system. Treatment minimally impacted feedstock quality, except wheat straw's sulfur (S) concentration, optimized at around 70% retention in New Kent. Theoretical ethanol potential (TEP) and yield remained unaffected by total residue rates in New Kent. In Blacksburg, over 2 years, a minimum TEP for corn stover corresponded to a retention rate of approximately 30%. A retention rate of more than 30% increased TEP, likely due to improved feedstock quality. Nutrient replacement costs for primary macronutrients and S uptake ranged from $18.3 to $36.9 ha−1 for corn stover and $6.1 to $11.8 ha−1 for wheat straw. Residue harvest or addition did not harm short‐term biomass yield in Virginia's grain‐based cropping systems.

Assessing supplementing strategies for beef cattle in a bale grazing system using grass hay during variable winter conditions

IntroductionBeef cattle in the Northern Great Plains of the United States of America are normally kept in open dry lot pens in winter. Practices such as bale grazing, swath grazing, stockpiling, and corn residue grazing, can be used to extend the grazing season and minimize dry lot use. Extending the grazing season has several advantages over dry lot use but arguably the most important benefit is cost savings due to lower labor and input costs. Strategies selected to supplement cattle in extended grazing systems should maintain cost savings while providing required nutrients to cattle. This study was conducted to evaluate supplementing strategies for beef cattle in a bale grazing system using grass hay during variable winter conditions. The study was conducted across variable winter conditions that are encountered in winters in the US Northern Great Plains.MethodsThe study extended over four years. Each year, non-lactating pregnant beef cows (n = 64, year 1; n = 80, year 2, 3, 4) were divided into eight groups of similar average body weight and randomly assigned to one of four bale grazing treatments as follows: a) bale grazing grass hay, b) bale grazing grass hay treated with a liquid supplement, c) bale grazing grass hay and alfalfa hay, and d) bale grazing grass hay and plus 1.8 kg corn DDGS/head/day. Animal performance was assessed from two-day body weights and body condition scores taken at the start and end of the study. Data analysis considered the fixed effects of treatment, year, and treatment x year interaction.ResultsFinal BW tended (P = 0.09) to be greatest following corn DDGS supplementation and lowest when grass hay was offered. The treatment strategy x year interaction (P = 0.026) for ADG showed that corn DDGS supplementation resulted in positive ADG across the years regardless of environmental conditions. Liquid or alfalfa hay supplementation resulted in positive ADG when environmental conditions were favorable. Final BCS (P = 0.005) and BCS change (P = 0.004) were greater following corn DDGS supplementation, intermediate following alfalfa hay or liquid supplementation and lowest when grass hay was fed. Supplementation costs ranged from $1.33 to $1.90/head/day, the highest cost occurred with corn DDGS supplementation mainly due to cost of corn DDGS and labor required to deliver corn DDGS to cattle on pasture.DiscussionAlfalfa hay or molasses-based liquids increased diet CP content but did not supply adequate energy in severely cold winters. Despite relatively higher supplement costs, high energy supplements such as corn DDGS may be required in severely cold winters where cattle require extra energy. Supplement selection should consider supplement effectiveness to meet animal nutrient requirements particularly in adverse winter conditions such as those encountered in the US Northern Great Plains.

RSU-Net: A new method for fine classification of corn residue coverage in black soil area using Chinese GF-1B PMS image

Corn residue coverage (CRC) plays an important role in soil protection, with respect to both the restoration of soil fertility and the reduction of soil erosion, particularly in black soil are-as. Fine classification of areas with high and low coverage of crop residue is essential for accu-rately quantifying the soil protection level; it is insufficient to focus solely on whether the crop residue is covered. Remote sensing images from Chinese GaoFen-1 (GF-1) B, which can be acquired with a high spatial resolution of 2 m and a revisit period of 4d, have potential for the fine classification of high and low coverage of corn residues (HLCCR). To improve the efficiency and accuracy of the fine classification of HLCCR, a deep neural network RSU-Net was proposed in this study. RSU-Net combines residual units with spatial pyramid pooling technology to enhance the ability to extract the features of different coverage types from GF-1 B images. Comparison ex-periments were conducted to validate the effectiveness of RSU-Net and compare it with the classical U-Net. The results show that the overall accuracy, kappa, and mean intersection over union of RSU-Net in fine classification of HLCCR were 86.29%, 0.75, and 0.6844, respectively, and those of U-Net were 84.61%, 0.72, and 0.6474, respectively. Compared with the classical U-Net, the classification accuracy of RSU-Net was improved. These results suggest that RSU-Net has great po-tential for fine classification of HLCCR.

Effects of supplemental rumen-degradable protein, rumen undegradable protein, and energy on performance of growing beef steers grazing corn residue

Effects of supplemental rumen-degradable protein, rumen undegradable protein, and energy on performance of growing beef steers grazing corn residue

Passage and degradation kinetics of solid particles from agricultural residues

The use of waste generated in the agroindustry can result in increased production at a relatively low cost compared to traditional ingredients, especially for producers with easy access to this waste. This study proposes to estimate the kinetics of passage and degradation of corn, soybean, wheat residues and corn silage in the gastrointestinal tract of cattle. Four rumen-fistulated animals with an average weight of 450 ± 50 kg were assigned to four treatments (corn, soybean, wheat residues and corn silage) in a 4×4 Latin square experimental design. The fiber from the residues and corn silage used to estimate the passage kinetics was marked with potassium dichromate, whereas the in situ technique was employed to estimate the fiber degradation kinetics. A larger potentially degradable fraction and a smaller undegradable fraction were observed for corn residue and corn silage, whereas no differences were detected between the materials for passage kinetics. The residue from corn processing is similar to corn silage in terms of degradation kinetics and mean fiber retention time, while the other residues have worse degradation kinetics than corn, which is due mainly to the elevated undegradable fraction. All the analyzed residues, as well as corn silage, share the same characteristics of fiber passage kinetics.

Phosphorus and bioenergy recovery from anaerobic co-digestion of food waste and corn residues with digested sludge: effect of HRT and pre-treatment methods

AbstractOrganic wastes from the human ecosystem including food waste (FW), agricultural waste and digested sludge (DS) from wastewater treatment can be utilized as valuable materials in anaerobic co-digestion (AcoD) for the dual purpose of bioenergy production and phosphorus (P) recovery through a chemical precipitation process. In this study, AcoD using FW and corn residues (CS) with DS for simultaneous sustainable phosphate release and biogas production were investigated. Different hydraulic retention times (HRT) of 10, 20, and 30 days were investigated, and FW was grinded, while CS pre-treatment methods including physical (FWCS), chemical (FWCS-Chem), and thermal (FWCS-Temp) were considered. The substrates of FW and CS compositions were conducted with a total organic loading of 6 g volatile solids (VS)/L/d (5 FW/1 CS) with a carbon-to-nitrogen ratio (C/N) of 24. The results indicate that FWCS-Chem showed the highest cumulative biogas production simultaneously with P release at HRT 20 days with 7279 L/m3 and 29.67%, respectively. Moreover, the effluent from all digesters exhibited a Mg/P ratio above 1, suitable for struvite precipitation without an external Mg source. Accordingly, FW, FWCS, and FWCS-Chem achieved P recovery rates of 63.64%, 69.75%, and 70.19% at 20-day HRT, with corresponding P contents in solids of 9.45, 9.43, and 8.29%, respectively. These values are comparable to commercial phosphate fertilizer containing 8.80% P. Moreover, incinerating the precipitating solids offers high-quality P concentrations in solids of up to 15.52, 16.32, and 16.31%, respectively. Hence, 20-day HRT was found to be the optimal condition for FW, CS, and DS for anaerobic co-digestion, resulting in the highest biogas production, P release, and maximum financial return for P recovery. Graphical abstract Phosphorus and bioenergy recovery from anaerobic co-digestion of food waste and corn residues with digested sludge.

Integrating solar-driven biomass gasification and PV-electrolysis for sustainable fuel production: Thermodynamic performance, economic assessment, and CO2 emission analysis

Biomass gasification provides a promising pathway for sustainable fuel production. Nevertheless, its development is hindered by lower efficiencies in biomass–to–fuel energy conversion and carbon utilization, along with restricted scale due to economic collection radius. To tackle these challenges, a solar–biomass hybrid gasification system is proposed for sustainable fuel production. The system employs parabolic trough and tower concentrators to generate solar heat, driving the biomass pyrolysis and pyrolysis products gasification reactions to produce bio–solar syngas. The high–density bio–oil and char produced in distributed pyrolysis units can be economically transported to the centralized gasification plant. Moreover, PV–electrolysis water is utilized to generate H2 and O2, which are used to adjust syngas composition and substitute for air separation O2, respectively. Consequently, the energy consumption for water–gas shift, CO2 separation, and air separation units can be reduced. Thermodynamic, economic, and CO2 emission performance are analyzed for a typical case of methanol production using corn residue. The total energy conversion efficiency of the hybrid system can reach 65.01 %, representing an improvement of 6.57 % compared to the conventional biomass gasification system. The fuel production cost is estimated to be $354.1 per ton, falling within the market price range. Additionally, the greenhouse gas emissions to produce unit kg methanol can be reduced by 0.63 kg CO2eq. Furthermore, we analyzed the performance of six representative fuel production scenarios involving different types of biomass feedstocks. Finally, the limitations of this work and the feasibility of its practical applications are discussed. This study offers an innovative approach to bio-solar fuel production, promoting the development of circular bio-economy and the application of sustainable fuel.

Discrete element modelling of the effect of disc angle and tilt angle on residue incorporation resulting from a concave disc

Understanding crop residue behaviour during tillage is critical for improving performance of tillage tools for conservation agriculture. A laboratory experiment was conducted using a concave disc to incorporate corn residue into sandy loam soil. Dynamic attributes, including soil cutting forces and residue incorporation, were measured under different lengths (75, 125, and 200 mm) of corn residue at constant disc and tilt angles. A residue-disc-soil interaction model was developed using discrete element method (DEM). Model parameters were calibrated and validated using experimental data. The validated model was used to predict the dynamic attributes at different disc and tilt angles. Experimental results demonstrated a general increasing trend in draft force (FD) and residue incorporation rate (RI), as the corn residue length increased. The two calibrated model parameters, stiffness of soil particle and stiffness of soil-residue interface were 1.15 × 106 and 13.5 N/m respectively. The validated model had an average relative error of 9.0 % and 18.2 % for predicting RI and FD respectively, as compared with the measurements. Within the angle range of 10° to 30°, the FD and RI decreased as the tilt angle (α) increased, whereas increased as the disc angle (β) increased. The effects of β were more pronounced than those of α. The optimal angles were α = 20°, β = 25° which resulted in a minimum FD and a maximum RI. The results provided new insight into residue-disc-soil dynamics and could be used to guide the selection of disc operating parameters.

Soil hydro-physical variables and crop residues determinate runoff, soil loss, and glyphosate and AMPA concentration in the aqueous phase under simulated rainfall events.

Soil structural degradation and water erosion processes were observed even in no-tillage schemes in the Pampas region. Within these conservation systems, agrochemical application per hectare is one of the highest globally. Thus, this entails a serious risk of water contamination. The objectives of this study were to (1) test the hypothesis that the hydrological dynamics and sediment concentration related to surface runoff were conditioned by soil structure regardless of the presence of maize (Zea mays L.) crop residue and (2) assess the incidence of maize crop residue on glyphosate and aminomethylphosphonic acid (AMPA) concentration in runoff. The soil under study corresponded to Arroyo Dulce Series (Typic Argiudoll silty loam soil). Rain simulations were performed in the laboratory on undisturbed soil samples. Total runoff and infiltration rate were similar between treatments with C(+) and without C(-) maize crop residues (C(+) 1381.40mL and 14.27mm h-1, C(-): 1529.70mL and 21.67mm h-1). The C(-) treatments showed a higher sediment concentration than C(+) (1.58 and 0.42g 100mL-1, respectively). Glyphosate and AMPA average values in runoff were 15.9 and 33.9µg L-1. High variability of the hydro-physical properties and occurrence of soil structure, particularly platy ones, were detected. The hydrological variables were conditioned mainly by the occurrence of platy structures regardless of crop residue presence. Glyphosate concentration was increased in the first runoff event by the presence of corn residues, while AMPA concentrations were higher in the second runoff event in both residue treatments. In this study, maize residue on the soil surface protected the soil from sediment detachment but did not change runoff or infiltration. Thus, the implementation of agricultural management practices that promote vegetative residue cover has shown positive results to erosion.

Survival of Xanthomonas vasicola pv. vasculorum in Soil and in Corn Crop Residues under the Humid Subtropical Climate of Southern Brazil.

Bacterial leaf streak caused by Xanthomonas vasicola pv. vasculorum (Xvv) is an emerging disease in several corn-producing regions around the world. In Brazil, there is a lack of information on the survival of this bacterium in soil and crop residues. Thus, the objective of this study was to determine the survival of Xvv in soil and also in infected corn crop residues under the humid subtropical climate of southern Brazil. The survival of Xvv in soil was initially investigated in sandy and clayey soils maintained at 20, 25 and 30 °C under controlled conditions. The survival of the bacterium under field conditions was studied in artificially infested clayey soil. The survival of Xvv in corn crop residues was investigated in infected residues maintained on the soil surface or buried in the soil at 20 cm deep. Under controlled conditions, regardless of the type of soil, the bacterium survived longer at 20 °C than at higher temperatures. The bacterium survived for 40 days in clayey soil kept at 20 °C and four days in sandy soil maintained at 30 °C. Under field conditions, the survival of Xvv in the soil was only for 48 h and in infected corn crop residues for up to 15 days in the samples maintained on the soil surface. In samples of infected corn residues buried in the soil, the bacterium was only detected at the time the experiment was set up. In general, the results obtained in this study revealed that Xvv survives for a short period of time in soil and in infected corn crop residues under humid subtropical conditions. Therefore, soil and corn residues may not be highly important sources of primary inoculum for the development of bacterial leaf streak on corn crops under these conditions.

Alternative crop residue management practices to mitigate the environmental and economic impacts of open burning of agricultural residues

Deliberate open burning of crop residues emits greenhouse gases and toxic pollutants into the atmosphere. This study investigates the environmental impacts (global warming potential, GWP) and economic impacts (net cash flow) of nine agricultural residue management schemes, including open burning, fertilizer production, and biochar production for corn residue, rice straw, and sugarcane leaves. The environmental assessment shows that, except the open burning schemes, fossil fuel consumption is the main contributor of the GWP impact. The fertilizer and biochar schemes reduce the GWP impact including black carbon by 1.88–1.96 and 2.46–3.22 times compared to open burning. The biochar schemes have the lowest GWP (− 1833.19 to − 1473.21 kg CO2-eq/ton). The economic assessment outcomes reveal that the biochar schemes have the highest net cash flow (222.72—889.31 US$2022/ton or 1258.15–13409.16 US$2022/ha). The expenditures of open burning are practically zero, while the biochar schemes are the most costly to operate. The most preferable agricultural residue management type is the biochar production, given the lowest GWP impact and the highest net cash flow. To discourage open burning, the government should tailor the government assistance programs to the needs of the farmers and make the financial assistance more accessible.

Nutrient Removal from Aqueous Solutions Using Biosorbents Derived from Rice and Corn Husk Residues: A Systematic Review from the Environmental Management Perspective

This review critically analyzed the use of biosorbents derived from rice husks and corn residues for nutrient removal from aqueous solutions. Additionally, this review highlighted the use of such biosorbents in wastewater treatment. Furthermore, novel approaches for sustainable nutrient removal from aqueous solutions were identified. A comprehensive understanding of the implementation of biosorption processes using agro-industrial residues based on corn and rice crops is critical for the sustainable management of residues and water bodies in the world to protect and conserve natural resources. Specifically, the review focuses on the exploration, preparation and application of innovative biosorbents to remove various forms of nutrients such as total nitrogen, total phosphorus, nitrates, ammonium and phosphates from aqueous solution, analyzing the sustainability of treatments applied to biomass, such as thermal transformation or chemical modification to reduce environmental impacts. It was found that 95 to 99% of nitrogen and phosphorus can be removed with biosorbents made from rice husks and corn residues, analyzing approximately 50 scientific articles related to these plant materials. Research opportunities were identified, such as the recovery of removed nutrients for soil improvement, life cycle analysis to assess the concept of zero waste, among other aspects. Finally, a scheme is proposed for the selection and application of sustainable biosorbents for the removal of nutrients from aqueous solutions.

Nitrous oxide emissions from soybean in response to drained and undrained soils and previous corn nitrogen management.

While corn (Zea mays L.)-soybean (Glycine max. Merr. L) is a predominant rotation system in the US Midwest the residual effect of nitrogen (N) fertilization to corn on the following year's soybean and N2O emissions under different soil drainage conditions has not been studied. Our objective was to quantify agronomic parameters and season-long N2O emissions from soybean as affected by N management (0-N and optimum N rate of 135kg N ha-1 as single or split application) during the previous corn crop under drained and undrained systems. Urea was applied to corn, and residual N effects were measured on soybean the following year in a poorly drained soil with and without subsurface tile drainage. Drainage reduced N2O emissions in one of three growing seasons but had no effect on soybean yield or N removal in grain. Nitrogen management in the previous corn crop had no effect on soybean grain yield, N removal, or N2O emissions during the soybean phase. Even though soybean symbiotically fixes N and removes more N in grain than corn, N2O emissions were more than two times greater during the corn phase (mean=1.83kg N ha-1) due to N fertilization than during the soybean phase (mean=0.80kg N ha-1). Also, N2O emissions in the corn years were increased possibly due to decomposition of the previous year's soybean crop residue compared to corn residue decomposition in the soybean years. Tile drainage, especially where wet soil conditions are prevalent, is a viable option to mitigate agricultural N2O emissions.

Pb2+ adsorption on functionalized biochar nanoparticles: Insights from nanoparticle characterization and kinetic‐isotherm analysis

AbstractThere has been an ongoing discussion about whether using functionalized biochar nanoparticles for pollutant removal is practical. The existing uncertainty surrounding functionalized biochar nanoparticles raises questions regarding their effectiveness in unraveling this problem. In this study, functionalized biochar nanoparticles were produced from corn (Zea mays L.) residues and Conocarpus erectus L. wood at 400°C and 700°C using the H2SO4/HNO3 treatment. The synthesized nanoparticles were used to explore their sorption properties for Pb2+. Various adsorption kinetic and isotherm models were evaluated using linear and nonlinear regression techniques. The functionalized biochar nanoparticles originated from wood at 400°C had the largest (80.74 mg g−1) Pb2+ adsorption capacity due to their highest O/C and the most negative zeta potential. In comparison, nanoparticles fabricated from corn residues at 700°C showed the lowest (70.47 mg g−1) Pb2+ adsorption capacity. Pyrolysis temperature affected the sorption process. Functionalized biochar nanoparticles produced at 400°C were more successful in sorbing the pollutant than those fabricated at 700°C. Linear and nonlinear pseudo‐second‐order kinetic models described Pb2+ adsorption kinetics well, indicating the rate‐controlling step. The nonlinear Freundlich model described the equilibrium relationship between adsorbate concentration and capacity, elucidating adsorption site heterogeneity and biochar nanoparticles' affinity for Pb2+. Our study shows that functionalized biochar nanoparticles could help develop procedures for remediating polluted environments.