Utilization Of Stover Research Articles

Challenges of Stover Utilization among Smallholder Dairy Producers in Southern Zambia

Challenges of Stover Utilization among Smallholder Dairy Producers in Southern Zambia

Effects of long-term no-tillage and different stover mulching amounts on soil carbon and nitrogen contents and enzyme activities of carbon and nitrogen cycle in Mollisols.

To understand the effects of different stover mulching amounts in no-tillage on soil carbon and nitrogen contents and enzyme activities, finding a stover mulching amount which can meet the requirement of soil carbon and nitrogen accumulation while maximizing economic benefits, we conducted a long-term conservation tillage field experiment since 2007 in Mollisols area of Northeast China. We analyzed soil carbon and nitrogen contents, enzyme activities and economic benefits under conventional tillage (Control, CT), no-tillage without stover mulching (NT0), no-tillage with 33% stover mulching (NT33), no-tillage with 67% stover mulching (NT67), and no-tillage with 100% stover mulching (NT100) before planting in May 2020. The results showed that compared with CT, NT0 did not affect soil organic carbon (SOC) and total nitrogen (TN) contents, but increased soil organic carbon recalcitrance and decreased the availability of dissolved organic nitrogen (DON) and ammonium nitrogen. Compared with NT0, no-tillage with stover mulching significantly increased SOC contents in 0-10 cm layer and increased with the amounts of stover. In addition, NT67 and NT100 significantly increased SOC stocks, facilitating the accumulation of soil organic matter. The effects of different stover mulching amounts on soil nitrogen content in 0-10 cm layer were different. Specifically, NT33 increased DON content and DON/TN, NT67 increased DON content, while NT100 increased TN content. Compared with CT, NT0 decreased peroxidase (POD) activity in 0-10 cm layer. Compared with NT0, NT33 increased β-glucosidase (βG), cellobiase (CB), 1,4-β-N-acetylglucosaminidase (NAG), polyphenol oxidase (PPO) and POD activities, while NT67 only increased CB, NAG and POD activities in 0-10 cm soil layer, both alleviated microbial nutrient limitation. NT100 increased PPO activity in 10-20 cm layer. NT33 increased carbon conversion efficiency of stover compared with NT100, and had the highest economic benefit. In all, no-tillage with 33% stover mulching was the optimal strategy, which could promote nutrient circulation, boost stover utilization efficiency, improve the quality of Mollisols, and maximize guaranteed income.

Synthesis of silsesquioxanes with methacryloyloxy and phenyl groups using corn stover ash as the major precursor

To address the challenges associated with corn stover utilization and the synthesis of phenyl- and methacryloyloxy-based silsesquioxanes (SQs) with difficulty and poor controllability, the authors present a novel approach that combines advanced biorefining techniques and innovative chemical synthesis methods. Spirocyclic alkoxysilane synthesized from corn stover ash was subsequently utilized for the synthesis of phenylSQs. The resulting phenylSQs were then subjected to fluorine ion-catalyzed rearrangement with 3-(trimethoxysilyl)propyl methacrylate (KH570) to yield SQs containing phenyl and methacryloyloxy functional groups. Through manipulating the ratio of phenylSQs and KH570, the authors successfully achieved a desired ratio of functional groups on individual SQ cages. Optimization of the ratio significantly impacted product collection, with a range of 5.5:1 to 8.5:1 recommended for efficient and effective synthesis. This study represents an important advancement in the field of high-value conversion of biomass, offering an easy means of tailoring the structure of phenyl- and methacryloyloxy-based cage SQs.

Preparation and properties of stover cellulose grafted poly (acrylic acid‐potassium humate) with water‐retention and slow‐release fertilizer

AbstractTo improve the utilization of stover and fertilizer and also save water resources, a degradable slow‐release fertilizer of corn stover cellulose graft poly (acrylic acid‐potassium humate) (CSC‐g‐P(AA‐KHA)) was prepared using corn stover cellulose (CSC), acrylic acid (AA) and potassium humate (KHA) by aqueous solution polymerization. Characterization of CSC‐g‐P(AA‐KHA) with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) techniques provided evidence for the successful preparation. The product prepared exhibited excellent water absorbency (792.89 g·g−1 and 72.69 g·g−1 in deionized water and 0.9 wt% NaCl solution, respectively) and enhanced soil's capacity of water holding and water retention. After 5 cycles, the water absorptivities of CSC‐g‐P(AA‐KHA) in deionized water and 0.9 wt% NaCl solution were 51.71% and 49.97% of their initial water absorption, respectively. The degradation rate of CSC‐g‐P(AA‐KHA) was 32.02% after 50 days. Soil column leaching test and pot experiment demonstrated the slow‐release effect and plant growth promotion of CSC‐g‐P(AA‐KHA). CSC‐g‐P(AA‐KHA) showed desirable application potential in agriculture and is expected to become a functional fertilizer that integrates water absorbing, water‐holding and slow‐release properties.

Life cycle assessment comparison of three typical energy utilization ways for corn stover in China

In order to reduce air and soil pollution caused by open-field burning of stover and improve energy utilization efficiency in rural areas, Chinese government has provided many incentives for bio-energy utilization. But the amount of subsidy was not pegged to the actual environmental benefits of different energy utilization ways of agricultural waste. In this study, processed based life cycle assessment (LCA) method is used to investigate and compare the environmental impacts of three most common stover utilization ways, including biogas, stover pellets and stover gasification. The inventory analysis results are assessed by ReCiPe mid-point (H) method and end-point (H) damage evaluation, respectively. Based on the uncertainty analysis with Monte Carlo method, the compared results are expressed in probability and discussed, which shows the stover gasification utilization has more damage on the environment. Compared with the utilization of stover biogas, the utilization of stover pellets has less damage on resource depletion, but it is more harmful to human health and ecosystem. The materials used, transportation, equipment operation energy consumption, and stover utilization efficiency are found as the main parameters that affect the LCA results.

EFFECTS OF SOURCE AND LEVEL OF NITROGEN ON THE UTILIZATION OF SORGHUM STOVER BY YANKASA RAMS

The effects of cotton seed cake (CSC) or urea in supplying either 12% or 16% crude protein on sorghum stover utilization by Yankasa rams was studied for twelve weeks, using a 2 x 2 factorially designed experiment. Nutrient intake, digestibility, weight gain and feed conversion ratio (FCR) were monitored. In vitro volatile fatty acid (VFA) and ammonia-nitrogen (NH,-N) concentrations were also determined. The result of the study indicated that the source and/or level of nitrogen (or crude protein) significantly (P<0.05) affected crude protein intake (CPI), digestible crude protein intake (DCPI) and in vitro NH,-N concentration. Total feed intake, live weight gain (LWG), FCR and DCPI were significantly (P<0.05) affected by source x level interaction. Acid detergent fibre (A DF) and neutral detergent fibre (NDF) intakes, CP, ADF and NDF digestibilities, digestible ADF and NDF intakes, stover intake and in vitro VFA concentration were not significantly (P>0.05) affected by either main effects of CP source and level or their interaction. The rams on the 16% CSC and 12% urea ration gained more weight and had lower FCR than those on the 12% CSC and 16% urea. The 16% CSC ration gave the best result in terms of sorghum stover supplementation. The 12% urea treatment which also had a good result in terms of weight gain and FCR could also be recommended for use.

Simulated Biomass Sorghum GHG Reduction Potential is Similar to Maize

Policy support for cellulosic biofuels is contingent on their achieving much greater reductions in life-cycle greenhouse gas emissions than corn starch ethanol. Biomass sorghum has been suggested as a genetically and agronomically tractable feedstock species to augment near-term cellulosic feedstock production. This study used DayCent modeling to investigate biomass sorghum production emissions relative to corn with and without stover utilization at 3,265 across the rainfed United States. Sorghum produced greater average feedstock dry matter (15.6 ± 1.4 vs 14.8 ± 2.2 Mg ha-1 yr-1) and slightly lower estimated ethanol energy yields (10.6 ± 1.0 vs 11.8 ± 2.9 MJ m-2 yr-1) as corn grain with 75% stover collection. The high biomass removals in both the sorghum and corn stover scenarios led to soil organic carbon losses on 90 and 100% of sites, respectively. Average feedstock production emissions intensities were similar between sorghum and corn with 75% stover removal (17.6 ± 2.8 vs 18.8 ± 3.0 g CO2e MJ-1), but were notably lower under sorghum for sites in the southwestern study region (13.6 ± 3.0 vs 22.5 ± 3.1 g CO2e MJ-1). These results suggest that biomass sorghum produces cellulosic feedstock with similar emissions to corn grain and at current yield levels is unlikely to meet the Renewable Fuel Standard emissions reduction threshold for cellulosic biofuels.

Characterization and Localization of Dynamic Cell Wall Structure and Inorganic Species Variability in Harvested and Stored Corn Stover Fractions as Functions of Biological Degradation

Traditional approaches for corn stover utilization create an inhomogeneous, whole plant mixture that does not achieve performance and cost targets for biofuel production. The improvement of conversion performance will require one to gain a fundamental understanding of the inherent cellular structure and ash content in the process. This study investigated cellular structure and inorganic species contents with scanning electron microscopy (SEM), advanced energy dispersive X-ray spectroscopy (EDS), and wet analytical chemistry methods. These techniques provided a complementary means to understand variability within the dynamic cell walls and the distributions of inorganic species at the anatomical and tissue scales for various corn stover fractions. Material properties were investigated for bales from in-field storage scenarios ranging from mild to severe biological degradation. Results show that stem, cob, and leaf tissues all maintained cell wall and surface structure integrity after mild biological degradation. However, severe degradation (with spontaneous heating) caused remarkable structural distortion and cell wall shrinkage for all tissue types. Inorganic species quantitation data shows that three fractions of severe degradation have slightly reduced total ash, 4.91% vs 3.92% for cobs, 7.28% vs 5.98% for stems, and 14.21% vs 13.07% for leaves. Silica contents also decreased (2.67% vs 1.83% for cobs, 3.60% vs 2.89% for stems, and 9.72% vs 8.48% for leaves), likely due to the loss of extrinsic inorganic species. SEM-EDS inorganic species mapping of stems demonstrated that severe biological degradation caused the translocation of the dominant silicon elements from pith to rind tissue as well as a reduction of potassium in the stem. These findings offer detailed knowledge of feedstock variability at the anatomical tissue level that can be used to inform the development of advanced processing strategies. Innovative storage and selective fractionation processes have the potential to manage low-quality fractions/tissues and remove unfavorable inorganic species for efficient conversion of corn stover as well as other lignocellulosic biomass.

Enhancing enzymatic hydrolysis of corn stover by twin-screw extrusion pretreatment

Efficient and cost-effective hydrolysis of cellulose and hemicellulose into monosaccharide is the crucial and challengeable step for corn stover utilization. In this study, twin-screw extrusion pretreatment changed the particle size distribution and spatial structure of corn stover samples, but had basically no effects on their chemical structure. Cellulose content of CS-DW and CS-DW-GNa increased, but hemicellulose content and crystalline index decreased with extrusion pretreatment. Glucose yield of CS-DW increased from 25 g/L of CS with 48 h hydrolysis time to 34 g/L by 36 h of hydrolysis time, and glucose yield of CS-DW-GNa increased to 45 g/L with 24 h hydrolysis time. Meanwhile, xylose yield of CS-DW and CS-DW-GNa increased from 19 g/L of CS (48 h) to 27 g/L (36 h) and 40 g/L (24 h), respectively. These results provide good guidance for improving the conversation of lignocelluloses to monosaccharide for further utilization.

Slow Pyrolysis Performance and Energy Balance of Corn Stover in Continuous Pyrolysis-Based Poly-Generation Systems

In order to analyze pyrolysis performance and energy balance of corn stover utilization in continuous pyrolysis, the continuous carbonization tests were carried out on a poly-generation unit of biochar, gas and liquid developed by our research team. Corn stover was naturally dried and crushed to length of 4-7mm, and the heating thermometers are 450, 550, 650℃, the physical and chemical properties, yield rate and influence of technological parameters on them were analyzed. On this basis, the system heat transfer calculation and energy balance analysis were done. Results show that the quality of corn stover char are affected tremendously by pyrolysis temperature and material residence time, the residence time generally should be not less than 30 min. The HHV of pyrolysis gases reach about 20 MJ/Nm3 at pyrolysis temperature of 550 and 650℃. In terms of energy balance, biochar at 47.88% accounts for most of the enthalpy of products, followed by pyrolysis gas (36.17%), and wood tar and light oil, accounting fo...

Construction of recombinant Yarrowia lipolytica and its application in bio-transformation of lignocellulose

ABSTRACT Lignocellulose is a polysaccharide and an abundant biomass resource that widely exists in grains, beans, rice, and their by-products. Over 10 million tons of lignocellulose resources and processing products are produced every year in China. Three recombinant Y. lipolytica strains with cellulase (β-glucosidase, endoglucanase and cellobiohydrolase) were constructed. The enzymatic activities of these enzymes were 14.181 U/mL, 16.307 U/mL, and 17.391 U/mL, respectively. The whole cell cellulases were used for a stover bio-transformation. The celluloses in the stover were partly degraded by the cellulases, and the degradation products were transformed into single cell protein (SCP) by the Y. lipolytica cells. After 15 d of fermentation with the whole cell cellulases, the protein content of the maize stover and the rice straw reached 16.23% and 14.75%, which increased by 168.26% and 161.52% compared with the control, respectively. This study provides a new stage for the efficient utilization of stover in the feed industry.

Determinants of maize stover utilization as feed, fuel and soil amendment in mixed crop-livestock systems, Ethiopia

Crop residues have several uses in smallholder mixed crop-livestock systems. This paper examines determinants of households’ maize stover use as livestock feed, fuel and soil amendment in maize-based systems in Ethiopia. In these systems maize stover is primarily used as feed (56% of biomass) and fuel (31%), with the feed use share negatively associated with maize production potential. We develop a Seemingly Unrelated Regression model to capture the interdependence of crop residue uses. Results show extension training on crop residue retention in the field results in more residue use for soil amendment and less for feed. Farmers with more livestock tend to use more residues for feed and less for soil mulch. Cropping pattern, farm size, agro-ecology and crop residue production also influence crop residue utilization. Conservation agriculture interventions have implications for crop residue use and need to consider access to information, cropping patterns, resources endowments and other socio-economic factors in their development and targeting.

Utilization of stover from six improved dual-purpose Groundnut(<i>arachis hypogaea l.</i>) Cultivars by West African dwarf sheep

The study was set up to evaluate fodder from six dual-purpose groundnut (Arachis hypogaea L.) cultivars for animal performance and rumen dry matter (DM) degradability characteristics. Thirty-six West African dwarf (WAD) sheep were used to evaluate the utilization of groundnut stover from six improved dual-purpose cultivars (M170-80I; M554-76; M572-80I; RMP-12; UGA-2; UGA-5) as sole diets over 70 d. Rumen DM degradability characteristics were studied using four WAD sheep in a completely randomized design. Dry matter, crude protein (CP), neutraldetergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and metabolisable energy (ME) contents were similar while, cultivar RMP-12 recorded the highest (P < 0.05) hemicellulose (64 g/kg DM and cellulose (396 g/kg DM) contents. Organic matter (58.1 to 71.9 g/kg metabolic weight (W0.75)/d) and NDF (32 to 41 g/kg W0.75/d) intake were significantly different (P < 0.05). The digestibility of DM (508 to 623 g/kg DM), OM (498 to 626 g/kg DM) and CP (488 to 588 g/kg DM)differed (P < 0.05). Similarly, NDF digestibility (488 to 635 g/kg DM) and ADF digestibility (406 to 572 g/kg DM) were significantly different (P < 0.05). Nitrogen balance (3.0±0.98 g/d) was similar (P > 0.05) among cultivars, whereas available protein ranged (P < 0.05) from 2.5 g d-1 for RMP-12 to 29.0 g d-1 for M170-80I. Liveweight changes (LWC) varied between 6 g/d weight loss by sheep on UGA-2 fodder and 46 g/d in M170-80I. Soluble fraction (a) differed significantly (P < 0.05)ranging between 197 and 351 g/kg DM, while degradable fraction (b) and rate of degradation of b (c) were not significantly different. The 48-h degradation (501 to 596 g/kg DM), potential degradability; PD (584 to 687 g/kg DM) and effective degradability; ED (415 to 489 g/kg DM) varied (P < 0.05). Groundnut stover could be fed as sole diets or supplements to WAD sheep, and the cultivars ranked in decreasing order of stover quality as: M170-80I > UGA-5 > M572-80I = UGA-2 > 50 RMP-12 > M554-76. While sole-feeding groundnut has been illustrated to result in improvedweight gain in WAD sheep, it might also be economical to use the fodder as a supplement.

Kinetic Study of Dilute Nitric acid Treatment of Corn Stover at Relatively High Temperature

AbstractCorn stover was hydrolyzed using dilute nitric acid at 150 °C. Several concentrations of HNO3 (0.2, 0.4 and 0.6 wt‐%) and reaction times (0–60 min) were evaluated. The kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, arabinose, acetic acid, and furfural in the hydrolysates were determined. The hydrolysates obtained from corn stover can be used to produce methane by an anaerobic fermentation process. Thus, the hydrolysis process of corn stover using dilute nitric acid can be conceived as the first stage of an integrated strategy for corn stover utilization.

An Analysis of the Relationship between Demand for Corn Stover as an Ethanol Feedstock and Soil Erosion

An analysis of corn stover utilization as an energy feedstock was conducted for southern Minnesota to determine if any economic incentive existed to encourage corn stover harvest beyond USDA-NRCS tolerable soil loss levels. Results indicate that only if the number of conversion facilities in the region exceeded 10 that there would exist an incentive to harvest stover in a manner that would violate tolerable soil loss levels under current tillage practices. If all farms switched to no-till, little to no economic incentive would exist unless the number of conversion facilities exceeded 19.

Kinetic studies of hemicellulose hydrolysis of corn stover at atmospheric pressure

The object of this work was to study the xylose production by hydrolysis of corn stover with diluted sulfuric acid at 100 °C. Several concentrations of H2SO4 (2%, 4% and 6% w/w) and reaction time (0–300 min) were evaluated. Kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose and furfural in the hydrolysates were found. Optimal conditions for hydrolysis were 5.5% H2SO4 at 100 °C for 60 min; under these conditions, 86.7% of xylose yield and 2.82 g/g selectivity were attained, leading to liquors containing up to 18.73 g/l xylose, 6.64 g/l glucose and 0.63 g/l furfural. The models could be successfully used to predict the concentrations of xylose, glucose and furfural within 0–300 min under experimental acid concentrations. Furthermore, the hydrolysis process of corn stover using dilute acid could be conceived as the first stage of an integrated strategy for corn stover utilization.

Effects of Hybrid and Maturity on Maize Stover Ruminal Degradability in Cattle Fed Different Diets

The effect of maize hybrid (Suco and Dekalb 765, DK 765), maturity stage (milk, R3 and 1/2 milk line, R5) and animal diet (Diet 1: 70% lucerne hay+30% maize silage; Diet 2: 50% maize silage+20% sunflower meal+30% maize grain) on ruminal stover dry matter (DM) degradability was studied. Additionally, morphological and chemical plant composition was evaluated. Fodder samples ground at 2 mm were incubated in three Holstein steers (400 kg body weight) using the in situ technique. Ruminal degradation kinetics was studied and the effective degradability (ED) was estimated for an assumed kp of 5%/h. The in situ data was analyzed in a complete randomized block design with the animals as blocks. Significant interactions between hybrid×diet and maturity×diet on kinetic digestion parameters were detected. In Diet 1, hybrids did not differ in degradable fraction, kd or ED, although a minor difference (p<0.05) in the soluble fraction was found (25.5 and 23.2% for Suco and DK 765, respectively). In Diet 2, the DK 765 had greater degradable fraction (p<0.001) but smaller (p<0.01) kd than Suco, without differences in the soluble fraction or in ED. Anticipating the harvest increased ED of stover from 37.5% in R5 to 44.6% in R3 (average values across hybrids and diets) due to the increase (p<0.001) in the soluble fraction (R5: 22.6%, R3: 28.8%). It is concluded that hybrids had similar stover in situ DM degradability and that soluble fraction represent the main proportion of degradable substrates. Advancing the date of harvesting may not improve the in situ DM degradability of whole maize plant silage since the increase in stover quality is counteracted by the depression in the grain-to-stover ratio. The diet of the animal consuming silage might not improve stover utilization either. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 11 : 1619-1624)

DRY MATTER YIELD, IN VITRO DIGESTIBILITY, PERCENT PROTEIN, AND MOISTURE OF CORN STOVER FOLLOWING GRAIN MATURITY

Past research and practical experience have shown that the stover of corn (Zea mays L.) can be used successfully as a roughage and energy source for ruminant animals. The present paper describes three experiments designed to study agronomic aspects of stover utilization. Specifically, the objectives were: (1) to study the rate of moisture loss from stover before and after grain harvest; (2) to measure the variability among commercial hybrids in stover quality and yield; and (3) to examine the relationships between grain and stover yield, and between grain and stover moisture percentage. Averaged across hybrids, 38% of the above-ground dry weight of corn was stover, including stalk, leaf, husk, and shank. At grain maturity, all adapted commercial hybrids produced stover dry matter yields in excess of 4,500 kg/ha with an in vitro digestible dry matter (IVDDM) in excess of 52%. Lower yields of stover dry matter and stover IVDDM were evident for certain nonadapted, or nonrecommended hybrids. Within recommended hybrids there was a nonsignificant correlation between grain yield and stover yield. Percent IVDDM of the stover declined at a rate of 1.5%/wk following grain physiological maturity. Protein content of stover averaged 4.5% and was unaffected by hybrid or date of harvest. No relationship was evident among hybrids between percent stover moisture at harvest and percent grain moisture. The mean percent stover moisture, after adjustment by covariance to 30% grain moisture, was 57.8 with a standard deviation across hybrids of 11.4%. Stover dried at an average rate of 1.0 g water loss per 100 g fresh weight per day during the grain maturation period. Differences among hybrids in percent stover moisture at a common grain moisture were primarily a result of differences in the date at which stover began to dry below its initial moisture content of 80%. Grain harvest with a standard corn combine increased the drying rate of stover to approximately 1.5 g water per 100 g fresh weight per day during the period after grain maturity.