Search

This study aims to promote the full-value utilization of corn stover. Data sources were selected as the China Knowledge Infrastructure database and the Web of Science. Visualization software was used to draw knowledge graphs in the field of corn stover use. The current status of research and trends were summarized to analyze the key generic technologies of corn stover use. Two stages were divided in the utilization of corn stoves: 1990-2007 and 2008-2022. In the latter stage, the research system of corn stover use was gradually formed using fertilizer and feed that was supplemented by fuel. A literature review found that the research on corn stover use roughly experienced three phases of hot spot migration, each of which lasted about 10 years. The research was focused mainly on stover returning during the period 1990-2000; The focus of the research was straw returning to the field, straw energy, and feed use during the period 2001-2010; The utilization of corn stover was diversified to gradually form during the period 2011-2022. The utilization of corn stover was achieved mainly in the fields of stover returning and biomass energy production. According to the knowledge graph, the hot directions of corn stover use included biomass energy production, land improvement and protection, animal husbandry development, and feed production. Finally, the knowledge engineering and induction show that there were still some bottlenecks in the technology of corn stover use, such as delayed collection and transportation, low quality of returning, immature technology of stover feed, high cost, and low added value of energy technology. Driven by the important national demand for the utilization of agricultural waste resources, 13 key generic technologies were summarized for the full-value utilization of corn stover, including intelligent control and management of agricultural machinery and equipment, digital agriculture, high-quality field-returning, fieldreturning under the local conditions, sealed storage, high-yield cellulose strain of screening, selection, and breeding of efficient microbial strains for lignin degradation, strain matching and enzyme application, high-efficiency biomass energy conversion, stover cellulose to ethanol, lignocellulosic sugar, stover cultivation substrate preparation, and bio-based material manufacturing [ABSTRACT FROM AUTHOR]

The development of accurate bioenergetic models, that simulate scenarios for decision making and policy planning contributions, has become a necessity in the actual climate crisis context. The objective of this work is to develop a multicriteria methodology to evaluate scenarios for assessing a region's bioenergetic potential and determining optimal location of biopower plants. This method utilizes a geographic information system that incorporates local biomass distribution, crop harvest statistics, detailed yield data, preference and exclusion maps. The approach examines the current local use of residues in the context of long-term soil preservation, employing sustainable residue removal. When it is applied to the Province of Córdoba, Argentina, specifically assessing main agricultural harvest residues, the model identifies 1.8 million tn/year of theoretical residues, primarily from corn and soybean, revalorizing only 4.1% of the available harvest agricultural residues. When employing the most commonly used approaches in the literature, which involves average crop yield values for extensive regions, our results show an underestimation of theoretical biomass up to 26%. This makes it essential to incorporate greater detail in the modeling. After optimizing five biopower plants, each with a collection radius of 60 km, it becomes possible to convert 59% of these residues into bioenergy, generating 2.3 GWh/year, covering up to 23.3% of Córdoba's annual electricity demand. The novelty of this research resides in the development of a high detailed multicriteria methodology, which facilitates the fast simulation of scenarios to identify optimal biopower plant locations, applicability to different biomass types and bioenergy forms for extensive regions. [ABSTRACT FROM AUTHOR]

BackgroundMaize stover is an important source of crop residues and a promising sustainable energy source in the United States. Stalk is the main component of stover, representing about half of stover dry weight. Characterization of genetic determinants of stalk traits provide a foundation to optimize maize stover as a biofuel feedstock. We investigated maize natural genetic variation in genome-wide association studies (GWAS) to detect candidate genes associated with traits related to stalk biomass (stalk diameter and plant height) and stalk anatomy (rind thickness, vascular bundle density and area).ResultsUsing a panel of 942 diverse inbred lines, 899,784 RNA-Seq derived single nucleotide polymorphism (SNP) markers were identified. Stalk traits were measured on 800 members of the panel in replicated field trials across years. GWAS revealed 16 candidate genes associated with four stalk traits. Most of the detected candidate genes were involved in fundamental cellular functions, such as regulation of gene expression and cell cycle progression. Two of the regulatory genes (Zmm22 and an ortholog of Fpa) that were associated with plant height were previously shown to be involved in regulating the vegetative to floral transition. The association of Zmm22 with plant height was confirmed using a transgenic approach. Transgenic lines with increased expression of Zmm22 showed a significant decrease in plant height as well as tassel branch number, indicating a pleiotropic effect of Zmm22.ConclusionSubstantial heritable variation was observed in the association panel for stalk traits, indicating a large potential for improving useful stalk traits in breeding programs. Genome-wide association analyses detected several candidate genes associated with multiple traits, suggesting common regulatory elements underlie various stalk traits. Results of this study provide insights into the genetic control of maize stalk anatomy and biomass.

Static facultative composting is one of the most widely-used, cost-effective, lightweight, and simple technologies to utilize local resources in modern agriculture. More than 60% of livestock and poultry manure (especially pig manure) can be treated using static composting. Static facultative composting can also create an aerobic environment with low porosity and limited depth of air diffusion within the heap, resulting in the low metabolic activity of microorganisms. Degradation of organic matter can be inevitably delayed, due to the long fermentation cycles, low fermentation temperatures, incomplete harmlessness, and low product maturity. Alternatively, the straw can be added to adjust the physical structure, oxygen content, and C/N ratios of the heap, in order to effectively improve the rot degree of static facultative compost products for the short rot cycle. This study aims to explore the effects of straw control on the maturity and microbial community structure of static facultative composting, especially on pathogenic bacteria. The corn straw was taken to regulate the physical structure and C/N ratio of the pile. A 90-day static facultative composting experiment was conducted using traditional natural fermentation. A systematic investigation was made to clarify the maturation index, fecal coliforms, and microbial community structure in the static facultative composting. The composting device was set as a 100 L flanged iron hoop bucket. Two treatments were set up in total. The control group was set without pig manure to label as the P treatment. The mixed compost of pig manure and corn straw was labeled as the PC treatment. The wet base mass ratio of 4:1 was selected without ventilation and heap turning. The results showed that the straw regulation increased the porosity of the compost (increased by 19.41%), and then promoted the diffusion of oxygen to the interior of the compost for the better degradation of organic matter by aerobic microorganisms. Specifically, the contents of phytotoxic substances were reduced (such as NH4+ -N and DTN) to improve the compost maturity. The seed germination indexes were 40.84% (P) and 114.60% (PC), respectively, in the two groups of compost products. As such, the compost maturation was accelerated during this time. The number of fecal coliforms reached the hygienic safety standard after 30 to 40 days of natural fermentation. Furthermore, the activity of fecal coliforms depended on the temperature of the pile, NH4+ -N, and organic acid content. The corn straw was added to improve the diversity of bacteria and synergistic effect. Firmicutes, Actinobacteria, Proteobacteria, and other phylum related to lignocellulosic degradation were the dominant microbial phylum in the reactor, where the aerobic, facultative, and anaerobic microbial stratification was formed from the aerobic to anaerobic bacteria from the top to the bottom. Therefore, the corn straw regulation can be expected to increase the aerobic area of the pile in the process of static composting. The harmless and mature degree can be promoted in the static composting of pig manure. The finding can provide the theoretical basis and technical standardization support for the static composting of livestock and poultry manure. [ABSTRACT FROM AUTHOR]

Introduction: To comprehend soil P transformation and crop P uptake, it is necessary to understand how the long-term substitution of mineral fertilizers with stover or biochar affects soil properties and P forms. However, the effects of largescale continuous stover or biochar application on soil P forms and fractions and the response of P uptake by corn are largely unknown. The purpose of this study was to investigate the role of stover and its biochar in the variation of P forms and Hedley-P fractions. Methods: A five-year field experiment in brown soil was carried out using the following treatments: non-fertilizer (CK), chemical fertilizer (NPK), chemical fertilizer + corn stover (SNPK), and chemical fertilizer + biochar (CNPK). Hedley fractionation and 31P nuclear magnetic resonance spectroscopy were used to determine P compounds. Results and discussion: The greatest increases in P uptake occurred during the CNPK treatment, specifically orthophosphate and Resin-P, and coincided with increases in total inorganic P and Hedley-P fractions. On the other hand, total organic P accumulation was found to be highest in the SNPK treatment, as was total inositol hexakisphosphate and orthophosphate diester accumulation. Treatments with SNPK and CNPK significantly increased adenosine monophosphate and DNA. However, no difference was found between NaHCO3-Pi and NaOH-Pi of the NPK, SNPK, and CNPK treatments. Decreasing chemical fertilizer and partially replacing it with biochar in brown soil may increase crop P uptake by degrading applied organic P forms and multiplying inorganic P forms. [ABSTRACT FROM AUTHOR]

Incorporating woody legumes, e.g. Sesbania sesban (L.) Merr. in maize production systems can improve maize yield and increase quantity and quality of fodder (maize stover, browse). We compared sole maize with three maize-Sesbania alley cropping treatments: hedgerows cut at 75 cm aboveground to facilitate maize planting, and hedgerows cut biannually to 50 cm or 75 cm. Maize grain yield declined significantly (P < 0.05) with hedgerows (5.6 Mg ha−1 without vs 3.0 Mg ha−1 for biannual cutting and 1.9 Mg ha−1 for one cut). Browse (leaf, twig) yield increased significantly (P < 0.05) from 1.7 Mg ha−1 to 6 Mg ha−1 with biannual cutting. Total fodder yield increased significantly (P < 0.05) to 7.6 Mg ha−1 with biannual cutting vs 3.3 Mg ha−1 when cutting once and 3.1 Mg ha-1 without hedgerows. With increased fodder yield under biannual cutting, nutritional yields and crude protein content increased and fibre contents decreased significantly (P < 0.05), indicating improved nutritional value for livestock. Results indicated the importance of stored carbohydrates over current photosynthate for regrowth in plants cut severely. Maize-Sesbania alley cropping with biannual cutting to 75 cm appeared most parsimonious for producing maize grain and fodder. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Knowledge about how on-farm management decisions influence maize residue quantity and quality is limited but necessary to better manage the effects of residue on cropping systems carbon, nutrient turnover, and water dynamics. Our objectives were to i) Quantify the interactive effects of previous crop, nitrogen (N) fertilizer rate, plant density, and hybrid on maize residue quantity and quality characteristics, and ii) Explore relationships and potential trade-offs between residue attributes and grain yield to aid decision making. Experiments were carried out in central Iowa, USA in 2021 and 2022. We evaluated three commercial hybrids across three N fertilizer rates (0, 146, 336 kg N ha−1), and three plant densities (3.6, 7.5, 11.3 plants m−2) in fields with maize or soybean as the previous crop, totaling 54 replicated treatments. Biomass samples were collected at physiological maturity, and 12 residue-related attributes were assessed together with the final grain yield. The experimental factors generated a large variability in maize grain yield (1.5–15.4 Mgha−1), residue amount (2.6–14.1 Mg ha−1), residue CN ratio (33–130), residue N (11–167 kg N ha−1), and residue lignin concentration (1.0–3.6%). Nitrogen fertilizer explained most of the variability in residue quantity and CN ratio while plant density explained most of the variability in residue biochemical composition. Significant interactions among studied factors on residue attributes were few and mostly related to hybrids by plant density and previous crop by N rate interactions. Our results indicated that the higher the grain yield, the higher the residue quantity (r = 0.79), the residue lignin concentration (r = 0.46), and the lower the residue CN ratio (r = −0.51). Grain yields lower than 8 Mg ha−1 generated comparatively higher residue quantities (grain harvest index < 0.50), while the opposite occurred at grain yields above 8 Mg ha−1. Management practices that resulted in high grain yields generated residues with low CN ratio but high lignin concentration, indicating a tradeoff in residue quality. The observed large effects of management on residue quality and quantity imply that there are opportunities to manipulate residue attributes via management for maximizing profitability and soil health. • Management practices generated 1.4–15-fold variability in residue attributes. • Nitrogen fertilizer explained most of the variation in residue quantity and CN ratio. • Plant density explained most of the variation in residue biochemical composition. • Practices that increased grain yield resulted in a low residue CN ratio but high lignin concentration. [ABSTRACT FROM AUTHOR]

Global demand for bio-based energy is on the rise and so is research on bioenergy feedstock productivity. In this study, seven cultivars of grain sorghums ('301/41,' '304/5,' '319/8,' '319/22,' '341/10,' '341/120,' and '366/58') which developed in the drylands of Texas-US were evaluated in the Mid-Atlantic, a relatively wet region. The objective of the study was to evaluate crop response to phosphorus, productivity in the Mid-Atlantic, and its potential for bioethanol production. Seed yield, starch, and element content, stover biomass, forage quality, and whole-plant bioethanol yield were determined. Phosphorus had no effect, and only cultivars were compared. Cultivar showed differences in seed and stover yield, seed quality attributes, and potential bioethanol yield. Cultivar '366/58' produced the greatest seed yield averaged at 4934 kg ha −1 yr −1 while '301/41' and '341/10' produced the least averaged at 2,743 and 2,968 kg ha −1, respectively, Stover yield across years ranged from 6,798 to 13,365 kg ha −1, and the whole plant estimated bioethanol ranged from 3,159 to 5,770 L ha −1. The stover had appreciable forage quality, including a 49 g kg −1 crude protein, sufficient for animal maintenance needs. Up to 96 kg N ha −1 and 211 kg K ha −1 were removed from harvested stover, an issue of concern for crop fertilizer management strategy and sustained production. [ABSTRACT FROM AUTHOR]

Lignocellulolytic white-rot fungi allow the bioconversion of agricultural wastes into value-added products that are used in a myriad of applications. The aim of this work was to use corn residues (Zea mays L.) to produce valuable products under solid-state fermentation (SSF) with Pleurotus ostreatus. White-rot fungus P. ostreatus was isolated from maize silage (MS) and thereafter it was inoculated on MS as substrate and compared with maize stover (MSt) and maize cobs (MC) to determine the best lignocellulosic substrate for the production of lignocellulolytic enzymes and extracellular protein. The MS gave the highest productivity of CMCase (368.2 U/mL), FPase (170.5 U/mL), laccase (11.4 U/mL), and MnPase (6.6 U/mL). This is compared to productivity on MSt of 222 U/mL, 50.2 U/mL, 4.55 U/mL, and 2.57 U/mL, respectively; and productivity on MC at the same incubation period as 150.5 U/mL, 48.2 U/mL, 3.58 U/mL, and 2.5 U/mL, respectively. The levels of enzyme production declined with increasing incubation period after 15 and 20 days using MS and MC, respectively, as substrates. Maximum liberated extracellular protein content (754 to 878 µg/mL) was recorded using MS, while a low amount (343 to 408 µg/mL) was liberated with using MSt and MC. [ABSTRACT FROM AUTHOR]

Abstract Background Maize stover is an important source of crop residues and a promising sustainable energy source in the United States. Stalk is the main component of stover, representing about half of stover dry weight. Characterization of genetic determinants of stalk traits provide a foundation to optimize maize stover as a biofuel feedstock. We investigated maize natural genetic variation in genome-wide association studies (GWAS) to detect candidate genes associated with traits related to stalk biomass (stalk diameter and plant height) and stalk anatomy (rind thickness, vascular bundle density and area). Results Using a panel of 942 diverse inbred lines, 899,784 RNA-Seq derived single nucleotide polymorphism (SNP) markers were identified. Stalk traits were measured on 800 members of the panel in replicated field trials across years. GWAS revealed 16 candidate genes associated with four stalk traits. Most of the detected candidate genes were involved in fundamental cellular functions, such as regulation of gene expression and cell cycle progression. Two of the regulatory genes (Zmm22 and an ortholog of Fpa) that were associated with plant height were previously shown to be involved in regulating the vegetative to floral transition. The association of Zmm22 with plant height was confirmed using a transgenic approach. Transgenic lines with increased expression of Zmm22 showed a significant decrease in plant height as well as tassel branch number, indicating a pleiotropic effect of Zmm22. Conclusion Substantial heritable variation was observed in the association panel for stalk traits, indicating a large potential for improving useful stalk traits in breeding programs. Genome-wide association analyses detected several candidate genes associated with multiple traits, suggesting common regulatory elements underlie various stalk traits. Results of this study provide insights into the genetic control of maize stalk anatomy and biomass.

With South Korea’s limited capability of feed production because of its relatively small cultivable area, the country is pushed to depend on foreign feed imports despite the immensely fluctuating price of corn. Hence, intensive efforts to increase the total cultivable area in Korea like extending of farming to mountainous area is being practiced. Corn was planted in Goesan County, a mountainous area in the country. Grain and stover were harvested separately in three harvest periods: early-harvest (Aug 8), mid-harvest (Aug 18), and late-harvest (Aug 28). The nutrient composition such as dry matter (DM), crude protein (CP), crude fat (EE), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and non-fibrous carbohydrates (NFC) was determined after harvest. Effective degradability (ED) of the major nutrients (DM, NDF, ADF, and CP) were measured through in vitro fermentation of rumen fluid from Hanwoo (Korean cattle). pH, ammonia-N concentration, volatile fatty acid (VFA) concentration, and gas production were periodically measured at 0, 3, 6, 12, 24, 48, and 72 h. Corn grain showed higher nutrient content and ED than stover. It also had higher gas production but its pH, ammonia-N, and total VFA concentration were lower than corn stover. The best nutrient composition of corn grain was observed in early-harvest (high CP, EE, NDF, OM, NFC, and low ADF). Early-harvest of corn grain also had high effective degradability of dry matter (EDDM), effective degradability of neutral detergent fiber (EDNDF), effective degradability of acid detergent fiber (EDADF), and total VFA concentration. On the other hand, the best nutrient composition of stover was observed in mid-harvest (high DM, CP, NDF, and low ADF). EDDM, EDNDF, and EDADF were pronounced in early-harvest and mid-harvest of stover but the latter showed high total VFA concentration. Hence, early and mid-harvested corn stover and grain in a mountainous area preserved their nutrients, which led to the effective degradation of major nutrients and high VFA production.

This study aims to propose a feasible production technology for the organic fertilizer or soil amendments using the small-scale compost decomposing with local straws and livestock manure. The technical procedure included the straw silkization, material mixing, compression molding, and small-scale compost decomposing. The compost production was transformed from transporting materials to moving equipment, from decomposing and then forming to bagging and then decomposing. The fertilizer production technology can contribute to enhance the local utilization rate of agricultural wastes from small and medium-sized scattered farmers, as well as the mechanization during composting and decomposing effects. The appropriate fertilizer source material ratio and compression ratio were selected under the different material moisture content to prevent water pollution of livestock manure. The special microbial compound agents were added to control the maturity time, and thereby regulate the release of odorous gases. The corn stalks and cow dung were used as fertilizer sources. The seed germination index (GI) was selected as the detection index for the maturity effect of composting. The experimental factors were set for the small-scale compost production, where the key process parameters included the ratio of fertilizer source materials, material moisture content, compression ratio, application amount of microbial agents, and maturity time. A single factor experiment was conducted to determine the appropriate range of experimental factors. A better maturity effect of small-scale compost fertilizer was achieved, where the critical value of applied microbial agent was 0.5‰, the fertilizer source material ratio was 15% to 35%, the material moisture content was 45% to 60%, the compression ratio was 25% to 50%, and the maturity time reached 24 days. A combination experiment of ternary quadratic regression and orthogonal rotation was performed to optimize the influence of key process parameters on the maturity effect of compost fertilizer. A regression model was established between the seed germination index and various factors. The analysis showed that the primary and secondary order for the influence of various factors on the seed germination index was: material moisture content > compression ratio > fertilizer source material ratio. There were significant effects on seed germination index (P<0.05) in the correlation of fertilizer source material ratio and compression ratio, and the correlation of material moisture content and compression ratio. The optimized process parameters were verified by the field experiments. An optimal combination of process parameters was determined to be the application of 1.5‰ microbial bacteria dosage, maturity for 32 days, material moisture content of 60%, compression ratio of 39.50%, and the material ratio of 23%. In this case, the seed germination index of small-scale compost fertilizer reached 96.52%, where the detection of indicators can meet the national standards for organic fertilizer and the requirements of agricultural production, while, the local straw and livestock manure can be nearby used conveniently. The findings can provide a theoretical basis for the local compost of organic fertilizer in small scale, further to design the supporting equipment in low-carbon agriculture. [ABSTRACT FROM AUTHOR]

An abundant supply of stover in northern China remains after corn grain harvest. The collected stover resources are about 6.74×108 t in 2017. Converting stover bales into renewable energy for clean heating is attracting much attention to save many stover resources, further possibly to replace coal, and thereby positively contribute to air quality, rural communities, and society at large. According to the whole life cycle in sustainable agriculture, in this study, a systematic evaluation was carried out to use a 3E (Economic, Energy and Environment) model, ranging from crop planting and harvesting to stover burning for heating, in order to explore the energy efficiency, economic benefits, and greenhouse gas emissions of baled stover burning boiler for clean heating. The results showed that the heating from baled stover burning has better energy and economic benefits, with less emissions of greenhouse gas. The clean heating can be expected suitable for the heating in winter in villages and towns with concentrated living, and for the urban district heating, such as agricultural and industrial parks. The heating area ranged from 5 000 to 100 000 m², the net energy of baled stover for heating was 10 512-10 774.8 MJ/t, and the energy output-input ratio was 8.4-8.5, indicating that the energy conversion rate was relatively high. In addition, the greenhouse gas emissions (CO2 eq.) were 9.67-11.21 g/MJ. The total cost of heating by burning stover bales was 391.1 yuan/t (equivalent to 16.2 yuan/m²) -560.5 yuan/t (equivalent to 23.8 yuan/m²). Calculating at an 8% rate of return, the heating scale can be more than 20 000 m². If only considering operating costs without the depreciation, the heating area can be more than 10 000 m2. The baled stover burning for heating can achieve the best energy efficiency, while the least emissions of greenhouse gas, compared with stover densified biofuel, and stover carbon-gas co-generation. The net energy output of three stover heating can be less than that of coal heating, but the greenhouse gas emissions can be only from 1/10 to 1/7 of that of coal, indicating the environmental benefits are significant. Therefore, it is highly recommended to further improve the heating facilities in villages and towns of northern China, and thereby promote the application of clean heating, such as baled stover burning, densified biofuel, and pyrolysis carbon-gas cogeneration. Stover clean heating can be used to effectively alleviate air pollution and reduce emissions of greenhouse gas in a renewable energy source. [ABSTRACT FROM AUTHOR]

Modifications were made to a conventional ear-snapper corn header to increase corn stover yield when a single-pass round baling system was integrated with a combine harvester. To collect more leaves and top portions of stalks, knives oriented parallel to the deck plates were added to shear crop material above the ear-snapper rolls. Stover yield was primarily altered by the number of knives on the header; and to a lesser extent by the fore-and-aft position of the knives and the header height. The number of knives on a 12-row header was varied from two to six in increments of two. Stover yield increased linearly with the number of knives, and dry basis stover yield ranged from 1.1 Mg ha-1 (no knives) to 3.6 Mg ha-1 (six knives) over the five years of data collected (2012 to 2016). Combine productivity decreased linearly and specific fuel consumption increased linearly with greater stover yield. Combine productivity declined by as much as 50% when six knives were used. Dry basis bale density decreased linearly with the number of knives because the dense cobs became a smaller fraction of the total bale mass. In three of the five years, bale moisture increased linearly with the number of knives; in those three years, bale moisture was typically greater than 30% (wet basis). Adding knives to the header increased single-pass stover yield but at considerable cost to combine harvester productivity, and aerobic bale conservation would be challenged by high bale moisture. [ABSTRACT FROM AUTHOR]

Genotype, environment and their interactions are important determinant of crop phenotypes. In present study, oat genotypes including advanced lines (candidate varieties), approved cultivars, obsolete cultivars and germplasm accessions were evaluated at three sites under terminal phase heat stress to study the response of heat resistant elite advanced oat lines. Genotype + Genotype × Environment was used to select better genotype across three experimental sites. Advanced lines such as "Sgd-1", "Sgd-oat-2011" and "Fsd-oat" were selected for better yield under the terminal heat stress which had better green fodder yield (GFY) and also showed stable performance when compared at three locations. These advanced lines provided a yield advantage of 10% when compared with standard checks under heat stress. Among the yield components, plant height (PH) had positive association with GFY at all locations and this trait may be prioritized for the selection of high yielding genotypes. "S-2000" showed better performance for leaf area, "Sgd-oat-2011" and "CK-1" had been stable for tiller number and "Fsd-Oat" showed stable performance for stem thickness at all three locations. The results showed that candidate variety "Sgd-1" found to be superior cultivar for general cultivation due to its higher GFY, tiller number and PH. Moreover, Sgd-1 was heat tolerant cultivar and can be recommended for general cultivation subjected to terminal phase heat stress. [ABSTRACT FROM AUTHOR]

BACKGROUND Plant biomass rich in lignocelluloses may be applicable for the production of highly valuable bioproducts. In this study, the use of hydrolyzed corn stover as a carbon source for yeast producing 2‐phenylethanol (2‐PE) is investigated. 2‐PE is an alcohol with a rosy scent, commonly used in the food and cosmetic industries as an aroma and preservative. The growing demand for this compound motivates the development of new methods of production. RESULTS: The corn stover biomass was first pretreated with an alkaline solution of H2O2 and secondly hydrolysed with a cellulolytic enzyme cocktail to cause the saccharification of polycarbohydrates and the release of fermentable monosugars. This resulted in saccharification yields of up to 88.1 ± 7.6% and 92.5 ± 9.1% related to cellulose (glucan) and hemicellulose (arabinoxylan) content, respectively. Next, the obtained hydrolyzates were used as a feedstock for 2‐PE production by two nonconventional yeasts, Metschnikowia chrysoperlae WUT25 and Pichia fermentans WUT36. The highest 2‐PE titer of 3.67 g L−1 was attained with the WUT36 strain. Finally, 2‐PE was extracted from the fermentation broth with ethyl acetate (100% recovery) and purified by distillation to 97.27 ± 0.08%. CONCLUSION: This is the first report demonstrating the promising and complete route of 2‐PE production by yeast in a medium based on the hydrolyzate of corn stover. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Quantifying historical changes in maize harvest index (HI), the fraction of above-ground biomass allocated to grain yield, can enhance our ability to explain grain yield trends and estimate stover carbon inputs for sustainability assessments. However, the HI genetic gain has not been the primary focus of previous era studies. The aim of this study is to enhance our knowledge of maize HI genetic gain. Our first objective is to quantify HI genetic gain in Bayer Crop Science Legacy hybrids and investigate the contribution of breeding and agronomic management. Our second objective is to develop a general-use model to describe the temporal evolution of maize HI. We studied 54 commercial hybrids (103-day and 111-day relative maturities) released from 1983 to 2020 across 13 environments, including plant density (current and historical increasing rate) and N-fertilizer (low and sufficient N rates) treatments. The HI was estimated at physiological maturity by destructively sampling plants. Then we synthesize new experimental data with literature findings (n = 16) to provide a robust HI genetic gain estimate. Results showed that HI has increased over the years from 0.516 to 0.571 in 103-day hybrids and from 0.537 to 0.584 in 111-day hybrids. The genetic gains were similar across environments and management treatments within the studied range, indicating that this increase is attributed to maize breeding. The N-fertilizer treatments affected the magnitude of the HI, but plant density did not. Our results, combined with 16 literature datasets, revealed a 0.26% year−1 relative increase in HI since 1964. We estimated that the increase in HI accounts for ca. 15% of the historical maize yield increase in the US Corn Belt over the past 50 years. The maize HI has increased over the last 50 years, and this increase was attributed to breeding, not to management. Our findings enhance our knowledge of maize HI, will support robust estimations of carbon inputs in sustainability studies, and inform crop models to better capture historical yield increases. • We quantified harvest index (HI) genetic gain in maize hybrids. • The HI relative genetic gain was 0.26% year−1 since 1964. • The HI increase is attributed to breeding, not to management. • Plant density and N-fertilizer treatments did not affect the HI genetic gain. • We estimated that the increase in HI accounts for 15% of the historical maize yield increase in the US Corn Belt. [ABSTRACT FROM AUTHOR]

Biomass yields and concentrations of crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber (CF) were analyzed for five cultivars of summer-sown maize (Zea mays L.) stover grown in field trials at three rates of N fertilization, and sampled immediately after grain harvest. The results revealed differences in yields and concentrations of nutrients according to stalk height and hence harvest portion among the cultivars. N application greatly increased biomass yield and CP, especially in upper stalks and to a lesser extent, EE. Concentrations of NDF and ADF decreased as N rate increased. The results show that stovers from all local popular maize cultivars are suitable as animal fodder and that moderate N application improves feed quality of stover.

This study was conducted to identify the crop management options—the combinations of various cultivars, irrigation amounts, planting dates, and soils—that would maximize the energy sustainability and eco-friendliness of maize (Zea mays L.) stover-based ethanol production systems in the Mississippi Delta. Stover yields simulated with CERES-Maize were used to compute net energy value (NEV) and carbon credit balance (CCB), the indicators of sustainability and eco-friendliness of ethanol production, respectively, for various scenarios. As the results showed, deeper soils with higher water holding capacities had larger NEV and CCB values. Both NEV and CCB had sigmoid relationships with irrigation amount and planting date and could be maximized by planting the crop during the optimum planting window. Stover yield had positive effects on NEV and CCB, whereas travel distance had negative. The influence of stover yield was larger than that of travel distance, indicating that increasing feedstock yields should be emphasized over reducing travel distance. The NEV and CCB values indicated that stover-based ethanol production in the Mississippi Delta is sustainable and environmentally friendly. The study demonstrated that the energy sustainability and eco-friendliness of maize stover-based ethanol production could be increased with alternative crop management options.

Yellow silage corn stover is taken as a kind of important feedstuff for animal husbandry. Corn stover pickup balers are used to collect the stover and bundle it into straw bale in the harvest process of yellow silage corn stover. But in Northeast China, the soil has strong adhesiveness when it is in high moisture content. And when the moisture content is low, the soil disperses into fine particles which are easily carried in the miscellaneous branches of stover. It is a fleeting moment when stover is gathered and transported into baler. Soil adhered to stover and carried by the branches can’t be removed in this short process. As a result, high soil content reduces feed quality of yellow silage corn stover. In order to solve the problem of high soil content of yellow silage corn stover, the paper proposed to remove the soil adhered and included in stover by means of vibration. The soil removal mechanism of stover pickup baler by vibration was fitted on the bottom of the machine. It is connected between the pickup unit and the cutting and rubbing unit. Stover can be picked up and delivered to the vibrating conveying screen to remove the soil. Then, the stover would be robbed, cut and bundled. The operating principle of the test-bed was clarified through the design of the test-bed and analysis of high-speed camera. Collision between stover and screen and internal friction of stover could release soil in the stover. Stover thickness, vibration time, vibration amplitude and vibration frequency were 4 influencing factors acting on performance of soil removal in the tests. Taking the soil removal rate and the stover loss rate as indices, single factor experiments were conducted to determine the value range of each parameter on the whole-plant stover (long stover) and chopped stover (short stover) on the ground respectively. The result showed that the soil removal rate and the stover loss rate increased with the increase of vibration time, vibration amplitude, and vibration frequency. But the soil removal rate and the stover loss rate dropped with the increase of stover thickness. It was given that the focus ranges of values of all parameters were vibration time from 10 to 14 s, vibration amplitude from 10 to 20 mm, vibration frequency from 4 to 6 Hz for long stover, and vibration time from 12 to 16 s, vibration amplitude from 10 to 20 mm, vibration frequency from 4 to 6 Hz for short stover. Through the three-factor orthogonal polynomial regression test, the author found the change laws of the soil removal rate and the stover loss rate determined by vibration frequency, vibration amplitude and vibration time. Four regression equations were induced according to experiment and analysis above. Then, a comprehensive index indicating soil removal rate and stover loss rate toward the optimum synchronously was made to evaluate the effect of soil removal. By analyzing the regression equations and the comprehensive index, an optimal solution was obtained. The optimal combination of soil removal from corn stover by vibration was as follows: For the long stover, the vibration amplitude was 15 mm, the vibration frequency was 4.5 Hz, and the vibration time was 14 s; for the short stover, the vibration amplitude was 20 mm, the vibration frequency was 4 Hz, and the vibration time was 12 s. Verification tests were conducted on the test-bed to verify the results above. Through calculating with the regression equations, the soil removal rate and the stover loss rate of long stover were 4.71% and 0.34%, respectively, and for short stover, the calculating results were 4.44% and 1.42% respectively. In the verification tests, the results were 4.80% and 0.38% for long stover and 4.72% and 1.53% for short stover. By comparing the simulated and the experimental result, it was found that the relative errors of the soil removal rate and the stover loss rate were acceptable. It was believed that the result of mathematical model matched the test result well. This study provides references not only for removing soil from stover by vibration, but also for the improvement of corn stover pickup baler design. [ABSTRACT FROM AUTHOR]