Crop Straw Research Articles

Improving long‐term crop productivity and soil quality through integrated straw‐return and tillage strategies

AbstractLong‐termagricultural sustainability receives increasing concerns owing to the inappropriate removals of crop straw with frequent tillage, causing soil degradation and reduced productivity. A 7‐yr field experiment was conducted to exploit the optimal integrated straw‐return and tillage strategy for maintaining soil quality and sustaining crop productivity in an intensive wheat (Triticum aestivum L.)–maize (Zea mays L.) cropping system in the Guanzhong Plain. Three strategies were tested for wheat: straw harvest (Wh), straw return with chopped straw distribution on soil surface (Wr) and with stubble 30–40 cm height (Ws); three strategies were for maize: straw harvest with rotary tillage (Mh), straw return with rotary tillage (Mr) and with subsoiling (Ms). Thus, nine integrated strategies were conducted per rotation period: WhMh, WhMr, WhMs, WrMh, WrMr, WrMs, WsMh, WsMr, and WsMs. The results indicated that the eight integrated strategies (except WhMh) promoted both wheat and maize grain yields, and showed the largest increase for the system productivity (+42.3%) and sustainable yield index (+43.0%) under WsMs relative to the WhMh. In addition, significant increases were observed in various soil quality indicators under integrated strategies, especially under WsMs. The system productivity responses were predominately determined by mean weight diameter, soil organic carbon, available nitrogen, and available phosphorus. Therefore, the integrated strategies of wheat straw return with stubble 30–40 cm height and maize straw return with subsoiling can be advised for maintaining soil quality and improving crop productivity in the wheat–maize cropping system in the long term.

Molecular Insights into Roles of Dissolved Organic Matter in Cr(III) Immobilization by Coprecipitation with Fe(III) Probed by STXM-Ptychography and XANES Spectroscopy.

The coprecipitation of heavy metals (HMs) with Fe(III) in the presence of dissolved organic matter (DOM) is a crucial process to control the mobility of HMs in the environment, but its underlying immobilization mechanisms are unclear. In this study, Cr(III) immobilization by coprecipitation with Fe(III) in the presence of straw-derived DOMs under different Fe/C molar ratios, pHs, and ionic strengths was investigated using scanning transmission X-ray microscopy (STXM) and ptychography and X-ray absorption near-edge structure (XANES) spectroscopy. The results showed that Cr(III) retention was enhanced in the presence of DOM, a maximum of which was achieved at an Fe/C molar ratio of 0.5. The increase of pH and ionic strength could also promote Cr(III) immobilization. Cr K-edge XANES results indicated that Fe (oxy)hydroxide fractions, instead of organics, provided the predominant binding sites for Cr(III), which was directly confirmed by high spatial resolution STXM-ptychography analysis at the sub-micron- and nanoscales. Moreover, organics could indirectly facilitate Cr immobilization by improving the aggregation and deposition of coprecipitate particles through DOM bridging or electrostatic interactions. Additionally, C K-edge XANES analysis further indicated that the carboxylic groups of DOM were complexed with Fe (oxy)hydroxides, which probably contributed to DOM bridging. This study provides a new insight into Cr(III) immobilization mechanisms in its coprecipitation with Fe(III) and DOM, which could have important implications on the management of Cr(III)-enriched soils, particularly with crop straw returning.

Instant catapult steam explosion pretreatment of wheat straw liquefied polyols to prolong the slow-release longevity of bio-based polyurethane-coated fertilizers

The direct liquefaction product of crop straws for bio-based polyurethane-coated fertilizers (BPCFs) has low hydroxyl values and complicated composition types, resulting in poor crosslinking degree, high hydrophilicity, and short release longevity. This study created an efficient physicochemical instant catapult steam explosion pretreatment wheat straw (SEWS) technology to remove small molecular hemicellulose and difficult-to-film-forming ions, improve straw liquefied polyol quality, and extend the release longevity of BPCFs. The results revealed that the steam explosion process (2.0 MPa for 5 min) broken the straw cell wall, hydrolyzed hemicellulose, and significantly decreased the difficult-to-film-forming ions (K+, Ca2+, and Mg2+). The SEWS liquefied residue rate dropped 38.1% to 5.5%, while the hydroxyl value increased 36.51% to 125.32 mg KOH g−1. The liquid polyol of SEWS and diphenyl-methane-diisocyanate formed a tightly cross-linked, homogenous bio-based membrane with no visible holes. Under the condition of 3% weight of the core fertilizer, the release longevity of SEWS increased from 14 to 32 days. The use of instant catapult steam explosion technology for high-efficiency pretreatment of biomass materials is conducive to improving the quality of bio-based polyols and the industrial production of bio-based controlled-release fertilizers. Furthermore, the pretreatment technology promotes the use of biomass for sustainable agriculture.

Energy Potential and Sustainability of Straw Resources in Three Regions of Ghana

Anthropogenic global warming and the depletion of nonrenewable resources necessitate a transition towards bioenergy to accelerate sustainable development and carbon neutrality. This study quantified the availability and energy potential of crop (cereals, legumes, roots and tubers) straws based on data from the Northern, North East and Savannah regions in Ghana. The annual technical straw potential was 2,967,933 tonnes, whilst the crop straws with the highest technical potential were yam (935,927 tonnes), groundnut (485,236 tonnes), maize (438,926 tonnes) and soybean (374,564 tonnes). The technical energy potential of all the crop straws was 42,256 TJ, although the energy potential of yam, groundnut, maize and soybean was 13,922 TJ, 7611 TJ, 5704 TJ and 5409 TJ, respectively. There was a linear correlation between the straw produced and the energy potential per region. The Northern region (28,153 TJ) recorded the highest energy potential followed by the Savannah (8330 TJ) and North East (5773 TJ) regions. To serve as context, the research placed an emphasis on the sustainability of crop straws for bioenergy and added a brief analysis of the life cycle assessment (LCA) of bioenergy scenarios to explore the environmental sustainability of crop straw-based power generation. This study will serve as a reference in understanding LCA inference on practicable research of crop straw-based, power plant expansion in Ghana and Sub-Saharan Africa (SSA).

The Influence of Ecologised Fertiliser Systems on the Elements of Fertility and Productivity of Winter Wheat

One of the strategic areas for the development of modern agriculture is the use of ecologised fertiliser systems composed based on the straw of agricultural crops with the addition of microbiological, humus or chelated fertilisers. This will allow restoring natural resources and getting environmentally friendly products. The purpose of the research was to study the effect of ecologised fertiliser systems on the physical and chemical processes and nitrogen regime of grey forest soil, the development of bio-productivity of winter wheat, and the content of basic microelements in grain. The following methods were used in the research: field, laboratory-analytical, mathematical-statistical. Application of N30P45K45 against the background of pea straw with the addition of a biostimulator and humus fertiliser mostly demonstrated modern approaches to technologies for managing the fertility of grey forest soils based on the principles of environmental safety and resource conservation. Such a fertiliser system provided alkalinisation of the soil solution, optimisation of the Ca2+ and Mg2+ content, improvement of the soil nitrogen regime. Under such conditions, optimal parameters of the production process elements (the number and mass of grains in the head) were formed. The most effective in the processes of accumulation of microelements was the organo-mineral system of the following composition: pea straw + N30R45K45 + chelated fertiliser. No excess of the maximum permissible concentration for Cu, Zn, Mn, or Fe was detected. Thus, to harmonise the ecological and productive functions of grey forest soil in the winter wheat cultivation system, a combination of alternative agriculture, which consists in reducing the use of mineral fertilisers, and partial biologisation, is considered promising. This is a way to optimise soil fertility and bio-productivity

Seven years of biochar amendment has a negligible effect on soil available P and a progressive effect on organic C in paddy soils

Little attention has been paid to how long-term application of crop straw and its biochar affects soil phosphorus (P) transformation and carbon (C) fractions. We conducted a 7-year field experiment including control treatment (chemical fertilizer only, CK), straw return (2.25 t ha−1), and different amounts of biochar addition (11.25 t ha−1 (0.5%BC) and 22.5 t ha−1 (1.0%BC), to investigate influence of these amendments on soil C structure, P fractions, and their interaction with microorganisms. The 13C nuclear magnetic resonance and soil P sequence fractionation were applied to capture changes of soil C compositions and P pool. Compared to CK, straw and biochar amendments decreased alkyl C/O-alkyl C, which is conducive to increased soil organic C. The 0.5%BC and 1.0%BC treatments enhanced recalcitrant aromatic C by 69.0% and 131%, respectively. Compared to CK (101.2 ± 33.32 mg kg−1), the 0.5%BC and 1.0%BC treatments had a negligible effect on soil available P, while negative effects were observed in straw treatment (59.79 ± 9.023 mg kg−1). Straw and biochar amendments increased primary P and occluded P, whereas had negligible effect on organic P. Redundancy analysis and correlation analysis indicated that C compositions and P pool correlated to microbial community composition and enzyme activities, and aromatic C was the most related factor. Moreover, structural equation modeling indicated available P was most related to phosphatase activity and C composition. Our findings reveal the changes of soil P and C response under long-term crop straw and its biochar amendment, and can contribute toward improving understanding of the effect of biochar and straw return in future agriculture management.

Element partitioning, emissions, and relative risk during disposal processes of diverse litters, fruit tree branches, and crop straws: dry distillation, incomplete combustion, and sufficient combustion

Element partitioning, emissions, and relative risk during disposal processes of diverse litters, fruit tree branches, and crop straws: dry distillation, incomplete combustion, and sufficient combustion

Estimation of maize straw production and appropriate straw return rate in China

Accurate estimation of maize (Zea mays L.) straw production and exploration of appropriate straw return rate have important reference for guiding the comprehensive utilization of crop straw. In this study, we estimated the maize straw production (including aboveground straw and root straw) in recent ten years (2009–2018) of the four largest maize growing regions across China using the latest obtained region-specific maize straw index and root-shoot ratio and then determined the appropriate straw return rate of different regions based on the carbon (C) balance between straw C input and the total C emissions generated in maize cultivation. Our results showed that there were significant differences in maize straw index (MSI) and root-shoot ratio between different maize growing regions in China with spatial distribution trends of Huanghuaihai (HM) > North (NM) > Southwest (SW) > Northwest (NW) maize regions and SW > NW > NM > HM, respectively. On average, in the recent ten years, the total maize straw production of the four major regions was 216.03 Mt yr−1, including 192.73 Mt yr−1 for the aboveground straw production and 23.30 Mt yr−1 for root straw production. Nationally, when the maize straw return rate was 70.4% (45.8%, 57.4%, 62.2% and 84.5% in SW, HM, NW and NM respectively), the straw C input into soil can theoretically counterbalance the total C emission generated in maize cultivation. Additionally, the total soil organic C sequestration increased from 11.26 to 18.88 Mt C yr−1 for the whole four regions under the scenarios of 0%, 25%, 50%, 75% and 100% maize straw return.

Effects of straw mulching on predatory myxobacterial communities in different soil aggregates under wheat-corn rotation.

Crop straw mulching is an important organic supplement in sustainable agriculture; however, the effect of increased organic matter on the diversity of micropredators such as myxobacteria and the correlation between myxobacteria and microorganisms have been little explored. In the current investigation, high-throughput sequencing was performed to analyze the myxobacterial community composition in a wheat-corn rotation experimental field with 6-year straw mulching and fertilization treatments. The results reveal no significant influence of straw mulch application on myxobacterial α-diversity (P < 0.05). NMDS (nonmetric multidimensional scaling) and perMANOVA results indicate the significant influence of straw mulching application on myxobacterial community composition (P < 0.05), and several groups, including Haliangiaceae, Polyangiaceae, and Archangiaceae, also varied in soil aggregates. RDA (redundancy analysis) results show that TOC (total organic carbon) was the most important factor affecting the myxobacterial community structure. In addition, RDA and random forest analysis results show the contribution of myxobacterial community structure to soil bacterial community α- and β-diversity, especially in the 0.25-1mm and < 0.25mm soil aggregate fractions. In conclusion, we suggest that the variation in myxobacterial community structure may be a driver of bacterial α- and β-diversity in soil microhabitats and might be a cause of soil microbial community changes. Our results are fruitful for finding more efficient ways to use straw from waste for the betterment of sustainable agriculture by analyzing changes in myxobacterial community structure.

Rice straw carbon mineralization is affected by the timing of exogenous glucose addition in flooded paddy soil

Crop straw amendment is a farm management approach for enhancing soil carbon sequestration. Moreover, crop straw residue decomposition rates are affected by irregular exogenous organic carbon secretion or metabolism such as that from root exudates or microbial metabolites. To quantify the mineralization rate of straw residue affected by exogenous organic carbon addition and elucidate the underlying mechanisms, in this study, a total of 0.5 g 13C- labeled dry rice straw was added into pre-incubated soil (equivalent to 200 g dry soil) and incubated for 20 days. Then,1mL of a solution with 50 mg glucose was added only once into the soil on day 21 (G(1a)) or day 35 (G(1b)), twice with 25 mg glucose every 14 days (G(2)) or four times with 12.5 mg glucose every 7 days (G(4)). Soil without glucose addition served as a control. The frequent addition of glucose induced higher soil respiration than that induced by only one addition, and stimulated the mineralization of rice straw carbon compared to that in the control in the following order: G(4) (14.6%) > G(1a) (12.7%) > G(2) (12.3%) > G(1b) (11.2%) = control (11.2%). In general, frequent addition of glucose decreased the soil redox potential (Eh) and fungi to bacteria ratio. Structural equation modeling analysis showed that the rice straw carbon mineralization rate was positively correlated with the 13C-dissolved organic carbon (13C-DOC) content and negatively regulated by Eh. Microbial bioactivity exerted indirect positive effects on rice straw carbon mineralization by influencing the 13C-DOC content. A decrease in the fungi to bacteria ratio induced by frequent addition of glucose improved the microbial bioactivity and enhanced rice straw carbon mineralization. Our results suggested that single exogenous organic carbon additions may underestimate residue or soil organic matter decomposition rates in the field.

Operation management of hybrid biomass power plant considering environmental constraints

Crop straw can not only be used as a raw material for bioenergy, but also can protect the soil after returning to the field. This research constructs a hybrid operation management model for combined power generation with multiple biomass fuels, with the purpose of exploring the impact of environmental protection on the operation and maintenance of biomass companies. First, the potential straw supply under different soil function protection scenarios was calculated. Based on this, a biomass power plant operation strategy was formulated under the mixed supply of multiple biomass. Lastly, taking Shandong Province as a sample case to verify the effectiveness of the model, we found that, (1) the theoretical amount of straw in Shandong Province in 2019 is about 78.57 million tons. Taking into account the agricultural, industrial and household use of crop straw, the total available straw in Shandong Province is 10.3–22.31 million tons. (2) owing to the heterogeneity of different straws, soil function protection will have great impacts on the inventory management of straw power plants. Reasonable straw allocation under different soil function protection scenarios can greatly improve the efficiency of different crop straws. In the case of high return to the field, the selection of maize decreased by 20%, and the amount of straw represented by potato increased by 40%. (3) Prioritizing soil function protection will reduce the total amount of straw that can be used for bio-energy production and reduce carbon dioxide emissions in the process of power generation. Therefore, when planning arbon capture and storage (CCS) technology based on straw power generation, the impact of soil function protection should also be fully considered.

Design of Crushing Mechanism of Mobile Straw Granulator

Background: Crop straw is a valuable renewable biological resource. In this study, a mobile straw granulator was designed to fully and efficiently use crop straw. The key crushing mechanism device of the mobile straw granulator was also designed in detail. Methods: The first three natural frequencies and vibration modes of the crushing roller are obtained by applying ANSYSWorkbench software to the modal analysis of the crushing roller. Results: The lowest natural frequency of the crushing roller was 165.83 Hz, which was higher than its working frequency of 30 Hz and would not cause resonance. Three factors and three levels were tested using the average resistance of the blade as an index and the blade edge angle, the blade thickness, and the blade end width as the test factors. Conclusion: The optimal parameter combination obtained by software analysis is blade edge angle of 30°, blade thickness of 8 mm, and blade width of 75 mm. With this parameter combination, the blade power consumption is the smallest, the service life is the largest, and the crushing effect is the best.

Substituting nitrogen and phosphorus fertilizer with optimal amount of crop straw improves rice grain yield, nutrient use efficiency and soil carbon sequestration

Crop straw return after harvest is considered an important way to achieve both agronomic and environmental benefits. However, the appropriate amount of straw to substitute for fertilizer remains unclear. A field experiment was performed from 2016 to 2018 to explore the effect of different amounts of straw to substitute for fertilizer on soil properties, soil organic carbon (SOC) storage, grain yield, yield components, nitrogen (N) use efficiency, phosphorus (P) use efficiency, N surplus, and P surplus after rice harvesting. Relative to mineral fertilization alone, straw substitution at 5 t ha−1 improved the number of spikelets per panicle, effective panicle, seed setting rate, 1000-grain weight, and grain yield, and also increased the aboveground N and P uptake in rice. Straw substitution exceeding 2.5 t ha−1 increased the soil available N, P, and K concentrations as compared with mineral fertilization, and different amounts of straw substitution improved SOC storage compared with mineral fertilization. Furthermore, straw substitution at 5 t ha−1 decreased the N surplus and P surplus by up to 68.3 and 28.9%, respectively, compared to mineral fertilization. Rice aboveground N and P uptake and soil properties together contributed 19.3% to the variation in rice grain yield and yield components. Straw substitution at 5 t ha−1, an optimal fertilization regime, improved soil properties, SOC storage, grain yield, yield components, N use efficiency (NUE), and P use efficiency (PUE) while simultaneously decreasing the risk of environmental contamination.

Analysis and Prospect of Key Technologies for Crop Straw Recycling

For the whole process of straw recycling and processing of various general crop harvesters, summarize and analyze the current key technology research in the fields of crop straw recycling and processing technology, foreign matter detection and positioning technology, crop cleaning technology, robot technology, etc., aiming at the efficient recovery of crop straw, the efficient and accurate detection and positioning methods of foreign matters such as stones, soil blocks and metals, the rapid removal of foreign matters. Prospects are made in several key technologies, corresponding technical innovation suggestions are put forward for designers in related fields. It will help to obtain the straw recovery and precise foreign matter detection system that is universal for general agricultural machinery and help the development of efficient and precise agriculture all over the world.

УРОЖАЙНОСТЬ И ФИТОСАНИТАРНОЕ СОСТОЯНИЕ ПОСЛЕДНИХ КУЛЬТУР СЕВООБОРОТА ЯРОВОЙ ПШЕНИЦЫ И ЯЧМЕНЯ

The article shows the analysis of the effect of long-term application (since 2006) of nonmoldboard and combined systems of main tillage in a crop rotation in comparison with annual moldboard tillage on productivity of spring wheat, yield and phytosanitary state of barley. The author studied tillage options in a cereal-grass rotation (71% cereals) with different types of fallow (clean, manured, clover and mustard) and with winter rye straw left in the field. Annual mouldboard tillage resulted in the highest yields of spring wheat and barley in the experiment – 2.90 and 2.31 t/ha. Annual nonmoldboard tillage resulted in a significant reduction in wheat yield to 2.61 t/ha and barley yield to 1.28 t/ha. The combined tillage system, alternating two mouldboard and four nonmoldboard treatments per rotation, ensured the wheat yield at the level of the mouldboard system – 2.82 t/ha, and a decrease in barley yields to 1.85 t/ha. In 2020, the limiting factor for barley yield formation in the variants with surface distribution of crop residues and straw was increased weed infestation and deterioration of the phytosanitary state of the crop. Straw had a depressive effect on the yield of the last crops in a crop rotation with pure fallow. Crop yields decreased by 0.43 and 0.26 t/ha. Wheat yield was 2.34 t/ha, barley yield was 1.41 t/ha. Green manure mustard and clover fallows leveled the depressive effect of straw. The yields of the 6th and 7th crops of the crop rotation were at the control level (2.69–2.78 t/ha of wheat and 1.70–1.81 t/ha of barley). Regardless of the tillage system and the use of by-products as organic fertilizer, the application of manure ensured the highest yields of the final crops of the rotation: 3.10 and 2.99 t/ha for spring wheat and 2.00 and 2.14 t/ha for barley.

Improving the Staged Gasification of Crop Straw by Choosing a Suitable Devolatilization Temperature

Improving the Staged Gasification of Crop Straw by Choosing a Suitable Devolatilization Temperature

Atividade alimentar da fauna do solo em sistemas de produção sob palhadas de plantas de cobertura

ABSTRACT To preserve a desirable level of soil quality, especially taking into consideration its health and sustainability, is not an easy task, due to the numerous factors that influence it. This study aimed to measure the feeding activity of soil fauna in production systems under cover crop straws sampled at the depth of 0-8.0 cm. A randomized blocks design, with four replicates and eight treatments, was used, corresponding to soybean cultivation under the following cover crop straws: maize monoculture; maize intercropped with Urochloa ruziziensis; U. ruziziensis monoculture; sorghum intercropped with U. ruziziensis; sorghum monoculture; sunflower intercropped with U. ruziziensis; mix (millet + Crotalaria spectabilis + U. ruziziensis); and a fallow treatment. At the depth of 1.0 cm, there was a variation of 63.59-37.06 % for consumption among the treatments, with the highest consumption for the mix, if compared to the fallow treatment. At the depth of 2.0-7.0 cm, the consumption did not vary among the treatments. For the depth of 8.0 cm, the fallow treatment presented the highest consumption (45.76 %; p &lt; 0.05), when compared to sunflower intercropped with U. ruziziensis (20.51 %), sorghum (20.58 %) and sorghum intercropped with U. ruziziensis (18.96 %).

Decomposition of Maize Straw between Two Phosphate Solubilizing Fungi: Aspergillus Niger and Penicillium Chrysogenum

Aspergillus niger (A. niger) and Penicillium chrysogenum (P. chrysogenum) can significantly promote the degradation of maize straw and phosphorus release. Compared with P. chrysogenum, A. niger is more efficient in maize straw degradation and phosphorus releasing. After seven days of incubation, the highest degradation ratio and phosphorus content in A. niger+maize straw treatment is 2.58% and 2.3 mg/L, respectively. The mechanisms for maize straw decomposition between these two fungi are different. Oxalic acid is the primary organic acid secreted by A. niger, which is more function in the decomposition of maize straw compared with propionic acid secreted by P. chrysogenum. In addition, A. niger has higher acidic xylanase and lignin peroxidase enzymes activities, which is conducive to the degradation of more stable substances in maize straw, i.e., lignin. This study indicated that A. niger is the primary candidate for the reuse of crop straw in the way of return to the field.

Plough Tillage Maintains High Rice Yield and Lower Greenhouse Gas Emissions Under Crop Straw Incorporation

Plough Tillage Maintains High Rice Yield and Lower Greenhouse Gas Emissions Under Crop Straw Incorporation

Analysis of Agricultural Biomass Energy Use and Greenhouse Gas Reduction Evidence from China.

China is a large agricultural country, where agricultural activities and rural life cause a large amount of greenhouse gas (GHG) emissions. In the process of crop growth, production, and processing, a large number of crop straws and agricultural wasted products are produced, which become one of the important sources of biomass resources. However, few detailed studies focused on the potential of China's agricultural biomass energy conversion and carbon emission reduction, and fewer studies proposed GHG emission reduction strategies from the perspective of making full use of China's agricultural waste resources. In this study, the quantity calculation index of agricultural biomass energy was given, and the GHG emission reduction potential calculation index of agricultural biomass energy was constructed, with which the amount of GHG emissions caused by agricultural waste use in China was measured and the potential of GHG emission reduction caused by agricultural waste use would be easily speculated. Based on the statistical data of China, the quantity and GHG emission reduction potential of agricultural biomass resources in China in the recent 10 years (2009∼2018) were clarified. According to the research, the amount of agricultural waste equivalent to standard coal in China from 2009 to 2018 reached 280,0711 million tons. If all these resources were used to replace coal, a total of 4,474,483 million tons of carbon dioxide emissions could be saved. Assuming that these wastes are anaerobic, carbonized, or fully burned as fuel, CH4 emissions could be reduced by up to 12.024 million tons and N2O emissions by up to 185,000 tons. It can be seen that the effective utilization of agricultural biomass resources can replace coal, reduce backwardness such as land burning, and then reduce CO2, CH4, N2O, and other greenhouse gas emissions, and promote the realization of carbon peak and carbon neutrality.