Grass Biomass Research Articles

The effect of mineral fertilisers and herbicides on the seed productivity of perennial grasses in Yenisei Siberia

On the dark grey forest soils of the taiga zone of the Yenisei Siberia, the structure of the weed component of agrophytocenoses of perennial grasses is dominated by perennial segetal and segetal-ruderal weed species, the proportion of which is 60-70%. Using Magnum herbicides in timothy grass Kazachinskaya 2 and Lontrel-300 in the crops of meadow fescue grass Kazachinskaya 182 allowed for reducing the contamination of fields with perennial weeds from medium to weak. Herbicides reduce 94% the weight of weeds from 1 ha while increasing the biomass of timothy grass by 30%. Against the background of fertilizers, the weight of weeds decreased by 85.3%, and the importance of timothy grass increased by 118%. Mineral fertilizers increase the yield of timothy seeds for three years of use from 3.64 c / ha to 5.31-8.62 c / ha and oatmeal seeds - from 3.22 c/ ha to 4.97-6.91 c /ha. The complete collection of grass seeds was obtained on variants N60P60K60 with the leading share of the influence of nitrogen fertilizers, the introduction of which increased the yield of timothy seeds by 125% and fescue by 87%. The introduction of potash fertilizers caused an increase in the output of timothy grass of the 2 and 3 g. p. by 160 and 190%, respectively, and fescue of the 2 g. p. by 160%. The sowing qualities of seeds characterized by germination energy, germination and weight of 1000 seeds of timothy increased under the influence of phosphorus and potash fertilizers.

Crop and livestock productivity, soil health improvement and insect dynamics: Impact of different fodder-based cropping systems in a rainfed region of India

CONTEXTFarmers in rainfed areas of South Asia depend on livestock to augment income, and provide manure for soil and crops. However, the full potential of the livestock is not realized due to the non-availability of quality fodder. The deficit may be attributed to limitation in expansion of cultivable land as well as non-availability of fodder from the protected forest areas. It is possible to enhance the productivity of the livestock by crop-livestock systems. OBJECTIVESThis study was conducted to determine the crop and fodder production potential, nutritive value of the fodder, and reductions in soil nutrients loss and pests of the seven fodder-based inter-cropping systems in a rainfed region in South India. METHODSA medium-term field experiment was conducted from 2015 to 2021 at the Gungal Research Farm of ICAR's Central Research Institute for Dryland Agriculture (17o05’ N, 78o39’E) with seven fodder-based cropping systems involving conventional crops either alone or in combinations with annual or perennial fodder species. The seven systems (treatments) were: sorghum + pigeon pea - hedge lucerne, sorghum + pigeonpea - guinea grass, castor - hedge lucerne, castor - guinea grass, sorghum - fodder - clusterbean - fodder-cowpea - fodder -horsegram, sole sorghum, and sole pigeonpea. Impacts of these systems on crop and livestock productivity, reductions in surface soil erosion and nutrient loss, and soil health and pest dynamics were studied. Livestock based studies were also conducted with the harvested fodders. RESULTS AND CONCLUSIONSWe found that sorghum + pigeonpea-hedge lucerne on average can produce 3865 kg ha−1 of sorghum grain equivalent yield and 37,820 kg ha−1 of sorghum fodder equivalent yield. The sorghum + pigeon pea-guinea grass would benefit the farmers with no animals, by selling the high biomass grass fodder and minimizing the risk of crop failure. These two systems are also better in providing green fodder for at least 8–9 months without any supplementary irrigation. We also observed increase in soil N, OC and soil microbes. There was reduction in runoff (by 51–52%) and sediment loss (by 52%), and reduced pest and disease incidence in these systems. SIGNIFICANCEOur study demonstrated that perennial fodder-based cropping systems are an excellent option to enhance the sustainability and livelihood security of rainfed farmers by reducing the risk of crop failure and supporting the livestock. These systems also open up the scope of integrating tree fodders especially in the bunds and farm borders.

Forest restoration in old pasture areas dominated by <i>Urochloa brizantha</i>

In the present study it was evaluated the density of recruits in an area previously occupied by Urochloa brizantha pasture undergoing forest restoration and in a Semideciduous Forest. Was evaluated the effect of the available light on the biomass of the exotic grass, and investigated associations of recruit density with soil variables and understory light availability. The seed rain in both areas was also evaluated. The biomass of U. brizantha was positively associated with available light and, a negative association was found between recruit density and available light when considering the two areas together. A negative associatio between recruit density and soil pH was found. The results suggest that the low soil fertility did not limited recruitment in the semideciduos forest. The results showed that high resource availability favors the competitivity of U. brizantha, impairing the forest restoration in area previously used as pastures. So, pratices that result in decreasing in light availability would favors the forest restoration in areas previously used as pasture.

The Effect of Continuous Grazing and Rest Rotational Management Systems on Grass Species Composition, Basal Cover and Production on Three Soil Types in the North West Province, South Africa

Rangelands represent the most extensive land cover type on Earth and many people depend on these rangelands for their livelihoods and for the ecosystem services that effect human wellbeing. The impact of grazing on community structure and ecosystem functioning is a key issue for rangeland management in order to maximize livestock production and sustainability of the operations. It is a known fact that soil differences cause differences in the palatability and utilization of grasses. Year-round continuous grazing is the management strategy used in the communal areas of the North West Province of South Africa. In this study the effect of continuous grazing and rest rotation grazing on grass species composition, basal cover and biomass production on different soil types were assessed. From the results it was clear that the effect of continuous grazing was the biggest on the andesitic soils (high clay), then the diabase soils (medium clay), whilst the effect on the quartzite soils was limited to even positive. In the rest rotation system, the effect of soil type on the different variables was negligibly small and the rangeland remained healthy and productive.

Patterns and predictors of ungulate space use across an isolated Miombo woodland reserve

AbstractUnderstanding ecological‐ and management‐related predictors of mammal space use within protected areas is critical for management planning. This is particularly true in small, fenced and isolated reserves where we hypothesised that management‐related activities will influence large herbivore space use more than ecological characteristics. We used camera trap data to assess the space use patterns for 18 ungulate species in the small and isolated Majete Wildlife Reserve (Majete) in the understudied Miombo woodland ecoregion of southern Malawi. In the 2018 dry season, the 691 km2 reserve was systematically surveyed for ungulate presence at 140 camera trap locations. Over a period of 5456 camera days, the survey yielded 11 078 independent detections of 18 ungulate species and three predators. Using a single‐species occupancy modelling framework, the probability of space use of ungulates was assessed in relation to five management (fire exposure, fire frequency, water availability, distance from fence and road) and five ecological (visibility, grass biomass, vegetation type, terrain ruggedness and predator abundance) space use covariates, while accounting for imperfect detection. Top‐ranked models contained multiple covariates for 15 of the 16 species modelled, with only nyala's (Tragelaphus angasii) space use best predicted by vegetation type only. Distance to water, vegetation type, visibility and fire frequency were predictors having strong influences on six or more species each. More management‐related covariates reflected in top models, but ecological covariates had more meaningful effect sizes making us reject the hypothesis. Importantly though, distance from the roads and fence were also identified as prominent predictors. Notably, black rhinoceros' (Diceros bicornis) probability of space use increased with distance from the reserve boundary. Beyond informing habitat management for ungulates in Majete, these results can form the basis for understanding species‐specific space use patterns in other small reserves with similar characteristics and threats.

Overcompensation of ecosystem productivity following sustained extreme drought in a semiarid grassland.

Drought events are projected to be more extreme and frequent in the future and have profound influences on the structure and functions of terrestrial ecosystems. Thus, better understanding the mechanisms of recovery is critical for predicting the future dynamics of terrestrial ecosystems. We performed a 7-year field precipitation experiment to examine recovery of a grassland ecosystem from different magnitudes of sustained drought, from slight to extreme. The ecosystem was exposed to precipitation treatments in the first 3 years (2010-2012) and recovered during the last 4 years (2013-2016) without precipitation treatments. Overall, large reductions of aboveground net primary productivity (ANPP, -43.3%) and perennial forb biomass (-83.1%) were observed in the third year (2012) of extreme drought only. Nevertheless, ANPP fully recovered within 1 year after the drought treatments were terminated, and the rapid recovery was mainly due to increased soil total nitrogen and root biomass allocation after drought. Surprisingly, large increases of ANPP under the extreme drought treatment occurred during the recovery periods from 2013 to 2015 (+74.1, +88.5, and +119.8 g m-2 year-1 ) compared to the control. The overcompensation offset the extreme drought-induced reduction of ANPP in the treatment years and was primarily ascribed to the enhanced biomass of perennial grasses (PG). Higher resistance to drought and fast resource acquisition strategy might drive the rapid recovery and expansion of PG. Our findings revealed the rapid recovery of grasslands and the critical role of community overcompensation in maintaining grassland ecosystem function and stability under future climate change scenarios.

Broadening the product portfolio with cellulose and lignin nanoparticles in an elephant grass biorefinery

AbstractCellulose and lignin nanoparticles are high‐value‐added products obtained from lignocellulosic biomasses through several steps of cellulose purification and lignin extraction. These steps drastically reduce the potential feedstock revenue when carried out as stand‐alone methodologies. To increase biomass yields, we describe here a strategy to design a biorefinery focused on producing cellulose and lignin nanoparticles as main products, but also aim to recover and benefit from other biomass components using only water‐based processes. Sequential pressurized liquid extractions and diluted acid and alkaline treatments were carried out to fractionate elephant grass biomass, yielding (for every 100 g of biomass): 30 g of cellulose pulp (converted to 9 g of cellulose nanocrystals and 9 g of cellulose nanofibers); 10 g of lignin (used to produce 8.5 g of stable colloidal lignin nanoparticles by probe‐sonication in water); 7.5 g of extractives (e.g. sterols and phenolics) and 23 g of xylose (converted to 4.1 g of furfural). Alternatively, to allow for the flexible use of the cellulose fraction in the proposed biorefinery, 22 g of glucose could be produced by enzymatic hydrolysis. The results demonstrate that water‐based processes are suitable for a holistic use of biomass, providing a comprehensive set of high‐value‐added co‐products that are renewable and cost‐effective chemical, cosmetic, food, polymer and pharmaceutical solutions.

Vegetation management shapes arthropod and bird communities in an African savanna.

Habitat heterogeneity is a key driver of the diversity and distribution of species. African savannas are experiencing changes in their vegetation structure causing shifts towards increased woody plant cover, which results in vegetation structure homogenization. Given the impact that increasing woody plant cover has on patterns of animal use, resource managers across Africa are implementing habitat management practices that are intended to reduce woody plant cover. To understand the ecological implications of various habitat management practices on arthropod and bird communities, we leveraged large-scale tree clearing and subsequent mowing in an African savanna to understand how changes in both the herbaceous layer and woody plant cover (i.e., structural heterogeneity) may shape arthropod and bird communities at the local scale. We focused on four replicated treatments: (1) annual summer mow, (2) annual winter mow, (3) >5 years since last mow (rest), and (4) an adjacent unmanipulated savanna to act as a control. We found that the mowing treatments significantly influenced vegetation structure both with respect to tree density and herbaceous layer. Both arthropod and bird community composition varied across treatments. Grass biomass was the best predictor of arthropod richness and abundance, with arthropods selecting for areas with high biomass. Insectivorous bird richness and abundance was driven by tree density (i.e., perching locations) and not arthropod abundance. Our results suggest that vegetation management practices contribute to habitat heterogeneity at the landscape scale and increase bird species richness through species turnover. However, we caution that if a single vegetation management practice dominates the landscape, it is plausible that it could lead to the simplification of the avian community.

Whole-soil warming shifts species composition without affecting diversity, biomass and productivity of the plant community in an alpine meadow.

The structure and function of plant communities in alpine meadow ecosystems are potentially susceptible to climate warming. Here, we utilized a unique field manipulation experiment in an alpine meadow on the Qinghai-Tibetan Plateau and investigated the responses of plant species diversity, composition, biomass, and net primary productivity (NPP) at both community and functional group levels to whole-soil-profile warming (3-4 °C across 0-100cm) during 2018-2021. Plant species diversity, biomass and NPP (both above- and belowground) at the community level showed remarkable resistance to warming. However, plant community composition gradually shifted over time. Over the whole experimental warming period, aboveground biomass of legumes significantly decreased by 45%. Conversely, warming significantly stimulated aboveground biomass of forbs by 84%, likely because of better growth and competitive advantages from the warming-induced stimulation of soil water and other variables. However, warming showed minor effects on aboveground biomass of grasses and sedges. Overall, we emphasize that experimental warming may significantly affect plant community composition in a short term by triggering adjustments in plant interspecific competition or survival strategies, which may cause potential changes in plant productivity over a more extended period and lead to changes in carbon source-sink dynamics in the alpine meadow ecosystem.

Leachate characteristics, dry matter yield of Urochloa decumbens and properties of two contrasting soils irrigated with sludgewater in columns

AbstractIncreasing demands on freshwater and challenges in disposal of wastewaters encourage their use for irrigation. The study evaluated the effects of irrigation of signal grass (Urochloa decumbens) with sludgewater on leaching, uptake and retention of a range of elements in two contrasting soils in columns. The grass was grown on a sandy loam and a clay soil packed in plastic columns and irrigated for 119 days with either undiluted, diluted sludgewater or tap water. The sludgewater had a pH of 6.9 and high aluminum (Al), manganese (Mn), iron (Fe), and boron (B). Analyses were conducted on leachates, above‐ground plant biomass (two harvests), and soils at the end of the experiment. Sludgewater treatments increased grass biomass yield and uptake of nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) in both soils with a greater nutrient uptake from the clay than the sandy loam. The application of sludgewater increased Mn and reduced P (sandy loam only) in the leachate with no effects on Al, Fe, or B. Uptake of Al, Fe, and B was increased by sludgewater application. Even when diluted, the sludgewater increased extractable Mn, particularly in the clay soil. The findings showed that irrigation of the soils with sludgewater increased Mn and B concentrations and uptake by signal grass, with no negative effects on biomass production. Leaching and accumulation in the soils of toxic elements were minimal in the short term. Sludgewater can therefore be used to grow signal grass in both soils although these effects need to be evaluated under field conditions.

Simulation of Crop Productivity for Guinea Grass (Megathyrsus maximus) Using AquaCrop under Different Water Regimes

The perennial herbaceous forage crops’ (PHFC) biomass as bioindustry feedstock or source of nutrients for ruminants is very important from their final utilization point of view. In 2022, the AquaCrop-FAO version 7.0 model has been opened for PHFC. In this context, this study aimed to test for the first time the ability of the AquaCrop-FAO model to simulate canopy cover (CC), total available soil water (TAW), and biomass (B) of Guinea grass (Megathyrsus maximus cv. Agrosavia sabanera) under different water regimes at the Colombian dry Caribbean, South America. The water regimes included L1—irrigation based on 80% field capacity (FC), L2—irrigation based on 60% FC, L3—irrigation based on 50% FC, L4—irrigation based on 40% FC, L5—irrigation based on 20% FC, and L6—rainfed. The AquaCrop model uses the normalized water productivity—WP* (g m−2)—to estimate the attainable rate of crop growth under water limitation. The WP* for Guinea grass was 35.9 ± 0.42 g m−2 with a high coefficient of determination (R2 = 0.94). The model calibration results indicated the simulated CC was good (R2 = 0.84, RMSE = 17.4%, NRMSE = 23.2%, EF = 0.63 and d = 0.91). In addition, cumulative biomass simulations were very good (R2 = 1.0, RMSE = 5.13 t ha−1, NRMSE = 8.0%, EF = 0.93 and d = 0.98), and TAW was good (R2 = 0.85, RMSE = 5.4 mm, NRMSE = 7.0%, EF = 0.56 and d= 0.91). During validation, the CC simulations were moderately good for all water regimes (0.78 < R2 < 0.97; 12.0% < RMSE < 17.5%; 15.9% < NRMSE < 28.0%; 0.47 < EF < 0.87; 0.82 < d < 0.97), the cumulative biomass was very good (0.99 < R2 < 1.0; 0.77 t ha−1 < RMSE < 3.15 t ha−1; 2.5% < NRMSE < 21.9%; 0.92 < EF < 0.99; 0.97 < d < 1.0), and TAW was acceptable (0.70 < R2 < 0.90; 5.8 mm < RMSE < 21.7 mm, 7.6% < NRMSE < 36.7%; 0.15 < EF < 0.58 and 0.79 < d < 0.9). The results of this study provide an important basis for future research, such as estimating biomass production of high-producing grasses in tropical environments, yield effects under scenarios of climate variability, and change based on the presented parameterization and considering a wide range of environments and grazing variations.

Soil microbial and macroinvertebrate functional diversity in response to Zokor disturbance in Tibetan alpine meadow

Soils contain a remarkable diversity of organisms that are important regulators of ecosystem functions. However, the knowledge of how the environment shapes biodiversity patterns below ground remains limited in alpine areas of the Tibetan Plateau. Here, we conducted a microhabitat scale study (400 m2 plot) integrating data on soil and plant community characteristics to explore the driving forces of functional diversity of soil microbial and macroinvertebrate communities under disturbance by plateau zokor (Eospalax baileyi), a subterranean rodent inhabiting the Tibetan Plateau. The results show that plateau zokor disturbance led to a decline in the belowground biomass of grasses, whereupon the total belowground plant biomass and soil organic carbon decreased significantly. The functional diversity of soil microbial and macroinvertebrate communities was significantly increased under plateau zokor disturbance. Redundancy analysis indicated that soil moisture, temperature and compaction, in combination with plant species richness and belowground biomass of forb were the most important factors in driving soil microbial and macroinvertebrate functional diversity. Piecewise structural equation modeling (SEM) revealed that plateau zokor mound disturbance had positive effects on the functional diversity of soil microbial and macroinvertebrate communities by regulating soil physical properties (moisture, temperature, and compaction) and plant species richness within the habitat. Further, zokor disturbance affected the functional diversity of soil microbial and macroinvertebrate communities indirectly via regulating soil organic carbon. Our study provides evidence that the functional diversity of microbes is more driven by environmental changes than those of macroinvertebrates.

Efficacy of Pendimethalin Rates on Barnyard Grass (Echinochloa crus-galli (L.) Beauv) and Their Effect on Photosynthetic Performance in Rice

Pendimethalin herbicide toxicity to rice plants and barnyard grass invasion have increasingly affected the productivity of direct-seeded rice (DSR) in the fields. Whether and how to promote DSR productivity and sustain weed management depend on the appropriate pre-emergence herbicide application rate to minimise its toxicity in the rice ecosystem. Pot experiments were conducted to determine the effects of pendimethalin rates (1.5, 1.75, 2.0 kg a.i. ha−1, two control treatments include the untreated control and the treated control with 1.5 kg a.i. ha−1 S-metolachlor) on barnyard grass (Echinochloa crus-galli (L.) Beaux) and their potential toxicity risk to photosynthetic performances of rice (Topaz and Sen pidao). All the pendimethalin treatments provided excellent control of barnyard grass. Among the treatments, 1.5, 1.75, 2.0 kg a.i. ha−1 pendimethalin and 1.5 kg a.i. ha−1 S-metolachlor (treated control) decreased leaf area of barnyard grass significantly by 38.9, 49.6, 49.6 and 46.2%, respectively, compared with the untreated control at 40 days after sowing (DAS). The above-ground biomass of barnyard grass significantly decreased by 40% (1.48 g plant−1) with 2.0 kg a.i. ha−1 pendimethalin and by 46.2% (1.33 g plant−1) when 1.5 kg a.i. ha−1S-metolachlor was applied at 40 DAS compared with the untreated pots. Higher pendimethalin rates increased toxicity in Topaz and Sen pidao varieties, and 2.0 kg a.i. ha−1 pendimethalin significantly reduced effective quantum yield (light-adapted) of photosystem (PS) II by 18% (0.58) and 19% (0.52), respectively, compared with the untreated control. Application of 2.0 kg a.i. ha−1 pendimethalin rate significantly decreased the maximum quantum yield (dark-adapted) of Sen pidao (0.66) compared with 1.5 kg a.i. ha−1 pendimethalin (0.68) including the untreated control. All pendimethalin treatments suppressed above-ground biomass at 55 DAS, but above-ground biomass of barnyard grass significantly decreased by 59.9% when 2.0 kg a.i. ha−1 pendimethalin was applied compared with the untreated control. Although application of 1.5 kg a.i. ha−1 pendimethalin rates reduced the effective quantum yield (light-adapted) of photosystem II of Sen pidao (0.55) by a small percentage (8%) than Topaz (0.65), it was non-toxic for both varieties compared with 2.0 kg a.i. ha−1 pendimethalin. Therefore, the use of 1.5 kg a.i. ha−1 pendimethalin can be used for effective weed management in the direct seeding of rice at an early growth stage.

Effects of precipitation and grazing on the diversity and productivity of desert steppe

AbstractThe variability of annual precipitation and grazing are primary drivers shaping the structure and function of plant communities in grasslands. Yet it remains unclear on a mechanistic understanding of how annual precipitation and grazing affect the plant community structure, function, and their linkage via direct or indirect pathways. We measured the plant community structure (plant traits, species abundance, and plant diversity), total aboveground biomass, total cover, and species covers in plant communities in responses to annual precipitation variability from 2014 to 2017 and grazing pressure comprising 0, 0.93, 1.82, and 2.71 sheep ha−1 in a desert steppe. Two‐way ANOVAs, ordinary least square regressions, and the structural equation modeling (SEM) were used to test the impacts of annual precipitation variability and grazing pressure on the plant community structure and function. Results showed that higher annual precipitation of 2016 and 2017 increased the relative abundances of forbs; grazing pressure increased the relative abundances of dominant grasses [Stipa breviflora Griseb. and Cleistogenes songorica (Roshev.) Ohwi], but decreased those of subdominant forbs (Convolvulus ammannii Desr. and Artemisia frigida Willd.). Plant traits, such as leaf nitrogen concentration, regulated plant species abundance directly or indirectly via affecting sheep diet selection. Annual precipitation variability and grazing pressure independently regulated plant diversity, aboveground biomass, and total cover, which the former had larger effects. There was slower decrease in grass biomass than that in forb biomass with increasing grazing pressure, indicating that dominant grasses are resilient to grazing but subdominant forbs are sensitive due to their distinct difference in sward palatability. The positive correlation between plant diversity and aboveground biomass was driven by both annual precipitation variability and grazing pressure. These highlight direct and indirect (via traits and abundances of plant species) effects of annual precipitation and grazing in shaping the structure and function of desert steppe ecosystems.

Valorization of Lignin Based Nanoparticle from Grass Biomass: An Overview on Synthesis, Characterization and Application

The Lignin-related nanomaterials have received a lot of attention from the academic and industry communities in the present nanotechnology research area. Advanced performance can be provided by converting lignin into micro and nanostructures, which may be formed using practical standard apparatus. To improve the functionality of the applications, tunable lignin nanoparticles may also be produced. Because lignin contains a variety of chemical moieties and has a unique network structure, it has useful qualities such UV absorbance, biodegradability, stabilizing and reinforcing effects, as well as anti-fungal and antibiotic action. Thus, the nanoscale transformation of lignin and its translation into nanomaterials might definitely open up new possibilities for the development of novel materials with intriguing features.

Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application

Grass and other herbaceous biomass are abundant, but often under- or not utilized as a renewable resource. Here, the production of biochar from extensive late-harvest grass via multiple thermochemical conversion technologies was investigated at lab and farm scale for use in soil applications. While biochar is a product with highly diverse potential applications, it has a multitude of benefits for agricultural usage as a soil amendment, if the quality adheres to certain limit values of potentially toxic constituents. The results show that the biochar can adhere to all limit values of the European Biochar Certificate (EBC) for utilization in agriculture. Generally, the contents of heavy metals were well below the proposed EBC limits and very low PAH concentrations in the biochar were achieved. The high ash content in the grass of 7.71 wt%db resulted in high nutrient concentrations in the biochar, of benefit in soil applications, but the ash also contains chlorine, nitrogen and sulphur, which presents a challenge for the operation of the thermochemical processes themselves due to corrosion and emission limits. In the farm-scale processes, ash retention ranged from 53.7 wt%db for an autothermal batch process, reaching up to 93.7 wt%db for a batch allothermal process. The release of Cl, N and S was found to differ substantially between processes. Retention ranged from 41.7%, 22.9% and 27.6%, respectively, in a continuous allothermal farm-scale pyrolysis process, to 71.7%, 49.7% and 73.9%, with controlled lab-scale pyrolysis at 450 °C, demonstrating that process optimization may be possible.

Exploration of the bioenergy potential of Dactyloctenium aegyptium through pyrolysis, kinetics, and thermodynamic parameters to produce clean fuels and biochemicals

The Egyptian grass (Dactyloctenium aegyptium) is a common low-cost coarse grass which is adapted to poor soils. The biomass of the Egyptian grass may be used to produce cleaner and sustainable fuels through pyrolysis without causing any contradictory impact on the land for food. It is profound to understand the thermochemical character of the Egyptian grass biomass for its efficient thermal conversion to clean fuels and chemicals. The current study elucidated the pyrolysis process of this biomass for the very first time based on the pyrolysis data. Heat-dried powdered biomass of Dactyloctenium aegyptium was pyrolyzed at 10 min−1, 30 min−1 and 50 °C min−1 in a simultaneous Thermogravimetry–Differential Scanning Calorimetry analyzer (TGA-DSC) under nitrogen atmosphere. Isoconversional models of Kissenger-Akahira-Sunose (KSA), Flynn–Wall–Ozawa (FWO) and first and second order reaction kinetics model were used to analyze the pyrolytic kinetic parameters. The pyrolysis of D. aegyptium grass biomass was shown to be a three-stage pyrolysis process where around 50 % of the product formation was happening within a narrow temperature range of 240–360 °C with the Activation energies ranged from 167 to 267 kJ mol−1 and thermodynamic parameters including 18.25–18.63 MJ kg−1 of high heating values, 169–177 kJ mol−1 of Gibb’s free energies, and 166–256 kJ mol−1 of reaction enthalpy have shown the outstanding pyrolysis and co-pyrolysis potential of Egyptian grass to produce clean fuels.

The effects of grass biomass preservation methods, organic acid treatment and press type on the separation efficiency in the green biorefinery

Processing green biomass into novel products provides opportunities to improve the sustainability of the bioeconomy. The objective of this study was to evaluate the effects of biomass types (fresh, frozen-and-thawed, dried-and-rehydrated and ensiled grass) as well as formic and propionic acid-based additive on the efficiency of liquid-solid separation and crude protein (CP) yield. Three different pressing methods for liquid-solid separation were used. All preservation methods improved biorefinery efficiency compared to fresh grass, and the effect of additive was more profound on the fresh biomass than other materials. However, due to lower CP concentration in the liquid, presumably caused by lower nitrogen solubility, the amount of CP retained in the liquid was not improved in response to the additive treatment. The type of processing technology plays a key role in the extraction of relevant compounds from biomass. With less efficient separation methods, the effects of pretreatments were more pronounced.

Phytoremediation and Nurse Potential of Aloe Plants on Mine Tailings

Mine tailings are a source of potentially toxic metals (PTMs) worldwide. Phytoremediation is a low-cost green technology that uses metal-tolerant plants to extract these contaminants and rehabilitate the soil. In mine tailing restoration efforts, it can be beneficial to introduce species that can facilitate the colonization of other plants (i.e., nurse plant syndrome). In this study, the phytoremediation and nursing potential of two species adapted to metalliferous soil, Aloe burgersfortensis and A. castanea, were evaluated for the first time. An experiment was performed with aloe plants grown in pots containing potting soil, platinum tailings, and gold tailings. Leaves were assessed for bioaccumulation of PTMs. Seeds of Bermuda grass and African daisy, two successional pioneers, were planted with the aloes and had their developmental parameters evaluated after 30 days. Allelopathic effects were also assessed, with seeds of the pioneer plants infused with root extracts of the aloes from the different soil treatments. A. castanea demonstrated greater potential for the bioaccumulation of Cd, Co, Mn, Ni, and Zn in the tailings. The presence of aloes benefited germination rates, leaf count, length, and plant biomass of grasses and daisies in the mine tailings, without significant allelopathic effects. Therefore, aloes-especially A. castanea-should be employed in the rehabilitation of metal-contaminated soils to extract metals and to aid the establishment of other species to enhance the phytoremediation processes.

Grazing patterns, diet quality, and performance of cow-calf pairs using continuous or rotational grazing in the Texas panhandle USA

This study 1) measured diet quality and performance of cow-calf pairs; and 2) compared defoliation patterns and changes in standing crop of functional groups relative to the proximity of water over a grazing season under continuous (CG) or rotational (HSD) grazing at the same stocking rate and stocking intensity. Eighty lactating cow-calf pairs were weighed and assigned among shortgrass-dominated rangeland pastures (three replicates per treatment). Standing crop by species was measured at study initiation and completion. Frequency of grazed plants was measured along 0.39km point transects radiating from water troughs. Cow and calf weights and average daily gains were compared between treatments. Mean dietary CP was higher for CG cattle. Forage quality for major species (blue grama and gummy lovegrass) did not differ between treatments. Y-intercepts of regression lines predicting probability of defoliation differed between treatments following the 1st, 6th, and 7th 16-day intervals of the 112-day grazing study. Final standing biomass of gummy lovegrass was lower in HSD. Final cool-season annual grass biomass was lower in CG. HSD grazing can regulate the frequency and timing of defoliation, thereby changing relative proportions of plant species, inter-species competition and animal performance over time.