Pennisetum Purpureum Research Articles

Accelerated aging of polymer composite from Pennisetum purpureum fibers with recycled low-density polyethylene

The use of natural fibers (NF) as reinforcement in polymer composites have been an interesting option to improve their mechanical properties and to decrease production costs since several crops can produce large amounts of NF with low cost. This is particularly attractive for polymer waste recycling that depends of the production of cheap materials to be economically viable. Elephant grass ( Pennisetum purpureum schum) is a tropical climate plant of fast growth with high potential for production of NF. However, studies on the use of P. purpureum fibers as reinforcement in polymers, mainly for recycled polymers, have been restricted. The aims of this study was to evaluate the action of the P. purpureum fibers on the properties of composites using matrix of low-density polyethylene waste (LDPE-w) as well as to verify the behavior of recycled polymer when submitted to the accelerated photochemical aging using UVA radiation. LDPE-w and LDPE-w composite with P. purpureum fibers (LDPE-composite) were analyzed at different aging times by tensile and impact tests, melt flow rate, scanning electron microscopy and Fourier transform infrared. It was verified that P. purpureum fibers induce defects in matrix of LDPE-w, decreasing the performance of mechanical properties. Similar effect also occurs when LDPE-w is submitted to the first hours of accelerated aging. On the other hand, effects of stabilization of the degradation on the polymer matrix can be attributed to the P. purpureum fibers at high aging times. Thus, P. purpureum presents high potential for use as reinforcement in recycled thermoplastic waste.

PEMBUATAN KEBUN RUMPUT ODOT (Pennisetum Purpureum cv. Mott) SEBAGAI PAKAN HIJAU TERNAK RUMINANSIA DI DESA URAUR KECAMATAN KAIRATU KABUPATEN SERAM BAGIAN BARAT

Animal feed forage is the main source of food that is needed the most by ruminant livestock to survive, breed, and increase their productivity. One of the high-quality grass that is most often given to the livestock is bermudagrass (pennisetum purpureum cv. Mott.), because it has a high nutritional content and is palatable. The purpose of community service activity in Uraur village, Kairatu, West Seram Region in the form of education and production of cultivation garden for high quality grass such as bermudagrass (pennisetum purpureum cv. Mott.), is to increase the knowledge of breeders and to provide fresh greed feed with high nutritional value, in order to fulfill the need of ruminant livestock. This community service activity uses the participatory observation method, involving villagers that own livestock in Uraur Village as respondents and partners. This activity increases the knowledge of the breeders because by planting high quality grass (bermudagrass) and using it as fodder they could increase their livestock’s productivity, which in return contribute to the wellbeing of cattle (ruminant livestock) breeders. It most likely happens because bermudagrass has 10 -15 % protein content depending on harvest age, and has low content of crude fiber. The production of bermudagrass could reach up to 60 Ton/Ha/Year. This community service could increase the knowledge about cultivation of high quality grass (bermudagrass), and the availability of sample grass field for breeders in Uraur Village.

Anaerobic co-digestion of elephant dung and biological pretreated Napier grass: Synergistic effect and kinetics of methane production

Elephant dung (ED) and Napier grass (NP) are used as waste-to-energy resources that help in waste management and reduce greenhouse gas emissions, in accordance with Sustainable Development Goal 13 (SDG 13). In this study, anaerobic co-digestion of ED and NP (with and without biological pretreatment) was conducted under various mixing ratios. The biological pretreatment of NP was performed using the microbial activator super LDD1 (mixed culture microbial sludge) enzyme before further biogas production. The results confirmed that LDD1 enzymatic microbes increased methane production capacity by 1.95 times compared to untreated NP. Moreover, the data revealed that a NP/ED ratio of 1:1 with a 14-day pretreatment duration yielded the highest cumulative methane production of 234.8 ± 5.9 mL-CH4/g-VS, a 99.2% increase. The synergistic index results showed that substrate pretreatment had the most significant effect on methane yield, with the maximum synergistic index equaling 1.53. The Gompertz model outperformed the Logistic model in determining the reaction's kinetic parameters, with R2 > 0.995.

Effect of rice bran crude lecithin blended diet on rumen ecology, metabolic profile, and milk fat indices affecting human health

AbstractTwo experiments are conducted to find out the effect of rice bran crude lecithin on rumen ecology, milk fat quality, metabolic indices, and leptin (LEP) gene expression. In first experiment, 12 crossbred calves are randomly divided into two groups, that is, RBCL‐0 and RBCL‐6, and they are fed wheat straw based diet with concentrate mixture containing 0% RBCL (CM1) and 6% RBCL (CM2), respectively, for 120 d for rumen fermentation study. Ruminal ammonia‐N and short chain fatty acids and rumen microbes are nonsignificantly affected in RBCL calves. In second experiment, 12 lactating cows are randomly divided into RBCL‐0 and RBCL‐6 groups and fed CM1 and CM2 concentrate along with napier grass as roughage. In milk fatty acid profile, C16:1 fatty acid is significantly lower whilecis‐C18:1 is significantly higher in the RBCL supplemented cows. The atherogenic index and thrombogenic index are 16 and 19% lower while health promoting index, polyunsaturated saturated fatty acids, and hypocholesterolaemic/hypercholesterolaemic are 16, 10, and 16, respectively, higher in RBCL‐6 cows. The mean nonesterified fatty acid and β‐hydroxy butyric acid value is lower while LEP gene expression is higher in RBCL supplemented cows than control cows. The milk income is higher in RBCL cows. Finally, it can be concluded that RBCL at 6% in concentrate mixture of dairy ration do not adversely affect the rumen ecology. Although RBCL has capacity to enhance health properties of milk fat along with profitability, still more studies are warranted.Practical applications: Cow milk has always been an important component of the human diet in the world. The milk composition, especially fat, is directly influenced by feeding regime in dairy animals. In the milk fat, the unsaturated fatty acids (mainly polyunsaturated fatty acids) help in improving the health condition of consumers along with the keeping quality of milk. In this series, rice bran crude lecithin was used in the dairy ration and found that it altered certain metabolic parameters and gene expression, which may be beneficial for animal health without altering rumen fermentation. Although RBCL substantially modify the milk fatty acid profile and improves the fat indices which will enhance the human health by protecting them from cardiovascular diseases.

Analysis of rumen degradation characteristics of forage crude protein in goat

The quality of feed given to ruminants can be determined from the degradation of nutrient content in the rumen. This study aimed to determine the pattern of forage degradation and the characteristics degradation of crude protein in the rumen using the in sacco method. The study used 4 fistulae kacang goats with an average body weight of 14.57 kg. The forage used consisted of R1: elephant grass (Pennisetum purpureum), R2: mini elephant grass (Pennisetum purpureum cv. Mott), R3: guinea grass (Panicum maximum), and R4: signal grass (Bracharia decumbens). The nylon bag is made of polyester measuring 8x4 cm with a porosity of 40 µm. Feed samples were put into the rumen and incubated for 0, 4, 8, 12, 24, 48, and 72 hours. The parameters measured were consumption, patterns, and forage degradation characteristics by calculating the values of a, b, c, a+b, lag time, and ED. Determination characteristics of feed degradation in the rumen by in sacco method will be analyzed. The results showed that the characteristics of crude protein degradation had significant differences in fraction values a, b, a+b, and lag time (P<0.05), while c and ED did not have significant differences (P>0.05). In conclusion the crude protein of the degradation characteristics in the rumen were: elephant grass (a: 9.88%, b: 64.37%, and c: 0.06/h-1), mini elephant grass (a: 16.50%, b: 45.24%, and c: 0.05/h-1), guinea grass (a: 7.42%, b: 68.24%, and c: 0.05/h-1), and signal grass (a: 6.79%, b: 56.19%, and c: 0.07/h-1). So, grass can provide sufficient protein for microbial growth in the rumen for ruminants.

NUTRITIONAL COMPOSITION OF CUBA OM-22 HYBRID GRASS (Pennisetum purpureum Schumach x Pennisetum glaucum L.) AT THREE CUTTING AGES

At the Central Experimental Station of the Ecuadorian Amazon of INIAP, the nutritional composition of the forage Pennisetum purpureum Schumach x Pennisetum glaucum L was evaluated. (Cuba OM-22) in different cut-off ages (30, 45 and 60 days). There were 12 plots of 6m2 each of approximately six months of establishment, a completely randomized block design (DBCA) was used with three treatments and four repetitions, the variables were subjected to an analysis of variance, the means were evaluated with Tukey's test at 0.05%, in addition a regression and correlation analysis was performed. All the variables studied except dry matter and acid detergent lignin presented significant and highly significant differences; at 30 days of cut-off, the highest nutritional values were found, ash (19.04%), ethereal extract (2.84%), protein (14.20%), FDA (34.67%) and FDN (56.29%). It is concluded that in the forage Cuba OM-22, at 30 days of cutting age presents the highest nutritional values, however, it is considered necessary an adequate management of the crop to guarantee the agronomic development and the persistence of the crop.

A Study of the Feed Management Practices of Private Elephant Camps in Chiangmai Province

Captive elephant must be properly fed to meet their nutritional demands, supporting optimal growth and development to achieve their providing conservation through tourism. This study aimed to revision of the feed management practices of private elephant camps in Chiangmai province. An archival review and in depth interviews of key informants involving the elephant camps owners or managers located in Chiangmai were conducted. The interview showed that staple roughage of most camps was hybrid napier grass while once is sweet corn soilage. The majority of the large elephant camps with more than 30 elephants which were fed by the camp. Elephants' dietary requirements were addressed under the supervision of veterinarians. The delivery of roughage of large camps coincided with small camp size which the middle man played an important role for gathering, harvesting, transporting and feeding the roughage to the elephants raised in the camps. The diary was fed 10 percent of their weight or about 100-120 kg roughage per individual. Most of the camp, roughage was divided into four to five meals each day. The study's findings for the tiny elephant camps' food management revealed that including elephants in greeting activities for eco-tourists so that they can eat while traveling the hiking trails. The camp also bought bananas and sugar cane from local farmers to sell to visitors for the purpose of feeding the elephants. However, a COVID-19 outbreak that occurred during the research period prevented the elephant camp from earning money from the tourism sector, which reduced the amount of food available.

The influence of napier grass biomass mixed feed on the biorefinery indicator for Nile tilapia production.

Aquaculture is vital for feeding a growing population as aquatic creatures require more protein. Utilizing protein-rich biomass for feeding animals is a possible solution. Biorefinery technology can extract protein and non-protein components from biomass, creating an economically feasible value chain. This study replaced fish feed with napier grass and used a compensatory response to reduce the cost of feeding Nile tilapia. The trial involved dividing mono-sex male Nile tilapia, initially weighing between 11.10 and 13.60 g/f, into four groups with three replications based on their feeding regime. Therefore, in the study, four groups of Nile tilapia were fed different diets for 90 days. The control group (T1) received a commercial floating pellet diet throughout the trial. Group T2 and T3 received a mix of commercial floating pellet diet and napier grass in varying proportions, and group T4 was fed with only napier grass throughout the trial. The study found that groups T2 and T3 had remarkable fish growth performance, high digestibility of napier grass, and lower feed prices with the highest benefit-cost ratios. The percentage of edible flesh and Hepatosomatic Index (PT2) were higher in group T2 than T3. Cellulase activity decreased with the frequency of napier grass intake, and the amylase activity was higher in T2 than T3, which also had the highest growth performance and feed utilization. Therefore, the study suggests that the optimal feeding regimen for Nile tilapia is T2 or T3, which promotes growth and is cost-effective.

Can N2 fixation by forage legumes build soil organic matter to rival fertilizer N in a tropical forest biome?

Fertilization of pastures with nitrogen (N) can increase animal productivity and may also increase the stocks of soil carbon (C). Recently stoloniferous forage legumes have been used to develop productive sustainable mixed pastures in the Atlantic forest biome. The objective of this study was to compare the impact over 24 years on soil C and N stocks of a productive N-fertilized pasture of Urochloa brizantha cv. Marandu with a mixed forage peanut (Arachis pintoi)-Marandu grass pasture introduced 8 years after an N-fertilized elephantgrass (Pennisetum purpureum) pasture. The pastures were rotationally stocked by Nellore cattle a green-forage allowance equivalent to 4% of body weight and animal performance was continuously monitored. Soil samples were taken at the start of the study and after 8 and 24 years of grazing and analyzed for total C and N and 13C abundance. In 8 years, the stocks of soil organic matter (SOM – 0-30 cm) increased by 4.4 Mg C and 0.58 Mg N ha−1 under the elephantgrass pasture and by 10.4 Mg C and 1.23 Mg N ha−1 under the Marandu grass pasture, both fertilized with 160 kg N ha−1 yr−1. Over the subsequent 16 years, SOM stocks under the Marandu grass fertilized with 120 kg N ha−1 and the mixed forage peanut-Marandu pasture which replaced elephantgrass attained similar stocks of soil C of 51.8 and 52.5 Mg C ha−1 respectively, approximately 12 Mg C greater than under the native vegetation. The 13C abundance of the soil samples indicated that the C4 grass roots made an insignificant contribution to soil C below 30 cm depth. The results show that the N2-fixing forage peanut was just as effective in accumulating SOM as an annual application of 120 kg N fertilizer ha−1 and indicated that after 24 years of these pastures there was little further SOM accumulation.

Ex Situ Catalytic Pyrolysis of Invasive Pennisetum purpureum Grass with Activated Carbon for Upgrading Bio-Oil

Energy demands keep increasing in this modern world as the world population increases, which leads to a reduction in fossil fuels. To resolve these challenges, Pennisetum purpureum, an invasive grass in Brunei Darussalam, was examined as the feedstock for renewable energy through a catalytic pyrolysis process. The activated carbon was applied as the catalyst for a simple and economical solution. The catalytic pyrolysis was executed at 500 °C (the temperature for the highest biofuel yield) for both reactors to produce the highest amount of upgraded biofuels. The biochar produced from the non-catalytic and catalytic pyrolysis processes showed a consistent yield due to stable operating conditions, from which the activated carbon was generated and used as the catalyst in this work. A significant amount of improvement was found in the production of biofuels, especially bio-oil. It was found that for catalysts, the number of phenolic, alcohol, furans, and ketones was increased by reducing the amount of acidic, aldehyde, miscellaneous oxygenated, and nitrogenous composites in bio-oils. The highest amount of phenolic compounds was produced due to a number of functional groups (-C=O and -OH) in activated carbon. The regenerated activated carbons also showed promising outcomes as catalysts for upgrading the bio-oils. The overall performance of synthesized and regenerated activated carbon as a catalyst in catalytic pyrolysis was highly promising for improving the quality and stability of bio-oil.

Application of Salicylic Acid and Gibberellic Acid Increase Stem Cutting Growth of Pennisetum purpureum cv. Mahasarakham and Pennisetum purpureum x Pennisetum americanum

The Napier grass continues to be a popular forage crop in Nakhonsawan Province and other areas in the northern and east-northern parts of Thailand. Increasing the growth and biomass of Napier grass growing in low-quality sandy soil will increase the economic value of this plant. The stem cutting of two cultivars of Napier grass, cv. Pakchong 1 (Pennisetum purpureum x Pennisetum americanum) and sweet grass (Pennisetum purpureum cv. Mahasarakham), were exposed to two plant growth regulators, gibberellic acid and salicylic acid, and two application methods, soaking for 24 hr and watering after inoculation into the soil, were studied. For one plant growth regulator test, the most appropriate concentration of gibberellic acid and salicylic acid were 0.01 and 100 mg/L, respectively, for the soaking and watering method. There was an interaction between the combination of plant growth regulator type and application method for both cultivars. The best stimulation effect for sweet grass was soaking with 100 mg/L salicylic acids only. The response of Napier grass cv. Pakchong 1 was different. Soaking with 0.01 mg/L gibberellic acid and watering with 0.01 mg/L gibberellic acid was suitable for increasing shoot and root length while soaking with 0.01 mg/L gibberellic acid and watering with 100 mg/L salicylic acid was suitable for increasing fresh and dry weight. This information will be useful for stimulating the growth of Napier grass in agricultural purposes.

Silage quality based on the physical and chemical of several napier grass varieties (Pennisetum purpureum) supplied with different levels of pollard

Making silage is one method for storing feed during the dry season. To preserve the ingredients for feed, silage is made by carefully controlling the fermentation of forage with a high water content. The idea behind making silage is to create anaerobic conditions in which lactic acid bacteria can grow in order to stop the decay process. Fresh fodder, such as grasses, is commonly used in silage. The goal of this study was to assess the physical and chemical properties of various types of Pennisetum purpureum sp. that had been supplemented with varying amounts of pollard. Factorial Completely Randomized Design (CRD) in 2 x 3 Factorial is the design used in this experiment. The first factor involves two kinds of Pennisetum purpureum sp., specifically Pennisetum purpureum cv. Mott and Pennisetum purpureum with gamma radiation (cv. GU). The second element is the level of pollard supplementation, which consists of 0%, 3%, and 6% with 5 replications. The results were then examined for the physical qualities of the silage quality, including the silage’s color, flavor, texture, and fungus content. The silage’s detected chemical properties included pH, DM, OM, CP, CF, and EE silage. The outcomes demonstrated that silage with good physical quality was produced by the types and pollard supplementation treatments. Increased pollard supplementation levels were negatively correlated with pH (P 0.05). When pollard supplementation was increased, the levels of lactic acid, DM, and CP considerably increased linearly (P 0.05), CF and EE levels dramatically decreased (P 0.05), while OM levels did not significantly differ (P > 0.05). It was determined that adding pollard at a level of 6% and using gamma radiation on Pennisetum purpureum in combination are treatments that result in crops with a color that is similar to silage material, an acidic odor, a non-slimy texture, and no fungus.

Fermentation quality of ratoon rice fermented with fermented juice of epiphytic lactic acid bacteria from tropicalgrass

This study aimed to determine the quality of fermented ratoon paddy silage as ruminant feed. The paddy material was obtained from rice fields in the Sukoharjo, Central Java, Indonesia. Turiang padi (Oryza sativa) at the cutting age of 14 days, with the Inpari 32 variety. The addition of an accelerator of Lactic Acid Bacteria or FJLB (fermented juice of epiphityc lactic acid bacteria) from Elephant Grass Extract (Pennisetum purpureum) and Odot Grass (Pennisetum purpureum CV. Mott) were incubated for 2 days. This research was conducted experimentally using a completely randomized design (CRD) with 5 replications for each treatment. The treatments consisted of no additives (T1), FJLB additives from elephant grass (T2) and odot grass (T3). FJLB was added as much as 1% of fresh weight. Silage fermentation was carried out for 21 days at room temperature. All data obtained were analyzed using the R Studio program. The Flieg point value showed the silage quality in the good and very good range. Butyric acid production is low and still within standard limits. The production of lactic acid was higher (P<0.05) in the silage of paddy ratoon which received additional silage additive from FJLB. It could be concluded that the addition of FJLB was able to improve the quality of the fermented ratoon rice.

Thermogravimetric assessment for combustion characteristic of torrefied pellet biomass from agricultural solid waste

This present paper is focused on the investigation of combustion characteristics of torrefied pellet biomass from agricultural waste. Four biomass pellet samples such as sugarcane bagasse, Napier grass, Palm Empty Fruit Bunches, and Cassava stem were torrefied in a designed cylinder tubular pyrolysis reactor. The reactor was set up under 30 min of residence time, and the temperature reaction was varied at 200, 250, and 300 °C in an inert atmosphere. The torrefied products were then characterized in terms of their psychochemical properties such as proximate, ultimate, calorific value, and combustion properties. The combustion properties of raw and torrefied biomass pellets during the combustion process were investigated by the thermogravimetric analyzer Exstar SII TG/DTA7300. The samples were heated at an ambient temperature up to 800 °C at a constant heating rate of airflow at 10 °C/min in airflow. The results showed that the moisture content and volatile matter of torrefied pellets decreased by 2 to 5% and 8 to 14%, subsequently. Otherwise, the fixed carbon content is up to three times higher than the raw material. The study conclusively that torrefaction can also able to enhance combustion performance in terms of ignition and burnout temperature, ignition and burnout index, and combustion rate. The results shows that, the ignition and burnout temperatures of torrefied pellets are higher than raw material. The ignition and combustion index of torrefied pellets are lower than raw material, and the torrefied pellets have a longer burning time and a higher combustion temperature.

Prediction and optimization of syngas production from Napier grass air gasification via kinetic modelling and response surface methodology

In this research, a kinetic model was developed for Napier grass air gasification using Aspen Plus software and thereafter collated and validated with experimental results obtained from a lab-scale fluidized bed reactor. Herein, the model was further employed to investigate the effect of gasification operating parameters, including temperature (650–850) °C, equivalence ratio (0.2–0.4), and moisture content (0–18) wt.% on products’ yields and syngas quality. The model was segregated into four sections: the drying, devolatilization, combustion, and reduction sections. The outputs of tar, gas, and char from the devolatilization section were defined by external Microsoft Excel subroutine. Kinetic parameters were incorporated in the combustion and reduction sections to simulate tar cracking, oxidation, and reduction reactions. A good agreement was observed between the predicted and experimental results. Furthermore, response surface methodology (RSM) was employed to analyze the mutual effects of process variables and perform multi-objective optimization to maximize producer gas yield, higher heating value, carbon conversion efficiency, and cold gas efficiency by incorporating the predicted results from the developed kinetic model. The optimized syngas yield and HHV were 69.42 wt% and 8.14 MJ/Nm3 at 850 °C, 0.3021, and 15.69 wt% for temperature, ER, and moisture content, respectively.

Viability of Napier Grass Ash as Partial Substitute of Cement in CHB

The effects on the physical and mechanical properties of Napier grass ash (NGA) as substitute for ordinary Portland cement (OPC) on concrete hollow block (CHB) were investigated. Mix ratio of 1:2:4 with water-cement ratio of 0.60, and 10%, 15%, and 20% NGA replacements were adapted. Experimental procedures and testing conformed to American Society of Testing and Materials (ASTM) standards. Slump values, in comparison to control, showed a decline of 16.67%, 25%, and 58.33% for 10%, 15%, and 20% NGA replacements, respectively, which correlates to water absorption result. The denser the CHB, the lower the moisture content. Compressive strength results revealed that all NGA substitutes performed better than the control sample. NGA-20% had the highest compressive strength of 4.2 MPa (individual unit) and 3.9 MPa (average of 3 units) after 28 days of curing. Overall, NGA replacement was not viable for load-bearing but ideal for nonload-bearing CHB using the mix design.

In-Situ Digestibility of Selected Fibrous Feedstuffs at Varying Levels of Concentrate Supplementation in Rumen-fistulated Brahman Bull

A series of experiments were done to determine the effects of 20% and 40% levels of concentrate supplementation on the in-situ degradability of dry matter (DMD), organic matter (OMD), and neutral detergent fibre (NDFD) in a rumen-fistulated Brahman bull. Treatment diets included: T1—untreated rice straw, T2 – urea-treated rice straw, T3 – Napier soilage, T4 – Napier silage, T5 – sugarcane tops, and T6 – dried cogon grass. The nylon bags containing the treatment diets were incubated in the rumen at two periods: first at a 20% concentrate (20% of total diet D.M.) level, and second at a 40% concentrate (40% of total diet D.M.) level in a bull-fed Napier grass as basal diet. There were significant differencesin DMD and OMD among feedstuffs tested at a 20% level of concentrate supplementation; the highest was with Napier silage. Neutral detergent fibre (NDF) digestibility was highest with urea-treated rice straw (UTRS) and lowest in Napier silage and sugarcane tops. At a 40% level, in situ DMD, OMD, and NDFD decreased significantly with Napier silage, UTRS, and Cogon, respectively, which were associated with a drop in rumen pH. Most significant drop in NDF digestibility was with rice straw, Napier soilage, and Cogon. Hence, further study is recommended on evaluating fibre degradability and incubation.

Evaluation of the Mineral and Nitrogen Contents of Three Forage Crops (Vigna unguiculata (L.) Walp., Pennisetum purpureum Schum. and Hyparrhenia diplandra (Hack.) Stapf.) Grown in the Boundji area (Republic of Congo)

Pennisetum purpureum Schum., Vigna unguiculata (L.) Walp. and Hyparrhenia diplandra (Hack.) Stapf are fodder plants that can provide quality herbaceous above-ground phytomass for domestic animal feeding. They are used in degraded pasture restoration practices. The objective of this study was to evaluate the mineral elements and nitrogenous matter of these three forage crops. The latter were planted in the pedoclimatic conditions of the Boundji area. Phytomass samples were taken two months after planting by sowing seeds for Vigna unguiculata (L.) Walp., by cuttings for Pennisetum purpureum Schum. and by splitting the stumps for Hyparrhenia diplandra (Hack.) Stapf. The samples were oven-dried at 70 °C to constant weight and chemically analysed. The results obtained show that the mineral elements and nitrogenous matter vary from one forage species to another. Vigna unguiculata (L.) Walp. is the richest forage species in total nitrogenous matter (16.43 ± 2.43%) and digestible nitrogenous matter (117.50 ± 22.64 g/k DM). It provides excellent quality fodder capable of meeting the needs of maintenance, growth, reproduction, gestation and milk production in cattle. Pennisetum purpureum Schum. is the richest grass in total nitrogenous matter (8.43 ± 1.81%) and digestible nitrogenous matter (43.18 ± 16.83 g/kg DM). Pennisetum purpureum Schum. and Hyparrhenia diplandra (Hack.) Stapf produce good quality fodder to meet the vital needs of cattle. These results could be used for the improvement of degraded pastures in order to sustainably manage the pastoral ecosystem.

Biomass Yield, Quality, and Soil Nutrients of Pasture Influenced by Farmyard Manure and Enrichment Planting

Grazing land remains the major feed source for livestock for smallholder farmers in Ethiopia; however, its productivity is low and it is prone to degradation. A field experiment was conducted to evaluate the effects of farmyard manure (FYM) and enrichment planting with improved forages on biomass yield, nutritional value, and soil chemical properties in dryland areas of northwestern Ethiopia. The experiment was carried out using a randomized complete block design with three replications for 2 yr. Natural pasture plots were seeded and treated with Napier grass (Pennisetum purpureum) or desho grass (Pennisetum pedicellatum), Napier or desho + FYM, Napier or desho + Desmodium, and Napier or desho + FYM + Desmodium; untreated plots were used as controls. In the yr 2019, after treatment application the overall herbaceous species identified in the experimental plots were grasses (64%), legumes (22%), and forbs (14%). In all treatment groups, legumes dominate in the first yr while grasses dominate in the second yr. Within treatment groups, dry matter yield (DMY) increment was recorded from the first yr to the second yr, by values ranging from 2.9% to 23.0%. The mean DMY in the desho + FYM + Desmodium uncinatum plots (8.4 t ha−1) was higher (P < 0.001) than controls (4.4 t ha−1). Natural pasture treated with Napier or desho in conjunction with either Desmodium or FYM and their combinations had a higher crude protein content (P < 0.001) than natural pasture alone despite the fact that in vitro organic matter digestibility was higher in desho grass when combined with desmodium or FYM treatments. Plots treated with Napier + FYM, Napier + Desmodium, and desho + Desmodium + FYM showed organic carbon levels that were significantly (P < 0.001) higher than the controls. Overall, desho + FYM + Desmodium produced the greatest improvement in grazing land productivity by maintaining soil fertility.

Integrated poultry waste management by co-digestion with perennial grass: Effects of mixing ratio, pretreatments, reaction temperature, and effluent recycle on biomethanation yield

This work aims to enhance the efficiency of integrated poultry waste management in bio-circular-green economy by maximizing the co-digestion of chicken manure and its digestate-grown biomass. In a series of batch assays, Napier grass (NG) was mixed with chicken manure (CM) at various proportions (100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100) to identify co-substrate synergism, followed by physiochemical conditioning (size reduction and ultrasonication) of NG before co-digestion. Results indicated that NG mix of at least 80% was required to gain a full methanation potential of the individual substrates; no synergistic ratio above unity was found. However, the combined effect of size reduction and sonication was found to markedly improve the co-substrate’s biodegradability by 88.7%. The findings were then used to run continuous co-digestion at various operating regimes. In optimal continuous co-digestion condition, NG particle size of 0.6–2.4 mm combined with sonication intensity at 1111 kJ/kgTS improved biomethanation yield as high as 106.3%. Sub-thermophilic digestion at 45 °C was shown to give a higher and more stable CH4 yield than at 55 °C. Finally, it was also found that recycling liquid effluent at 40% to replace freshwater in feed, although showed no significant difference in CH4 yield (α = 0.05), noticeably increased system buffer capacity. This optimized biodegradation regime could give co-digestion waste management a higher overall plant efficiency and economic return.