Peanut Straw Research Articles

Changes in the physicochemical characteristics of peanut straw biochar after freeze-thaw and dry-wet aging treatments of the biomass

Effects of aging after pyrolysis were tested relative to the physicochemical characteristics of peanut straw biochar. Biochar was prepared at pyrolysis temperatures of 350 °C, 500 °C, and 650 °C; then, it was freeze-thawed and dry-wet aged. The physicochemical characteristics of the fresh and aged biochar were analyzed. The results showed that the pyrolysis temperature, ambient temperature, and humidity affected the physicochemical characteristics of the biochar. With the increase of pyrolysis temperature, the yield and surface acidic functional groups of the fresh biochar decreased, whereas the ash content, C content, pH, specific surface area, and mesoporous volume of the fresh biochar increased. The aging treatment increased the acidic functional groups content in the biochar and reduced the aromatic functional groups content, which decreased the pH value of the biochar. The aging treatment increased the specific surface area and pore volume of the biochar, and the effect of freeze-thaw aging was greater than that of dry-wet aging. The aging treatment also destroyed the complete shape of the fresh biochar, and reduced its stability. After the aging treatment, the C content of the biochar decreased, whereas the O content increased, due to oxidation of the biochar.

Long-term manure application increases soil organic matter and aggregation, and alters microbial community structure and keystone taxa

Microbes play pivotal roles in soil organic matter (SOM) turnover: formation and decomposition. Organic fertilizers play crucial role for SOM accumulation, aggregate formation and influence microbial community composition and co-occurrence networks in microhabitats. Here, we investigated prokaryotic and fungal communities and their co-occurrence networks in four aggregate size classes in upland Ultisol following 27 years of mineral and/or organic fertilizer (rice straw, peanut straw, radish, or pig manure) application. Organic fertilizers and aggregate size classes have main and interactive effects on SOM content in aggregates (p < 0.001). Aggregate size classes accounted for most of the variance (43%) of SOM content, with more SOM accumulated in macroaggregates (>250 μm) than microaggregates (<250 μm). Increased aggregate size affected prokaryotic and fungal community structure by increasing Rhizobiales and decreasing Eurotiales. Solibacterales and Mortierellales were particularly abundant in small microaggregates (<53 μm) due to substrate preferences. Organic fertilizers regulate microbial community structure more than aggregate size, accounting for 41% and 29% of variance in prokaryotic and fungal communities, respectively. Pig manure exerted the strongest effect on SOM content and aggregation, and influenced microbial community structure more strongly than plant residues, primarily by increasing Bacillales, Gaiellales and Pezizales, and decreasing Thermogemmatisporales. This effect of pig manure was related with efficient increase of SOM content and pH. Co-occurrence network analysis revealed more positive or negative linear relationships among microbial groups in microaggregates than in macroaggregates, indicating stronger synergistic and antagonistic microbial interactions in microaggregates with fewer favorable niches (higher recalcitrant SOM and less labile SOM). Thermogemmatisporales was identified as the most influential keystone taxon (relative abundance ∼4.9%) in soil, and its abundance rapidly diminished with increasing SOM content in macro- and microaggregates. Thus, microbial community structure is dependent on aggregate size, and this should be considered during sampling. Overall, long-term pig manure amendment increased the SOM content and aggregation, altering prokaryotic and fungal community structure and keystone taxa.

Manure over crop residues increases soil organic matter but decreases microbial necromass relative contribution in upland Ultisols: Results of a 27-year field experiment

Organic fertilizers increase soil organic matter (SOM) stocks, but the underlying processes depend on the fertilizer type and remain largely unknown. To evaluate the predominant C stabilization mechanisms, upland Ultisols subjected to 27 years of mineral and organic fertilization were analyzed for SOM content, aggregate size classes, and amino sugar composition. The long-term field experiment had seven treatments: no fertilization (Control), mineral NPK fertilizers (NPK), NPK plus lime (NPK + Lime), NPK plus peanut straw (NPK + PeanutStraw), NPK plus rice straw (NPK + RiceStraw), NPK plus radish residue (NPK + RadishResidue), and NPK plus pig manure (NPK + PigManure). The 27-year application of mineral fertilizers (NPK and NPK + Lime), NPK + crop residues, and NPK + PigManure increased SOM content by 11.0–13.2%, 16.3–25.3%, and 44.3%, respectively, compared with the Control. The aliphaticity and recalcitrance indices based on 13C nuclear magnetic resonance spectra of organic fertilizers were higher for pig manure than for crop residues. Both indices were closely correlated with SOM content after 27 years, so higher proportions of recalcitrant C in manure facilitated SOM accumulation. NPK + PigManure increased the mass proportion of large macroaggregates 2.9-fold compared with the Control, and reduced the effective diffusion coefficient of oxygen in the soil. Consequently, NPK + PigManure limited the activity and abundance of aerobes and the accessibility of SOM to microorganisms, in turn facilitating SOM accumulation. The application of mineral fertilizers, NPK + crop residues, and NPK + PigManure increased microbial necromass to 2.85–3.03, 3.21–3.45, and 3.62 g C kg−1, respectively, from 2.63 g C kg−1 in the Control. Compared with crop residues, pig manure did not affect bacterial necromass but increased fungal necromass from 2.19 to 2.39 g C kg−1 to 2.58 g C kg−1, which might associate with increased SOM stability. However, the relative contribution of microbial necromass to SOM was lower under NPK + PigManure than under NPK + crop residues, since more added C was protected in the NPK + PigManure soil. Our results suggest that manure may contribute to SOM accumulation and stabilization in three ways: directly through the input of recalcitrant organic C, indirectly through the stabilization of aggregates and physical protection of C, and to a lesser extent through increasing fungal necromass.

Estimates on nitrogen uptake in the subsequent wheat by above-ground and root residue and rhizodeposition of using peanut labeled with 15N isotope on the North China Plain

Leguminous crops play a vital role in enhancing crop yield and improving soil fertility. Therefore, it can be used as an organic N source for improving soil fertility. The purpose of this study was to (i) quantify the amounts of N derived from rhizodeposition, root and above-ground biomass of peanut residue in comparison with wheat and (ii) estimate the effect of the residual N on the wheat-growing season in the subsequent year. The plants of peanut and wheat were stem fed with 15N urea using the cotton-wick method at the Wuqiao Station of China Agricultural University in 2014. The experiment consisted of four residue-returning strategies in a randomized complete-block design: (i) no return of crop residue (CR0); (ii) return of above-ground biomass of peanut crop (CR1); (iii) return of peanut root biomass (CR2); and (iv) return of all residue of the whole peanut plant (CR3). The 31.5 and 21% of the labeled 15N isotope were accumulated in the above-ground tissues (leaves and stems) of peanuts and wheat, respectively. N rhizodeposition of peanuts and wheat accounted for 14.91 and 3.61% of the BG15N, respectively. The 15N from the below-ground 15N-labeled of peanuts were supplied 11.3, 5.9, 13.5, and 6.1% of in the CR0, CR1, CR2, and CR3 treatments, respectively. Peanut straw contributes a significant proportion of N to the soil through the decomposition of plant residues and N rhizodeposition. With the current production level on the NCP, it is estimated that peanut straw can potentially replace 104 500 tons of synthetic N fertilizer per year. The inclusion of peanut in rotation with cereal can significantly reduce the use of N fertilizer and enhance the system sustainability.

Role of neutral extractives and inherent active minerals in pyrolysis of agricultural crop residues and bio-oil formations

The work reports a comparative study on the pyrolysis of five agricultural crop residues (peanut straw, cotton straw, sorghum stalk, corn stalk and reed) using a gas-sweeping fixed bed reactor. The study aims at clarifying the role played by the neutral extractives and inherent active minerals in the pyrolysis characteristics, product distributions and bio-oil compositions. Among five crop residues, reed showed the highest bio-oil yield but with the highest oxygen content and the lowest HHV (higher heat value), in relation to the least alkali and alkaline earth metals (AAEMs) in it. Peanut straw had a content of neutral extractives as high as 47.4%, which contributed to the formations of a significantly higher proportion of long chain aliphatic hydrocarbons and liquid nitrogenous compounds, distinct from four other crop residues. Peanut straw was also highly enriched with AAEMs, which was responsible for a strong catalytic activity for the selective deoxygenation of bio-oil. Neutral extractives in sorghum stalk and corn stalk formed some long chain fatty oxygenates and less nitrogenous compounds. The bio-oils derived from these two biomasses contained oxygenates as dominant compounds, however, they had a lower fraction of heavy constituents, lower oxygen contents, and higher HHVs than those of reed and cotton straw. This result was attributed to the catalyzed bio-oil deoxygenation by the relatively abundant AAEMs in sorghum stalk and corn stalk.

PM2.5 Associated PAHs and Inorganic Elements from Combustion of Biomass, Cable Wrapping, Domestic Waste, and Garbage for Power Generation

ABSTRACT PM2.5 fractions were collected by re-suspension of the ashes derived from the incineration processes of peanut straw (PS), wheat straw (WS), garbage-fired power plant (GFPP), domestic garbage for volume reduction (DG), and workshop of cable combustion for metal reclamation (WCC) for the analysis of 16 PAHs and 26 elements to obtain the information about their composition profiles, toxicity of PAHs, and exposure risks posed by heavy metals (HMs) and As. GFPP possessed the highest Ʃ16PAHs, while the lowest value occurred at DG. HMW-PAHs dominated in GFPP, while LMW-PAHs were predominant in PS and WS. BaP was the top PAH in GFPP and GFPP possessed the highest TEQ values based on the 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and BaP associated TEFs, and followed by WCC > DG > WS > PS. Except for DG vs. WCC, the PAH-, and HM vs. As-profiles between any 2 out of 5 sources were different based on higher coefficients of divergence than 0.3. The sum of 10 HMs and As (∑11IEs) dominated in WCC due to high contents of Cu, Zn, and Pb, and followed by GFPP > DG > WS > PS. The most enriched HMs were Sb, Cu, and Pb for WCC, Sn for GFPP, and Cd for both GFPP and DG. The integrated carcinogenic risks (CRs) for children posed by both dermal adsorption (Derm) and ingestion (ING) were higher than those for adults. The CRs for children from all the 5 sources exceeded the acceptable level of 1 × 10–4. The non-carcinogenic risks (NCRs) for children posed by both ING and DERM for 5 sources were much higher than those for adults. The NCRs for children posed by ING significantly exceeded 1, which were 63.8, 10.9, 4.11, 3.58, and 2.19 for WCC, GFPP, WS, DG, and PS.

Isothermal Adsorption Characteristics of Phenol from Straw Biochar

Peanut straw, sugarcane residue, cotton straw, was used as raw material to prepare the biochar adsorbent at 500°C, which were named PBC, SBC, and CBC. Phenol was subject to batch adsorption in aqueous medium by the prepared biochar. The results of adsorption experiments show that the kind of raw materials significantly affects its adsorption effect on phenol. The adsorption capacity of phenol from three kinds of biochar was PBC > SBC > CBC. In addition, the initial concentration of phenol in waste water, the temperature and time of adsorption can also affect the adsorption effect. The removal rates of phenol by three biochar decreased with increasing initial concentration of phenol. High temperature is beneficial to adsorption. When the initial concentration of phenol was 20 mg/L and the adsorption temperature was 45 °C, the removal rate of phenol was up to 99.7% after PBC adsorption. The reaction increased rapidly at the beginning of 60 min and reached the adsorption equilibrium after 180 min. The isothermal adsorption line for phenol conforms to the Langmuir mode and the Freundlich mode. The results provided a theoretical basis for the removal of organic pollutants such as phenol.

Humic substances from green waste compost: An effective washing agent for heavy metal (Cd, Ni) removal from contaminated sediments.

In this study, humic substances (HS) selected from 8 composting groups (peanut straw, sesame straw, corn straw and deciduous leaves, with or without grape marc) were used to remove Cd and Ni from artificially contaminated sediments. Sesame straw compost appeared to have the highest removal capacity for heavy metals through a series comparison on Cd removal efficiency, yield of HS and fulvic acids (FA), and seed germination index. The selected sesame HS was further used to wash two contaminated sediments of varying properties (a clay type for sediment 1 and a silty loam for sediment 2). Batch desorption experiments were conducted to determine the optimum HS concentration, equilibrium time, pH, solid-to-liquid ratio, and washing frequency. Under optimum conditions, a triple washing removed 74.16% of Cd and 42.91% of Ni from sediment 1, and 86.88% of Cd and 43.84% of Ni from sediment 2, respectively, whereas a commercial FA only achieved half of the efficiency. After washing, both sediments were identified with increased contents of total organic matter total nitrogen and phosphorus. Therefore, HS from the sesame straw compost is a cost-effective, efficient and environmental-friendly washing agent to remove heavy metals from contaminated sediments.

Long-term application of manure over plant residues mitigates acidification, builds soil organic carbon and shifts prokaryotic diversity in acidic Ultisols

Addition of organic materials is believed to be a feasible practice for mitigating Ultisols acidification and loss of soil organic carbon (SOC). However, how organic materials mitigate acidification, affect SOC content and aggregation and shift microbial community structure requires further investigation. In this study, we used high-throughput sequencing of microbial DNA to evaluate the relationships between soil properties, aggregation and prokaryotic communities in soil subjected to 27 years of inorganic and organic fertilization. The field experiment included seven treatments: no fertilization (control), inorganic NPK fertilizer (I), inorganic NPK fertilizer plus liming (CaCO3) (IL), and inorganic NPK fertilizer plus peanut straw (IPS), rice straw (IRS), radish (IR), or pig manure (IPM). Amendment with NPK fertilizer plus pig manure more effectively increased soil pH, SOC, total nitrogen (TN), available phosphorus (AP) and dissolved organic carbon (DOC) compared with NPK fertilizer plus crop residues. IPM also increased the mass proportion of large macroaggregates (>2000 μm) from 7.8% in the control to 30.6% while it reduced effective diffusion coefficient of oxygen (DCo) from 12.58 × 10−6 m2 s−1 in the control to 2.81 × 10−6 m2 s−1. Application of pig manure increased prokaryotic diversity and altered prokaryotic community structure, while crop residues did not. Soil pH was the predominant factor influencing prokaryotic community structure. Bacillales and Clostridiales accounted for 47.5% and 21.4%, respectively of the indicator species in the IPM and the relative abundances of them were increased, compared with the other treatments. Furthermore, the relative abundances of Bacillales and Clostridiales were correlated with SOC, TN, AP and DOC, and negatively with DCo in the soil. Overall, our results suggest that application of NPK fertilizer plus pig manure rather than crop residues enhanced soil pH, improved SOC content and aggregation, increased prokaryotic diversity and altered community structure of prokaryote after 27-year fertilization.

KECERNAAN NDF DAN ADF YANG MENDAPAT SUPLEMENTASI UREA MOLASSES MULTINUTRIENT BLOCK (UMMB) DARI BEBERAPA JENIS LIMBAH PERTANIAN DAN RUMPUT LAPANG PADA SAPI PERANAKAN ONGOLE (PO)

NDF AND ADF DIGESTIBILITY WHICH GET THE SUPPLEMENTED UREA MOLASSES MULTINUTRIENT BLOCK (UMMB) OF SOME CROP RESIDUES TYPE AND LOCAL GRASS ON ONGOLE CROSSBRED CATTLE. A research evaluating dry matter (DM) and organic matter (OM) digestibility of crops residues and local grass supplemented urea molasses multinutrient block (UMMB) on Ongole crossbred cattle (PO). Four male PO cattle, 12 – 18 months of age with ± 100 kg of body weight were used in this experiment. Latin Square Design 4 x 4 with 4 cows and 4 treatments was used. The treatments were : R1 : UMMB + local grass, R2: UMMB + Corn straw, R3: UMMB + Rice straw, and R4: UMMB + peanut straw. The results showed that there were significant effect (P&lt;0.01) of treatments on NDF and ADF digestibility. C1 showed that NDF and ADF digestibility of local grass (68.44% and 61.37%) were higher (P&lt;0.05) compared to crop residues (corn straw 65.25% and 58.59%, rice straw 62.63% dan 52.80%, and peanut straw 67.53% and 59.81%) respectively. C2 showed that NDF and ADF digestibility of legume straw was higher than grasses straw; and C3 showed that NDF and ADF digestibility of rice straw was lower than corn straw. The results have concluded that : 1. NDF and ADF digestibility of local grass were higher compared to crop residues. 2. NDF and ADF digestibility of legume straw (peanut straw) was higher than grasses straw (corn straw and ricce straw);3. NDF and ADF digestibility of corn straw was higher than peanut straw.Key words: NDF and ADF digestibility, crop residues, UMMB, ongole crossbred cattle

Long-term application of lime or pig manure rather than plant residues suppressed diazotroph abundance and diversity and altered community structure in an acidic Ultisol

Biological fixation of atmospheric dinitrogen (N2) is an important process that replenishes biologically available nitrogen (N) in soil and helps minimize the use of inorganic N fertilizer in agricultural ecosystems. Diazotrophs are key fixers of atmospheric N2 in a range of soil types, however, there is uncertainty about how they respond to long-term fertilization. Here, using the nifH gene as a molecular marker, we investigated the long-term effects of inorganic and organic fertilization on diazotroph abundance and community structure in an acidic Ultisol. The field experiment ran for 27 years and comprised seven treatments: no fertilization (control); inorganic NPK fertilizer (N); inorganic NPK fertilizer + lime (CaCO3) (NL); inorganic NPK fertilizer + peanut straw (NPS); inorganic NPK fertilizer + rice straw (NRS); inorganic NPK fertilizer + radish (NR); and inorganic NPK fertilizer + pig manure (NPM). Long-term application of fertilizer reduced the abundance and diversity of nifH gene compared with the control (P < 0.05), while lime and pig manure increased the inhibitory effects (P < 0.05). The abundance and diversity of nifH genes were negatively correlated with soil pH, indicating that increasing soil pH potentially affect N fixation ability in acidic Ultisols. Community structure of diazotrophs in the NPS, NRS, and NR treatments were similar and shared most operational taxonomic units (OTUs) with the N treatment, with only a minor difference to that of the control. Thus, there was no effect of plant residue types on diazotroph community structure. In contrast, the application of inorganic fertilizer + liming or pig manure altered the diazotroph community structure with shifts in the dominant genus, from Bradyrhizobium in the control to Azohydromonas in NL and Azospirillum in NPM. Soil pH was the key factor correlated with change in diazotroph community structure. Overall, our results suggested that regular use of lime or pig manure rather than different types of plant residue reduced the abundance and diversity and altered community structure of diazotrophs, that may potentially affect N fixation ability in acidic Ultisols.

Pengaruh Penggunaan Daun Pepaya Sebagai Bahan Pakan dan Lama Penghentiannya Terhadap Performan dan Kualitas Daging Kambing Bligon

Agricultural waste products used as livestock feed are rice straw, peanut straw, zea mays straw and others. Waste of pepaya’s estate can be used as feedstuff as well especially pepaya leaves. Small ruminants such as goats are able to adapt well with various available forages. Farmers in Borobudur District, Magelang Regency have fed their goats with pepaya leaves and according to them the goat can grow well, fat and healthy. However, there were information from consumers and goat slaughterers that the meat produced and its visceral organs especially liver were organoleptically unacceptable due to the bitter taste and the slightly greenish in colour. The experiment using 27 female bligon goat of about 6 month old with the average body weight of 13,9 ± 0,8 kg was carried out to find a good solution of the above problem. The goat were randomly divided into three group feeding treatments and fed with ration of R0 (control/without pepaya leaves consisting of 10% leaves of waru/&lt;em&gt;Hibiscus tiliacus&lt;/em&gt; leaves, 15% leaves of jackfruit/&lt;em&gt; Artocarpus heterophyllus &lt;/em&gt;and 75% native grass), R1 (25% pepaya leaves and 75% native grass), and R2 (50% pepaya leaves and 50% native grass). After 10 weeks the feeding trial was stopped and then all goats were fed with R0 ration (pepaya’s feed withdrawal) for two weeks. Meanwhile three goats from each group were taken for slaughter (first slaughtering at week 0 of pepaya’s feed withdrawal). The second and third slaughtering were caried out at week 1 and week 2of pepaya’s feeding withdrawal. The data collected were analyzed statistically using analysis of variance of completely randomized design (bligon goat performances, chemical composition and physical quality of meat) and analysis of non parametric for the sensorial characteristics of meat, any differences among the treatments were further-tested using Duncan test (DMRT). The results showed that the ration containing pepaya leaves significantly influenced the final body weight (P&amp;lt;0.05) and feed consumption (P&amp;lt;0.01) of bligon goats but not their average daily gains and carcass percentages. Chemical composition of the meat of bligon goat was significantly influenced by pepaya leaves (P&amp;lt;0.05). Fat content of bligon goat meat significantly increased as the level of pepaya leaves in the ration increased. On the other hand, the fat would decrease as the pepaya’s withdrawal commencing (P&amp;lt;0.05). Pepaya leaves significantly decreased pH and water holding capacity of the meat (P&amp;lt;0.05) but it did not increase the tenderness. Pepaya leaves significantly caused bitter taste in the meat and the liver of bligon goat (P&amp;lt;0.05). The bitter taste of the meat and liver would gradually decrease as the pepaya’s withdrawal commencing (P&amp;lt;0.05). The conclusion of the experiment was that pepaya leaves could be used as part of the bligon goat ration without affecting the performances of the animals, however, the pepaya’s feeding should be stopped as least two weeks before slaughtering to eliminate the bitter taste from the meat and liver of the bligon goat.

Nutrient Intake and Digestibility in Merino Sheep Fed Peanut Straw

This study aimed to compare nutrient intake and digestibility between male and female Merino fed peanut straw as sole feed. Four male and five female Merino sheep ages 10 to 12 month with average weight of 40 kg were used in this study. All animals were confined in individual metabolism cages and nylon nets were fitted bellow the cages for faecal collection. This experiment was done with 14 d adaptation period and 7 d collection period. Representative sample of feed, refusal feed, and faeces were analysed proximate including dry matter (DM), organic matter (OM), crude protein (CP), crude fibre (CF), ether extract (EE), and extract-free nitrogen (EFN). Data collected were used to calculate nutrient intake and digestibility. All nutrient intake in male Merino was higher (P<0.05) than female one, whereas digestibility of DM, CP, and CF in male Merino sheep were higher (P<0.05) than female sheep. It could be concluded male Merino sheep consumed feed more than female, but they had similar value of digestibility.

Peanut straw biochar increases the resistance of two Ultisols derived from different parent materials to acidification: A mechanism study

The mechanisms for increasing soil pH buffering capacity (pHBC) and soil resistance to acidification by peanut straw biochar were investigated by undertaking indoor incubation and simulated acidification experiments using two Ultisols derived from tertiary red sandstone and quaternary red earth. The biochar increased the pHBC and resistance of the two Ultisols to acidification. The addition of 3% biochar increased the pHBC of the two Ultisols by 76% and 25%, respectively. The increased resistance of the soils to acidification led to the inhibition to decrease in soil pH and the activation of soil Al during acidification. The protonation of carboxyl groups on the biochar surface was the main mechanism responsible for resisting acidification of the Ultisols when the pH was between 4.5 and 7.0. The higher soil pH (>6.0) after biochar application and the large number of carboxyl groups on the biochar surface were essential if biochar was to significantly increase the resistance of soils to acidification.

Performance comparison of different plant fiber/soybean protein adhesive composites

To compare the properties of different plant fiber/soybean protein adhesive composites, six types of plant fibers (rice straw, wheat straw, peanut straw, rice husk, wheat husk, and peanut shell) were selected as reinforced materials, and soybean protein adhesive was used as the adhesive. Six types of different bio-composites were prepared by the compression molding process. The Fourier transform infrared (FTIR) spectra, mechanical properties, moisture absorption, and thermal stability of the composites were measured. The tensile cross-section microstructure of the composites was examined. Results showed that the peanut straw/soybean protein adhesive composite contained more hydrophilic groups. The wheat fiber-based composites possessed more hydrogen bonds, leading to the best binding interface compatibility and mechanical properties. The wheat straw/soybean protein adhesive composite had the highest tensile strength, flexural strength, and impact strength, which were 337.7%, 638.6%, and 483.4%, compared to those of the rice husk/soybean protein adhesive composite, respectively. The peanut shell/soybean protein adhesive composite’s equilibrium moisture content was the lowest (8.70%). The rice husk/soybean protein adhesive composite had the highest equilibrium moisture content (14.23%), and the best thermal stability as the initial temperature of pyrolysis was 283.4 °C and the residual mass was 34.45%.

Influence of nitrogen fertilizer forms and crop straw biochars on soil exchange properties and maize growth on an acidic Ultisol

ABSTRACTEffects of repeated application of urea (UN) and calcium nitrate (CN) singly and together with crop straw biochars on soil acidity and maize growth were investigated with greenhouse pot experiments for two consecutive seasons. Canola straw biochar (CB), peanut straw biochar (PB) and wheat straw biochar (WB) were applied at 1% of dried soil weight in the first season. N fertilizers were applied at 200 mg N kg−1. In UN treatments, an initial rise in pH was subjected to proton consumption through urea hydrolysis, afterwards nitrification of NH4+ caused drastic reductions in pH as single UN had soil pH of 3.70, even lower than control (4.27) after the 2nd crop season. Post-harvest soil analyses indicated that soil pH, soil exchangeable acidity, NH4+, NO3− and total base cations showed highly significant variation under N and biochar types (P < 0.05). Articulated growth of plants under combined application with biochars was expressed by 22.7%, 22.5%, and 35.7% higher root and 25.6%, 23.8%, and 35.9% higher shoot biomass by CB, PB and WB combined with CN over UN, respectively. Therefore, CN combined with biochars is a better choice to correct soil acidity and improve maize growth than UN combined with biochars.

Efektivitas Penggunaan Daun Kembang Sepatu sebagai Agensia Defaunasi dalam Pakan Berkonsentrat Tinggi dengan Jenis Hijauan Berbeda Ditinjau dari Kecernaan Nutrienpada Kambing Kacang Jantan

&lt;p&gt;&lt;em&gt;Feeding high-concentrateration stimulates the protozoa to grow quickly, thus inhibits the growth of rumen bacteria,and leads to decrease in digestibility of nutrients, especially crude fiber. Defaunation is required to reduce the protozoa population in the rumen, for exampleby using China rose (Hibiscus rosa-sinensis) leafwhich containing saponins. This study investigated the effectiveness of China rose leaf as defaunation agent in high-concentrate feed with different forage based on nutrient digestibility in kacang goats. A total of16 male kacang goats with average body weight of 13.68 ± 1.55 kg was divided into 2 treatments i.e. P1: 40% peanut straw + 50% concentrate + 10% China roseleaf and P2: 40% king grass + 50% concentrate + 10% China rose leaf. The data obtained were analyzed by t-test. The results showed that the goats fed peanut straw generated higher (P&amp;lt;0.05) dry matter intake than the goats fed king grass (819.56 vs 678.65 gram/head/day). Furthermore, the dry matter digestibility in goats fed peanut straw was higher (P&amp;lt;0.01) than king grass (81.93 vs71.64%). The same results were observed for the digestibility of organic matter (82.96 vs74.35%) and crude fiber(78.12 vs 64.00%). It can be concluded that the use of China roseleaf in ration containing peanut strawwas more effective as defaunation agent as indicated by higher nutrient digestibility rather than in ration containing king grass.&lt;/em&gt;&lt;/p&gt;

Heating Process Characteristics and Kinetics of Biomass at Different Oxygen Concentrations

Abstract Mass transfer is very important for the combustion of biomass fuels, especially pellets. The oxygen diffusion, which results in a nonuniform distribution of oxygen in the pellets, should be considered in the modeling of pellet combustion. In this study, the effect of oxygen on thermal degradation of biomass is studied by thermogravimetric (TG) experiments and then a kinetic model considering oxygen effect is developed. The fuels investigated are spruce, sophora, wheat straw, and peanut straw. TG curves are taken under different oxygen concentrations, ranging from 0 to 20 %. Oxygen concentration has little effect on the devolatilization but is critical for the behavior of char combustion. Reaction mechanism is proposed based on the observation of decomposition at different reaction conditions. The kinetic model consists of three devolatilization reactions (for cellulose, hemicellulose, and lignin) and one char combustion reaction. In the devolatilization steps, char and gas are formed as products and oxygen is not involved in the reactions. A power law dependence of oxygen is assumed for the char combustion stage. The model parameters are fitted by the experimental TG data and good agreement is observed between the experimental and modeled data at various oxygen concentrations and for different biomass fuels. It is expected that the developed kinetic model could be applied for the modeling of pellets combustion considering oxygen diffusion process.

English

Moringa oleifera and Pleurotus ostreatus are widely used as food or food supplements. They are demonstrated to have many beneficial effects on nutritional status and human health. The aim of the present study was to evaluate the nutritional value of M. oleifera and P. ostreatus mixture in specific proportions. The mushroom species was cultivated at the Mushroom Biotechnology Laboratory and M. oleifera at the botanical garden of the University Cheikh Anta Diop de Dakar, Senegal. The compost of P. ostreatus culture was corn and straw peanut. Mixtures of different proportion powders of M. oleifera and P.ostreatus were used for investigations. Results showed that the product contain 35.08% crude proteins, 14.28% carbohydrates, 22.71% fat, 20.96% fibers and 6.98% of total ash. The energy was 401.79 kcal for 100 g of dry matter. Among minerals, potassium (1566.83 mg/100 g) are the most abundant mineral element followed by phosphorus (318.55 mg/100 g), calcium (284.33 mg/100 g) and magnesium (253.14 mg/100 g); the less abundant was copper with 0.53 mg/100 g. This study shows that the used proportion of M. oleifera leaves and P. ostreatus powders mixture could be a good source of minerals, proteins and carbohydrates. Key words: Moringa oleifera, Pleurotus ostreatus, dietary supplement.

Amelioration of an acidic ultisol by straw-derived biochars combined with dicyandiamide under application of urea.

The rapid increase in agricultural pollution demands judicious use of inputs and outputs for sustainable crop production. Crop straws were pyrolyzed under oxygen-limited conditions at 400°C for 2h to prepare peanut straw biochar (PB), canola straw biochar (CB), and wheat straw biochar (WB). Then, 300-g soils were incubated each with urea nitrogen (UN) and UN + biochars with or without dicyandiamide (DCD) for 60days. During the incubations, soil acidification induced by urea was somewhat inhibited by biochars, but nitrification of hydrolyzed NH4+ produced much more acidity than the neutralization potential of the biochars. In single UN (200mg/kg) treatment, soil pH decreased drastically and the final pH after incubation was lower than the control. Antagonistic to UN, all three biochars neutralized the soil acidity, which was consistent to their inherent alkalinity. DCD inhibited nitrification which was obvious throughout the incubations, as 30mg/kg DCD+200mg/kg UN combined with 1% PB, CB, and WB retained 0.94, 0.79, and 1.19units higher pH, respectively, and significantly reduced exchangeable acidity over the treatments without DCD (P<0.05). The treatments of UN + biochars with and without DCD had highly significant effects on soil pH, exchangeable Al3+, NH4+-N, (NO3-+NO2-)-N, and available P (P<0.05). Amplified NH4+-N retentions at higher rates of PB referred increased negatively charged sites for nutrient adsorptions. Applied UN transformations varied among different treatments, and the maximum amounts of total mineral N recovered were 218.3, 218.5, and 223.8mg/kg in the presence of DCD by PB, CB, and WB, compared to 198.2, 201.6, and 205.2mg/kg, respectively, in no DCD treatments. Urea induced severe soil acidification and even lowered the ameliorative effects of applied biochars. Thus, ammonium-based fertilizers must include nitrification inhibitor (DCD) and, if used in combination with biochars will offer a suitable choice to reduce the acidity, improve base saturation and fertility of soil for sustainable agriculture.