Grass Growth Research Articles

Enhanced efficiency nitrogen formulations for bermudagrass–white clover pastures

AbstractNitrogen fertilizer use is generally restricted in bermudagrass [Cynodon dactylon (L.) Pers.]–white clover (Trifolium repens L.) forage systems because it stimulates grass growth and increases competition with the clover, compromising forage nutritive value and prospective forage accumulation. Enhanced efficiency fertilizer nitrogen (N) products hold potential to improve white clover persistence in bermudagrass–clover pastures while providing supplemental N required by the grass. This study evaluated the effect of different enhanced efficiency N formulations (Environmentally Smart Nitrogen [ESN]; methylene urea; SuperU; and 75% ESN, 25% urea blend) and untreated urea on forage accumulation, nutritive value, and legume persistence in a ‘Wrangler’ bermudagrass and ‘Durana’ white clover mixture. Nitrogen was applied at four rates (0, 112, 224, and 448 kg N ha−1) in two equal applications each year. By the second year, white clover stands were lesser at the greatest N rates. All enhanced efficiency N sources maintained white clover similar to the unfertilized grass–clover control, but only ESN improved white clover persistence over urea. Total season forage accumulation increased linearly with increasing N rates within all three growing seasons, but dry weather conditions in the last 2 yr resulted in less forage accumulation. Nutritive value decreased with maturity throughout the growing season, but ESN maintained clover in the pasture resulted in overall less fiber components and greater digestibility. Although there was no effect of N source on forage accumulation, the ability of ESN to maintain clover could make it a viable option for fertilization in bermudagrass–white clover mixtures.

Man-made impact on green areas in buffer zones along Moscow highways

Turf grass in a metropolis is not only responsible for improving environmental conditions. It contributes to a comfortable visual urban environment. The state of lawn grasses investigated in the buffer zones along highways in the city of Moscow signified their unsatisfactory state, which can be attributed both to incorrect selection of turf grass blending ratios and imperfection of technological operations for lawn care. High concentrations of heavy metals were found to be present in the soil and biomass of lawn grasses, which requires activities and compliance with the regulations to ensure bioremediation of territories. The use of anti-ice reagents in winter leads to a changing acidity of the soil along the transport routes, which additionally affects the initial growth of lawn grasses in spring after snow melt. To promote sustainable ground cover in the city, it is recommended to use resistant perennial plants.

Whither the science in wildlife management?

Whither the science in wildlife management?

Identification of grass growth conditions based on sheep grazing acoustic signals

The acoustic signals of sheep grazing carry a wealth of information. To date, the information on grazing behavior and intake in acoustic signals has been thoroughly explored and utilized. However, information on grass growth conditions (grass conditions) has received little attention from scholars, although it is crucial for making rotational grazing decisions. This study tries to efficiently mine and process the grass condition information in acoustic signals to obtain a high-performing recognition model. First, the acoustic signals collected under three grass conditions were divided into many segment samples. Second, six types of formal samples were constructed from every segment sample. Last, the log-Mel features of the six formal samples were separately fed into a convolutional neural network (CNN) model or a recurrent neural network (RNN) model to identify the grass conditions. Before the log-Mel features were fed into the model, two methods of unifying the sample length and multiple specified lengths were used to pre-process the formal samples. The results showed that the combination of the fixed chewing and biting connection (FCB) sample and the CNN model performed the best, with an accuracy of 90.24%. The method of filling or truncating the sample’s waveform tended to be better than scaling the sample’s log-Mel feature when the specified length was longer than 8 s. The different specified lengths had an essential effect on the accuracy of the model with the filling method. The application of this study could provide a data reference for constructing a more rational rotational grazing strategy.

Bioherbicidal Activity and Metabolic Profiling of Potent Allelopathic Plant Fractions Against Major Weeds of Wheat-Way Forward to Lower the Risk of Synthetic Herbicides.

The productivity of major field crops is highly compromised due to weed infestation. Inefficient weed management practices and undue and excessive use of chemical herbicides have drastically contaminated the environment and human health, in addition to resistance development in weed species. Therefore, utilization of allelopathic plants to explore phytochemicals as potent organic alternatives to such chemical herbicides has become indispensable. The current study evaluates the comparative bio-herbicidal potential of methanolic extracts of castor (Ricinus communis), artemisia (Artemisia santolinifolia), wheat (Triticum aestivum), and sorghum (Sorghum bicolor) to suppress growth of major weeds, i.e., wild mustard (Sinapis arvensis), Italian ryegrass (Lolium multiflorum), and carrot grass (Parthenium hysterophorus). The results demonstrated a concentration-dependent effect on weeds’ growth. Overall, in vitro seed germination was reduced from 60 to 100% in response to 5% (w/v) extract concentration. Significant reduction in radicle length, hypocotyl length, and fresh biomass of the weeds was also observed. A strong inhibitory effect was seen in in vivo pot experiments, revealing that application of 10–20% methanolic extracts induced permanent wilting and substantial reduction in the chlorophyll content of weeds along with 20–80% increase in oxidative stress. Artemisia showed the most significant allelopathic effect, on account of highest phenolic and flavonoid contents, followed by castor, wheat, and sorghum, against S. arvensis, L. multiflorum, and P. hysterophorus, respectively. Phytochemical analysis, through high-performance liquid chromatography (HPLC), also exhibited a correlation between extract’s phytotoxicity and their antioxidant potential due to their major constituents (rutin, quercetin, catechin, gallic acid, vanillic acid, syringic acid, ferulic acid, p-hydroxy benzoic acid, p-coumaric acid, and sinapic acid), among the total of 13 identified in methanolic fractions. Comprehensive profiling of allelochemicals with liquid chromatography–mass spectrometry (LC-MS) determined 120, 113, 90, and 50 derivates of phenolic acids, flavonoids, and alkaloids, reported for the first time through this study, demonstrating significant allelopathic potential of the targeted plant fractions, which can be explored further to develop a sustainable bio-herbicidal formulation.

Understanding Grass Invasion, Fire Severity, and Acacia koa Regeneration for Forest Restoration in Hawaiʻi Volcanoes National Park

With invasive grasses increasing wildfire occurrence worldwide, a better understanding of the relationships between native plants, fire, and invasive grass is needed to help restoration plans facilitate ecosystem resilience. Invasive grasses are particularly problematic for altering fire regimes in the tropics, yet in Hawaiʻi, restoration sites are often planted with monocultures of the native tree Acacia koa, which can promote grass growth via nitrogen fixation. This, combined with the difficulty of estimating pre-fire grass cover under thick canopies, complicates attempts to restore Hawaiian ecosystems. We studied the 2018 Keauhou Ranch Fire in Hawaiʻi to investigate three questions: (1) at what level of precision can pre-fire grass cover be accurately estimated from oblique aerial photos? (2) how are post-fire A. koa regeneration densities affected by fire severity? and (3) how are post-fire A. koa regeneration densities affected by pre-fire grass cover and its interaction with fire severity? We collected burn severity and post-fire regeneration data from 30 transects stratified across mid-elevation woodland, montane woodland, and montane shrubland communities. We evaluated visual estimates of pre-fire grass cover from oblique aerial imagery with quantitative in situ data from 60 unburned transects of the same cover types. Pre-fire estimates of grass cover categories were 67% accurate in montane woodland (n = 9) and 100% accurate in montane shrubland (n = 11), but only 20% accurate in mid-elevation woodland (n = 10). In montane woodlands with low pre-fire tree densities, A. koa regeneration densities were higher with increased fire severity, but this trend reversed when pre-fire tree densities were high. We detected no effect of pre-fire grass cover, nor its interaction with fire severity, on A. koa regeneration density. This indicates that restoration through the planting of A. koa may be successful in promoting fire-resilient A. koa forest, although there are potential issues to consider regarding the effects that A. koa’s grass promotion may have on other species within the ecosystem.

The development of equations to predict live-weight from linear body measurements of pasture-based Holstein-Friesian and Jersey dairy heifers

Monitoring the live-weight of dairy heifers and thus meeting weight-for-age targets is regarded as one of the most important aspects of a heifer rearing enterprise as it optimizes future production. This is particularly important in pasture-based heifer rearing systems where growth is non-linear due to seasonal variation in grass growth and quality. Data were collected throughout the rearing period to estimate the live-weight of pasture-based Holstein-Friesian (n = 130) and Jersey (n = 57) dairy heifers using linear body measurements. Live-weight was regressed on heart girth, body volume and a polynomial of body length, heart girth, and withers height; all equations were validated within-herd. All three equations were accurate predictors of live-weight for pasture-based dairy heifers (R² > 0.92 and RMSE < 19.1 kg), therefore, in the absence of weighing scales, live-weight can be successfully predicted using linear body measurements. The equation which utilizes body volume of the heifer is proposed as the most suitable predictor of live-weight.

Grass modelling in data-limited areas by incorporating MODIS data products

• MODIS data products are incorporated into data assimilations of grass modelling. • Multiple scenarios of data availability are assumed for data-limited areas. • Different methods of data assimilation are compared based on data usage. Process-based grass models (PBGMs) are widely used for predicting grass growth under potential climate change and different management practices. However, accurate predictions using PBGMs heavily rely on field observations for data assimilation. In data-limited areas, performing robust and reliable estimates of grass growth remains a challenge. In this paper, we incorporated satellite-based MODIS data products, including leaf area index, gross primary production and evapotranspiration, as an additional supplement to field observations. Popular data assimilation methods, including Bayesian calibration and the updating method ensemble Kalman filter, were applied to assimilate satellite derived information into the BASic GRAssland model (BASGRA). A range of different combinations of data assimilating methods and data availability were tested across four grassland sites in Norway, Finland and Canada to assess the corresponding accuracy and make recommendations regarding suitable approaches to incorporate MODIS data. The results demonstrated that optimizing the model parameters that are specific for grass species and cultivar should be targeted prior to updating model state variables. The MODIS derived data products were capable of constraining model’s simulations on phenological development and biomass accumulation by parameter optimization with its performance exceeding model outputs driven by default parameters. By integrating even a small number of field measurements into the parameter calibration, the model’s predictive accuracy was further improved - especially at sites with obvious biases in the input MODIS data. Overall, this comparative study has provided flexible solutions with the potential to strengthen the capacity of PBGMs for grass growth estimation in practical applications.

Efficiency of Biostimulants for Alleviating Shade Effects on Forage Grass

Shade is considered an abiotic stress factor which reduce the primary metabolism and restricts normal growth in forage grass in integrated systems. Biostimulants are beneficial in promoting growth and protecting plants against environmental stresses. This is the first study that links biostimulants and the primary metabolism of plants grown under contrasting light intensities. We investigated how the use of biostimulants modifies the primary metabolism, reducing the deleterious effects of shading in the development of tropical forage grass Brachiaria brizantha cv. BRS Piatã. The association of Pseudomonas fluorescens and Burkholderia pyrrocinia, inoculated by soil drench, were used as biostimulants. We measured leaf anatomy, plant growth, and biochemical parameters. The use of biostimulants increased the shade tolerance on B. brizantha by modifying leaf structure, increasing the chlorophyll content, and inducing the production of osmoregulants, such as carbohydrates and proteins. In turn, increasing the accumulation of primary metabolites, promoted root development, plant height, and leaf area, resulting in more vigorous plants with greater biomass production. These results suggested that forage grass can be protected from inhibitory effects of the shade stress by the biostimulants, and this would improve its survival and growth in integrated crop-livestock-forestry systems.

The herbicide cycloxydim is an effective alternative to propyzamide or glyphosate for the control of the forest grass weeds Molinia caerulea, Calamagrostis epigejos, Deschampsia flexuosa and Holcus lanatus

Abstract We tested the efficacy of a range of herbicides to see if they might be potential substitutes for the use of propyzamide or glyphosate to control grass weed species that, if left unchecked, often outcompete recently planted trees in UK forests. Applications of 0.45kg a.i. ha−1 cycloxydim in late April–early May gave good control of wood small reed (Calamagrostis epigejos (L.) Roth), Yorkshire fog (Holcus lanatus L.), and wavy hair grass (Deschampsia flexuosa (L.) Trin.)) for at least 12 weeks after application. When coupled with a sequential application of 0.15kg a.i. ha−1 propaquizafop made 5 weeks later, purple moor grass (Molinia caerulea (L.) Moench) was controlled for at least 21 weeks. Sequential applications of 0.45 kg a.i. ha−1 cycloxydim in October, then 0.45 kg a.i. ha−1 cycloxydim in late April, was the most effective treatment for minimizing competition from purple moor grass, wood small reed or wavy hair grass and equally effective as propyzamide on Yorkshire fog. The herbicides carbetamide, clethodim, clodinafop-propargyl and fenoxaprop-p-ethyl were not as effective as cycloxydim. We conclude that cycloxydim is effective on a broader range of grass weeds than previously thought. Cycloxydim and propaquizafop are both highly selective and unlike the broad-spectrum herbicide glyphosate will not harm young trees, even if they are oversprayed when in active growth. If applied at the correct time of year, cycloxydim is likely to be as effective as glyphosate on most grasses, and for wood small reed, purple moor grass and wavy hair grass considerably more effective than propyzamide. A sequential application of cycloxydim or possibly propaquizafop in the autumn, followed by a second spray in late April of the following spring, is likely to be the most effective means of maximizing tree growth and survival in grass dominated new planting or restock sites in UK forests.

Grass Growth and N2O Emissions From Soil After Application of Jellyfish in Coastal Areas

The supply of nutrients for agricultural production faces enormous challenges as food security and sustainability goals have to be ensured. Processing of marine biomass has high potential to provide nutrients for agricultural purposes in coastal areas. One underexplored resource are jellyfish, which occur as blooms and by-catch of the fishing industry. In this context, a pot experiment investigated the effects of jellyfish as a fertilizer on biomass accumulation of annual ryegrass (Lolium multiflorum), and its effect on the important greenhouse gas N2O as a sustainability indicator of novel fertilizers. Dried and ground jellyfish was applied [3 species: Aurelia aurita (AA), Cyanea capillata (CC), Periphylla periphylla (PP)] and compared with an unfertilized and a mineral fertilized (calcium-ammonium-nitrate, CAN) treatment. Dried jellyfish and CAN were applied at equal N rates of 5 g N per m2. The N2O-fluxes from soil were measured over 56 days after fertilizer application. Grass dry matter yields, when using CC and PP treatments, were not significantly different to the CAN treatment (p &amp;gt; 0.05). After reducing its salinity, AA also showed no differences to CAN on plant growth and the lowest coefficient of variation for dry matter yield as an indicator for yield stability. Accumulated N2O-emissions were lowest in the control and were 3-times higher in AA and CC compared to CAN (p &amp;lt; 0.05). If salinity levels are moderate, jellyfish application to soil can compete with artificial mineral fertilizers in terms of N-supply for above- and belowground yield response, regardless of jellyfish species used. However, elevated N2O-emissions are likely to affect its suitability for large-scale application. Nevertheless, if energy-efficient methods of drying and desalination of jellyfish can be developed, in coastal areas dried jellyfish is a valuable fertilizer in coastal areas, particularly in situations where nutrient supplies for agriculture are limited.

The feedback regulation of carbohydrates intake on food intake and appetite in grass carp (Ctenopharyngodon idella)

Improving carbohydrate utilization can contribute to sustainability of aquaculture. In order to explore the feedback mechanism of glucose homeostasis in fish, one control diet (25% carbohydrate and 40% protein), one relatively high carbohydrate diet named HG (42% carbohydrate and 40% protein), and one high dietary carbohydrate coupled with relatively low protein diet named HGP (42% carbohydrate and 25% protein) were fed to grass carp for 40days. After the feeding trial, HG group impeded the food intake and growth performance of fish compared with the other two groups. Meanwhile, the serum glucose and insulin level were both significantly elevated under the condition of high carbohydrates intake when compared HG with control group. However, although no significant difference was observed in peripheral glucose or insulin between HG and HGP groups, fish fed with HGP diet increased growth performance and food intake compared with the HG group. Gene expression data indicated that fish selectively regulated the expressions of the cerebral anorexigenic genes (cart and pomc) to adapt to the HG and HGP intake. Therefore, the HGP diet with high carbohydrate and low protein was more suitable for grass carp feeding and growth when compared with the other two diets, possibly because the diet composition was closer to the natural food of this fish. In addition, the serum leptin level was highly consistent with changes in food intake and anorexigenic gene expressions when comparing the three experimental diets, indicating that leptin might be the key to mediate the feedback regulation of carbohydrates intake on food intake and appetite in fish.

Short-term impact of fire on the total soil microbial and nitrifier communities in a wet savanna.

Savannas are characterized by the coexistence of grasses and trees. Fires are critical for their coexistence, because they decrease the survival of tree seedlings and saplings and their recruitment to the adult stage. In some humid savannas, perennial grasses inhibit nitrification and trees stimulate nitrification, which likely favors coexistence between trees and grasses. However, fires may influence plant capacity to control nitrogen cycling, which could subsequently influence tree–grass coexistence and savanna nitrogen budget. Therefore, we sampled soil in a humid savanna of Ivory Coast under the dominant nitrification‐inhibiting grass species and the dominant nitrification‐stimulating tree species and under bare soil before and after (i.e., 5 days) fire during the long dry season. We quantified the total microbial and nitrifier abundances and transcriptional activities and the nitrification enzyme activity. Fire decreased soil water content, probably by increasing evaporation and, maybe, by triggering the growth of grasses, and increased soil ammonium availability likely due to ash deposition and increased mineralization. Fire did not impact the total archaeal, bacterial, or fungal abundances, or that of the nitrifiers. Fire did not impact archaeal transcriptional activity and increased bacterial and fungal total transcriptional activities. In contrast, fire decreased the archaeal nitrifier transcriptional activities and the nitrification enzymatic activity, likely due to the often reported resumption of the growth of nitrification‐inhibiting grasses quickly after the fire (and the subsequent increase in root exudation). These results pave the way for a better understanding of the short‐term effects of fire on nitrogen cycling and tree–grass competition for nitrogen.

Effect of sewage sludge application on growth and photosynthetic pigments in vetiver grass (&lt;em&gt;Vetiveria zizanioides&lt;/em&gt; L. Nash)

The study was conducted to evaluate the effect of sewage sludge application on growth and photosynthetic pigments in vetiver grass. Vetiver plants were grown in poly-ethylene U-V stabilized grow bags (24 X 24 X 40) for a period of three months (90 days), where the soil treated with different sewage sludge concentrations (0, 25, 50 and 75%). Physico-chemical characterization of sewage sludge showed that it was slightly acidic with significant concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn), nutrients and mineral ions. Results showed that there were no apparent symptoms of toxicity on the morphology (leaf color, plant height and number of leaves) of the sludge amended vetiver plants. It has been observed that 25% sludge concentration has a favorable effect on the growth and photosynthetic pigments of plants. But at 50 and 75% sludge concentration, photosynthetic pigments such as chlorophylls and Pheophytin content showed a gradual decline with increase in sludge concentration while the carotenoid content was increased gradually. Even though compared to control plants sludge amendment increased the total wet biomass production in all the experimental plants with a gradual increase with increase in sludge concentration. This study proves that use of sewage sludge as an amendment will improve the growth and biomass production in vetiver plants up to 25% of the total soil. But even at this concentration carotenoid content was high and it may be due to defense mechanisms induced in response to heavy metal stress. The study, therefore, suggests that even though the sewage sludge is highly enriched with various nutrients, considering the heavy metal content, the fertilizer application of sewage sludge is dangerous, because the risk of environmental contamination is very high. The study pointed out that the vetiver plants growing in sludge amended area have potentially developed the defense strategy to combat against heavy metal toxicity. Therefore, the highly tolerant vetiver plants (Vetiveria zizanioides, L. Nash) may be used for phytoremediation purposes.

Effect of Different NPK Levels on Fodder Production of Sudan Grass (Sorghum bicolor var. Sudanese)

A field experiment was conducted at R.G.S.C, Banaras Hindu University, Mirzapur, Uttar Pradesh, India during 2016 in kharif season (Sep.-Oct.) The aim was to evaluate the effect of different nitrogen, phosphorus and potassium level on fodder production of sudan grass (Sorghum bicolor var. Sudanese) for optimization of growth and yield, crude protein content and economics of sudan grass. The experimental was laid out in split plot design with four levels of nitrogen i.e. 60 kg N ha1, 80 kg N ha1, 100 kg N ha1 and 120 kg N ha-1 as main plot treatments and in the sub-plot three levels of phosphorus and potassium i.e. 30 kg P2O5+20 kg K2O ha-1, 40 kg P2O5+25 kg K2O ha-1 and 50 kg P2O5+30 kg K2O ha-1) were taken. The research findings revealed that application of nitrogen @ 120 kg ha-1 resulted maximum growth characters i.e. plant height (191.25 cm), number of leaf (8.02 plant-1), fresh weight (124.47 g plant-1), dry weight (21.10 g plant-1) and green fodder production (11455 kg ha-1), and as well as recorded maximum crude protein of sudan grass. The higher net return (` 7920.32 ha1) was also recorded with nitrogen @ 120 kg ha-1 and in case of levels of phosphorus and potassium the application of 50 kg P2O5+30 kg K2O ha-1 enhanced the growth, yield, quality and economics of sudan grass.

Levels of acid detergent insoluble protein in grasses and feeds made from them

The purpose of this research is to assess the level of thermal damage by determining the content of acid detergent insoluble crude protein (ADICP) in perennial cereal forage grasses Bromus inermis, Festuca pratensis, Phleum, depending on the phase of their vegetation (at the beginning of shooting, during the earing and flowering phases), as well as in silage and haylage prepared from them during the same phases. Samples for analyzes were dried at the temperature of 60-65 °C. Nitrogen of ADICP was determined in the residue of ADF (acid detergent fiber) obtained by filtering a solution of acid detergent through a paper filter. With the growth of grasses, an increase in the content of ADF in them was observed, followed by an increase in ADICP in Phleum and especially in Festuca pratensis which was characterized by higher rates of ADF accumulation. In Bromus inermis, the increase in ADF did not lead to an increase in the concentration of ADICP in the grass due to a decrease of its portion in ADF. The content of ADICP in green grass ranged from 0.85 to 1.58 % in dry matter, ADF ‒ from 27.0 to 45.8 %, no correlation was found between them. Conservation of grasses in all phases of their growth caused an increase in the content of ADF compared to the original grass, but the mass fraction of ADICP in the dry matter of silage and haylage was not higher than in the original grass, due to a lower mass fraction of ADICP in the ADF compared to grasses. In this regard, it is noted that if the technology of harvesting silage and haylage is observed, there is no increase in the level of thermal damage to these feeds. In this regard, it is noted, that when the preparation of silage and haylage is carried out according to the required technology, there is no increase in the level of thermal damage to these feeds. There is close correlation between the percentage of ADICP in CP (crude protein) and the contents of CP. The correlation coefficients were -0.83; -0.88 and -0.92 for grasses, silage and haylage, respectively. The lowest percentage of ADICP in CP was observed in the early phases of grass growth. In this regard, there is a need to harvest them in earlier growth phases, since the content of CP decreases with growth and the proportion of indigestible protein in it increases. If there are organoleptic signs of thermal damage to feeds given in the article, it is recommended to make an amendment to CP content on the basis of the result of the analysis for the content of ADICP.

Natural fire does not affect the structure and beta diversity of plant-pollinator networks, but diminishes floral-visitor specialization in Cerrado

Fire acts as an ecological filter determining species diversity and composition of communities. In tropical savannas in Central Brazil, natural fire happens through lightning, but anthropogenic fire is also common, either controlled fire prescribed for management of vegetation and to promote grass growth or accidental and intentional fires related to deforestation and land use changes. Frequent fire events can have a negative effect on biodiversity by causing deaths of susceptible organisms, as well as through the homogenization of vegetation. Besides the composition of plant and animal species, fire also modifies biotic interactions, such as pollination, which impact ecosystem functioning. Here, we evaluated how time since the last fire event (hereafter postfire time interval) affects the structure, beta diversity of interactions and specialization of plants and floral visitors in a naturally burned Cerrado area. Postfire time interval had no effect on the structure of interaction networks and community diversity metrics, including beta-diversity of interactions. We did, however, find a positive relationship between flower abundance and postfire time intervals, and a negative effect of postfire time intervals on floral visitor species-level specialization. Thus, the negative effect of postfire time intervals on floral visitor specialization may be explained by the lower resource availability in areas recently burnt. The lack of strong and consistent effect of time interval since the last fire on plant-pollinator interactions from the Cerrado probably results from the resilience of these interactions to natural fires, which is a common element in this ecosystem. Increased frequency of more intense anthropogenic fires, however, may have stronger effects on biodiversity, and deserves further investigation in this biodiversity hotspot.

Independent effects of drought and shade on growth, biomass allocation and leaf morphology of a flammable perennial grass Tetrarrhena juncea R.Br

Independent effects of drought and shade on growth, biomass allocation and leaf morphology of a flammable perennial grass Tetrarrhena juncea R.Br

Improving the Properties of Degraded Soils from Industrial Areas by Using Livestock Waste with Calcium Peroxide as a Green Oxidizer.

Over the past years, the treatment and use of livestock waste has posed a significant problem in environmental engineering. This paper outlines a new approach to application of calcium peroxide (CaO2) as a green oxidizer and microbiocidal agent in the treatment of poultry manure. It also presents the application of pretreated waste in improvement of degraded soils in industrial areas. The CCD (Central Composite Design) and RSM (Response Surface Methodology) were employed for optimizing the process parameters (CaO2 concentration 1.6–8.4 wt %, temperature 5.2–38.8 °C and contact time 7–209 h). The analysis of variance (ANOVA) was used to analyze the experimental results, which indicated good fit of the approximated to the experimental data (R2 = 0.8901, R2adj = 0.8168). The amendment of CaO2 in optimal conditions (8 wt % of CaO2, temperature 22 °C and contact time 108 h) caused a decrease in bacteria Escherichia coli (E. coli) in poultry manure from 8.7 log10 CFU/g to the acceptable level of 3 log10 CFU/g. The application of pretreated livestock waste on degraded soils and the studies on germination and growth of grass seed mixture (Lollum perenne—Naki, Lollum perenne—Grilla, Poa pratensis—Oxford, Festuca rubbra—Relevant, Festuca rubbra—Adio and Festuca trachypylla—Fornito) showed that a dose of 0.08 g of CaO2 per 1 gram of poultry manure induced higher yield of grass plants. The calculated indicators for growth of roots (GFR) and shoots (GFS) in soils treated with poultry manure were 10–20% lower compared to soils with amended CaO2. The evidence from this study suggests that CaO2 could be used as an environmentally friendly oxidizer and microbiocidal agent for livestock waste.

A Trojan horse approach for white mold biocontrol: Paraconiothyrium endophytes promotes grass growth and inhibits Sclerotinia sclerotiorum

Endophytic Paraconiothyrium strains associated with Brachiaria spp. and Panicum maximum were screened in vitro and in vivo for antagonism against Sclerotinia sclerotiorum and grass growth promotion. Based on multilocus phylogenetic analyses, three Paraconiothyrium estuarinum strains and two Paraconiothyrium cyclothyrioides strains were identified. In vitro, P. estuarinum strain CML 3699 was the most efficient in S. sclerotiorum mycelial growth inhibition. Volatile organic compounds (VOCs) produced by Paraconiothyrium strains reduced the sclerotia number, sclerotia weight and apothecia number in comparison to the control. The VOCs of P. cyclothyrioides strain CML 3698 promoted higher inhibitory effects on apothecium production. Paraconiothyrium estuarinum CML 3695, when inoculated into Brachiaria ruziziensis seeds, promoted increased biomass in comparison to those in non-inoculated seeds. All strains were sensitive to higher glyphosate doses, which reduced their mycelial development. However, when the mycelia of the endophytic fungi were removed and transferred to new PDA medium, the fungi recovered growth. After desiccation of Paraconiothyrium-inoculated B. ruziziensis with glyphosate, Paraconiothyrium strains recovered the ability to colonize the sclerotia of S. sclerotiorum and reduced carpogenic germination via a Trojan-horse-like mode of action. Considering that grass can be deployed by farmers as a physical barrier to S. sclerotiorum ascospore release, the growth promotion and parasitism of sclerotia exerted by Paraconiothyrium strains towards B. ruziziensis reinforce this disease control strategy.