Investigating potential hydrological ecosystem services in urban gardens through soil amendment experiments and hydrologic models

Among the ecosystem services provided by urban greenspace are the retention and infiltration of stormwater, which decreases urban flooding, and enhanced evapotranspiration, which helps mitigate urban heat island effects. Some types of urban greenspace, such as rain gardens and green roofs, are intentionally designed to enhance these hydrologic functions. Urban gardens, while primarily designed for food production and aesthetic benefits, may have similar hydrologic function, due to high levels of soil organic matter that promote infiltration and water holding capacity. We quantified leachate and soil moisture from experimental urban garden plots receiving various soil amendments (high and low levels of manure and municipal compost, synthetic fertilizer, and no inputs) over three years. Soil moisture varied across treatments, with highest mean levels observed in plots receiving manure compost, and lowest in plots receiving synthetic fertilizer. Soil amendment treatments explained little of the variation in weekly leachate volume, but among treatments, high municipal compost and synthetic fertilizer had lowest leachate volumes, and high and low manure compost had slightly higher mean leachate volumes. We used these data to parameterize a simple mass balance hydrologic model, focusing on high input municipal compost and no compost garden plots, as well as reference turfgrass plots. We ran the model for three growing seasons under ambient precipitation and three elevated precipitation scenarios. Garden plots received 12–16% greater total water inputs compared to turfgrass plots because of irrigation, but leachate totals were 20–30% lower for garden plots across climate scenarios, due to elevated evapotranspiration, which was 50–60% higher in garden plots. Within each climate scenario, difference between garden plots which received high levels of municipal compost and garden plots which received no additional compost were small relative to differences between garden plots and turfgrass. Taken together, these results indicate that garden soil amendments can influence water retention, and the high-water retention, infiltration, and evapotranspiration potential of garden soils relative to turfgrass indicates that hydrologic ecosystem services may be an underappreciated benefit of urban gardens.

Vegetative Growth of Sweet Corn (Zea mays L. Saccharata) Due to Difference Doses of Horse Manure Compost and NPK Fertilizer

Sweet corn has a sturdy and strong stem growth and is very suitable for cultivation in tropical climates. Research on the effect of horse manure compost combined with NPK fertilizer on the growth of sweet corn has been done with the aim of obtaining information: (1) the effect of different doses of horse manure compost on the growth of sweet corn, (2) the effect of different doses of NPK fertilizer on the growth of sweet corn, (3) The interaction effect of horse manure compost and NPK fertilizer on sweet corn vegetative growth. The application of NPK fertilizer was carried out with 4 treatment doses while the application of horse manure compost was carried out with 5 treatment doses. In this study, information was obtained (1) the application of NPK fertilizer increased the growth of sweet corn, (2) the application of horse manure compost increased the growth of sweet corn, (3) There was no increase in growth of sweet corn due to the combination treatment of NPK fertilizer and horse manure compost

Differential Survival of Generic E. coli and Listeria spp. in Northeastern U.S. Soils Amended with Dairy Manure Compost, Poultry Litter Compost, and Heat-Treated Poultry Pellets and Fate in Raw Edible Radish Crops

Composted or heat-treated Biological Soil Amendments of Animal Origin (BSAAO) can be added to soils to provide nutrients for fresh produce. These products lower the risk of pathogen contamination of fresh produce when compared with use of untreated BSAAO; however, meteorological conditions, geographic location, and soil properties can influence the presence of pathogenic bacteria, or their indicators (e.g., generic E. coli) and allow potential for produce contamination. Replicated field plots of loamy or sandy soils were tilled and amended with dairy manure compost (DMC), poultry litter compost (PLC), or no compost (NoC) over two different field seasons, and non-composted heat-treated poultry pellets (HTPP) during the second field season. Plots were inoculated with a three-strain cocktail of rifampicin-resistant E. coli (rE.coli) at levels of 8.7 log CFU/m2. Direct plating and most probable number (MPN) methods measured the persistence of rE.coli and Listeria spp. in plots through 104 days post-inoculation. Greater survival of rE. coli was observed in PLC plots in comparison to DMC plots and NoC plots during year 1 (P < 0.05). Similar trends were observed for year 2, where rE. coli survival was also greater in HTPP amended plots (P < 0.05). Survival of rE. coli was dependent on soil type, where water potential and temperature were significant covariables. Listeria spp. were found in NoC plots, but not in plots amended with HTPP, PLC or DMC. Radish data demonstrate that PLC treatment promoted the greatest level of rE.coli translocation when compared to DMC and NoC treatments (P < 0.05). These results are consistent with findings from studies conducted in other regions of the US and informs Northeast produce growers that composted and non-composted poultry-based BSAAO supports greater survival of rE. coli in field soils. This result has the potential to impact the food safety risk of edible produce grown in BSAAO amended soils as a result of pathogen contamination.

Inokulasi Mikoriza pada Media Tanam Campuran Kompos Kotoran Kambing Terhadap Pertumbuhan Bibit Kakao

<p>Improvements in cocoa cultivation techniques need to be done by adding goat manure as a mixture of planting media to improve the physical properties of the soil in order to make it easier for roots to develop. This objective of this study was to determine concentration of mycorrhizae, the best growing media for cocoa seedlings, and interaction on the growth of cocoa seedlings. The method used was randomized block design with two factor. The first factor was the inoculation of mycorrhizae consisting of four levels: without inoculation of mycorrhizae 10 g/plant, 20 g/plant, and 30 g/plant. The second factor was the growing media with three levels of growing media: top soil, top soil + goat manure compost (1:1), and top soil + goat manure compost (1:2). The results showed that the growing media had a significant effect on the height and volume of plant roots. Growing media of top soil produced the best average seedling by 38.06 cm and root volume by 4.39 cm3. The interaction of giving mycorrhizae with growing media had a significant effect on root volume with the best treatment 10 g/plant mycorrhizae and top soil by 5.67 cm3. The results analysis of root infection by arbuscular mycorrhizal fungi showed the highest infection in the 20 g/plant mycorrhizae and top soil by 80%. Application of mycorrhizae with growing media can increase cocoa yield and growth. Planting media mycorrhizae infected to soil can affect cocoa seedling.</p>

Characterization of a highly xylose tolerant β-xylosidase isolated from high temperature horse manure compost

Background There is a continued need for improved enzymes for industry. β-xylosidases are enzymes employed in a variety of industries and although many wild-type and engineered variants have been described, enzymes that are highly tolerant of the products produced by catalysis are not readily available and the fundamental mechanisms of tolerance are not well understood. Results Screening of a metagenomic library constructed of mDNA isolated from horse manure compost for β-xylosidase activity identified 26 positive hits. The fosmid clones were sequenced and bioinformatic analysis performed to identity putative β-xylosidases. Based on the novelty of its amino acid sequence and potential thermostability one enzyme (XylP81) was selected for expression and further characterization. XylP81 belongs to the family 39 β-xylosidases, a comparatively rarely found and characterized GH family. The enzyme displayed biochemical characteristics (KM—5.3 mM; Vmax—122 U/mg; kcat—107; Topt—50 °C; pHopt—6) comparable to previously characterized glycoside hydrolase family 39 (GH39) β-xylosidases and despite nucleotide identity to thermophilic species, the enzyme displayed only moderate thermostability with a half-life of 32 min at 60 °C. Apart from acting on substrates predicted for β-xylosidase (xylobiose and 4-nitrophenyl-β-D-xylopyranoside) the enzyme also displayed measurable α-L-arabainofuranosidase, β-galactosidase and β-glucosidase activity. A remarkable feature of this enzyme is its ability to tolerate high concentrations of xylose with a Ki of 1.33 M, a feature that is highly desirable for commercial applications. Conclusions Here we describe a novel β-xylosidase from a poorly studied glycosyl hydrolase family (GH39) which despite having overall kinetic properties similar to other bacterial GH39 β-xylosidases, displays unusually high product tolerance. This trait is shared with only one other member of the GH39 family, the recently described β-xylosidases from Dictyoglomus thermophilum. This feature should allow its use as starting material for engineering of an enzyme that may prove useful to industry and should assist in the fundamental understanding of the mechanism by which glycosyl hydrolases evolve product tolerance.

Effects of Onion Residue, Bovine Manure Compost and Compost Tea on Soils and on the Agroecological Production of Onions

Organic solid wastes are rarely considered when planning for rural production in Argentina. Onion production in the low valley of Río Colorado (Buenos Aires) generates between 12,000 and 20,000 Mg year−1 of vegetal wastes (i.e., leaves, stems, skins, roots) from harvesting, cleaning and classification of bulbs, causing many problems with their management. The aim of this work is to study the effect of different doses of onion residue-bovine manure compost and onion residue-bovine manure compost tea on the soil physicochemical properties, microbial activity and agroecological onion production in sandy soil. Results showed that the highest dose of compost caused the highest effects on soil pH, electrical conductivity and nutrient content. Soil enzymatic activities were already high in the soil before the compost was applied, which may have contributed to the small effect caused by any dose on soil activity. A significant positive effect on bulb weight and organic onion yield were found as a result of the amendment and growing season. In conclusion, agroecological production of onion with the addition of a 300 kg N ha−1 compost and compost tea guarantee yields comparable to those of conventional fertilization, as occurred during the two growing seasons of this study.