Life Sciences Commons^™

Vegetation Changes In Southeast Australian Temperate Grasslands, D. L. Garden, T. P. Bolger

IGC Proceedings (1997-2023)

In temperate areas of southeast Australia, the combined effects of tree clearing, grazing, application of fertilizer and the introduction of exotic species have modified the original grasslands. This paper describes these changes and attempts to explain them in terms of ecological principles derived from North American grasslands. Stability of the original grasslands appears to have been due to the lack of disturbance and the slow rates of nitrogen (N) cycling within them. Increased N cycling after disturbance has allowed invasion of species better adapted to higher N status, particularly exotic annual grasses and weeds. The present composition of grasslands, in …

Field Evaluation Of Struvite As A Phosphorus Source, Niyi Sunday Omidire

Graduate Theses and Dissertations

Phosphorus (P) is an element that is crucial in many biological processes in all forms of life and is not substitutable. Excess P in wastewaters leading to the degradation of receiving waters or eutrophication once released is a major environmental concern. Removal of excess P from wastewater as the mineral struvite (MgNH4PO4·6H2O) could be a promising solution to reduce P discharge into receiving waters and can potentially provide a valuable fertilizer-P source for agricultural production. The objectives of this project were to evaluate the effects of: 1) chemically precipitated struvite (CPST), compared to triple superphosphate (TSP) and an unamended control …

Influence Of Seasonality And Agricultural Practices On Soil Microbes In Kamishihoro, Japan, Y. Madegwa, Y. Uchida

IGC Proceedings (1997-2023)

Soil microbes are important for maintenance of soil fertility and ecosystem functions. Agricultural practices such as land use, seasonality and fertilizer application effect the soil microbial community structure. However, the effect of these management practices on soil microbes and related functions, especially in one specific region, is still not clear.

Therefore, the study was conducted in Kamishihoro, Japan, to determine effect of land use (cropland, grassland), season (summer, spring) and fertilizer (anaerobic digestate, control) on soil microbial community and functions. Experimental procedure included DNA extraction, quantification, purification, amplification of 16SrRNA (bacterial gene) and Next Generation Sequencing (Ion PGM). Data analysis …

Nitrogen Concentration In Cell Wall Of Warm-Season Perennial Grasses, G. F. C. Lima, Lynn E. Sollenberger, J. E. Moore

IGC Proceedings (1997-2023)

The objectives of this experiment were to evaluate the influence of N fertilizer, age of regrowth, and season on concentration of N in cell-wall fractions of three warm-season perennial grasses (limpograss, [Hemarthria altissima (Poir.) Stapf et C.E. Hubb.], bermudagrass [Cynodon spp.], and bahiagrass [Paspalum notatum Flügge]. The herbage neutral detergent insoluble nitrogen (NDIN) fraction composed almost half of total N in these grasses. Though acid detergent insoluble nitrogen (ADIN) concentrations generally were 80 g kg^-1 of total N or less, this fraction is indigestible and unavailable and composes a significant portion of a nutrient that may …

A Sheep And Catlle Diet Selection Study On A Fertilized Native Sward In Uruguay, Fabio Montossi, E. J. Berretta, G. Pigurina, I. Santamarina

IGC Proceedings (1997-2023)

This study was undertaken during winter, spring and summer 1997, located in the basaltic region of Uruguay to evaluate the effects of stocking rate (SR) and N and P fertilizer application on sward characteristics and on sheep and cattle diet selection and grazing behaviour. The treatments applied were: a) control (C; without fertilizer application using a SR of 0.9 stock units (SU)/ha), b) T1 (with N and P fertilizer application using a SR of 0.9 SU/ha), c) T2 (with N and P fertilizer application using a SR of 1.2 SU/ha) and d) T3 (with N and P fertilizer application using …

Assessing The Effect Of N And P Supply On Dry Matter Yield Of Three Tropical Grasses, O. Topall, C. Jouany, M. Duru, P. Cruz

IGC Proceedings (1997-2023)

The objectives are to study the effects of N and P supply and their interaction, on herbage dry matter yield and nutrient status of three tropical grasses. In order to estimate direct and indirect effects of P supply we express above-ground dry matter production as a function of the herbage nutrient status obtained from plant analysis. Results show that in absence of N, the significant increase in P nutrition status has only moderate consequences on herbage production and suggest that both N and P are limitant for herbage growth. P fertilization results in significant increase in dry matter yield only …