Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The aim was compare impact of NPK with the other types of fertilization: 0, N, PK, NK and NP on plants of chosen varieties. The experiment was treated on soil less convenient to intensive planting at an altitude of 400 m and conventionally

The leaching of nitrogen (N) and phosphorus (P) from the rootzone of cropping systems is a major contributor of non-point source pollution resulting in deterioration of fresh water supplies. An escalating world population is forcing further intensification of agricultural production practices and the identification of suitable and effective management practices to reduce N and P leaching losses is becoming ever more important. Such leaching losses are, however, extremely challenging to measure and quantify due to uncertainties associated with the estimation of deep drainage and N and P concentrations in this drainage water. SWB-Sci is a locally developed, mechanistic crop model to which N and P subroutines have been added to enable analysis of leaching losses at the local scale. This involved novel approaches to estimate the effects of N deficiencies on yield; to simulate crop P demand, uptake and stress effects; to simulate banded P fertilizer applications; and to estimate incomplete solute mixing. New equations to estimate the size of the Labile P pool from soil P tests commonly used in South Africa, and guidelines on the classification of South African soils as calcareous, slightly weathered or highly weathered which is required to simulate P, were also developed. The upgraded more versatile model was tested using historical datasets from the Netherlands, Kenya and South Africa, and performed well in simulating N and P dynamics in maize and wheat cropping systems. Variables tested included aboveground dry matter production, yield, leaf area index, aboveground crop N and P mass, grain N and P mass, soil water content ABSTRACT xvii and soil inorganic N levels. A study was also conducted on a large drainage lysimeter into which suction cups and wetting front detectors were installed, and data from this experiment together with the SWB-Sci model was used to study vertical solute movement more closely. As hypothesized, wetting front detector nitrate (NO3-) and P concentrations were observed to align closely with simulated mobile phase concentrations, and suction cup NO3- concentrations were observed to align closely with simulated immobile phase concentrations. These results confirm that monitoring and modelling can be used together to improve understanding and obtain more accurate estimates of N and P leaching losses, and further work on this approach is recommended for a wide range of soils and cropping systems. Finally, long-term modelling with the SWB-Sci model was used to analyse and compare N and P leaching losses from a dryland versus an irrigated monoculture maize production system. Over a 30 year simulation period, irrigated maize was estimated to leach considerably higher loads of N and P (~ 4-fold higher). For dryland production, zero leaching was observed for consecutive years on several occasions, with major leaching losses associated with high rainfall events. A ‘room for rain’ irrigation scheduling management practice was estimated to reduce N leaching by 12% and P leaching by 14%, while a crop rotation system which incorporated wheat grown over the winter months was estimated to reduce N leaching by 23% and P leaching by 24%. From this study, long-term modelling was confirmed as an effective approach to investigate N and P leaching losses, to assist with the planning and design of field trials, and to assess the effectiveness of best management practices. It is envisaged that SWB-Sci will continue to evolve as a valuable tool for analysing and reducing N and P leaching losses from cropping systems to further reduce non-point source pollution. / Thesis (PhD)--University of Pretoria, 2010. / Plant Production and Soil Science / unrestricted

Ecological stoichiometry is a useful tool for understanding of ecological dynamics and related processes. There are only rare informations about nutrient cycling and nutrient dynamics in plant- soil system in restoration areas after coal mining. Different plant species have developed own strategies and treat differently with nutrients which can influence nutrient cycling and consequent nutrient return to the soil. In thesis, I investigated ecological stoichiometry as one of key factors which controls soil development in post mining sites. In general introduction, known facts are summarized about e.g. plant traits, decomposition process, nutrient cycling and consequences for soil development and restoration practices. But still, relationship between leaves, plant litter, and soil is poorly understood in restoration areas. The results of a doctoral thesis are presented in five papers, out of which three have been published, one has been already submitted and one manuscript is prepared for publication in an international journal with impact factor. In the first presented publication, the influence of soil fauna was studied (especially earthworms) on soil development. Soil development differed significantly between sites afforested with different tree species and it is strongly influenced by the...

No description available.

Water is a prerequisite for life on our planet. Due to climate change and pollution, water availability for agricultural production, industry and households is increasingly put at risk. With agriculture being the largest water user as well as polluter worldwide, we estimate anthropogenic nitrogen and phosphorus emissions to fresh water related to global crop production at a spatial resolution level of 5 by 5 arc min and calculate the grey water footprints (GWF) related to EU-27's crop production. A multiregional input-output model is used to trace the the GWF embodied in the final consumption of crop products by the EU-27. The total GWF related to crop production in the EU-27 in 2007 was 1 × 1012 m3/year. Spain contributed about 40% to this total. Production of cereals (wheat, rice and other cereals) take the largest share, accounting for 30% of the GWF, followed by fruits (17%), vegetables (14%), and oil crops (13%). The total agricultural GWF of the EU-27 related to crop consumption was 1830 billion m3/year, which is 3700 m3/year per capita on average. Overall, the EU-27 was able to externalize about 41% of the GWF to the rest of the world through imports of crop products.

Thesis (M.S.)--Indiana University, 2008. / Title from screen (viewed on June 3, 2009). Department of Earth Science, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Lin Li, Pierre Jacinthe, Gabriel M. Filippelli. Includes vita. Includes bibliographical references (leaves 78-81).

An increasing demand for food, and in particular animal products, is putting high pressure on natural resources, often at places distant from the consumption. Nitrogen and phosphorus are essential nutrients in food production but an excessive use can cause environmental impacts such as eutrophication that can harm ecosystems services vital to local communities. This study developed sub-national spatially explicit N and P footprints that were extended with an assessment of nutrient leaching risk and risk of impact on biodiversity. The consumption of N and P in Brazilian soybean production at municipal level was estimated for the whole of Brazil as well as for UK soybean demand. This was then combined with the risk of nutrient leaching (Nrisk and Prisk) and species richness (Nbio and Pbio). The results showed high Nbio and Pbio in Mato Grosso, Paraná, and Rio Grande do Sul. The same analysis of the effects of UK soybean demand showed a higher risk of impacts in Rondônia and less in Paraná and Rio Grande do Sul compared to total Brazilian soybean production. A municipal case study showed that the demand of Brazilian soybean in the UK, EU, and China generated different spatial patterns of impact risks at municipal level. Spatially explicit footprints that also encompass risks of impacts are important for being able to identify the responsible consumer and parts of the supply chain where sustainability interventions will be most effective. There are several opportunities for future development within this research field as data availability is continuingly increasing.

Submitted by YEMALL ALEXANDER MAIGUAL ENRIQUEZ (alex.feisunesp@gmail.com) on 2018-05-08T00:18:49Z No. of bitstreams: 1 TESE MBBR-ICT-7-MAY-2018.pdf: 5856438 bytes, checksum: f1c36146463af4ee146d48da7c3be308 (MD5) / Approved for entry into archive by Bruna Bacalgini null (bruna@sorocaba.unesp.br) on 2018-05-08T14:17:18Z (GMT) No. of bitstreams: 1 enriquez_yam_dr_soro.pdf: 5856438 bytes, checksum: f1c36146463af4ee146d48da7c3be308 (MD5) / Made available in DSpace on 2018-05-08T14:17:18Z (GMT). No. of bitstreams: 1 enriquez_yam_dr_soro.pdf: 5856438 bytes, checksum: f1c36146463af4ee146d48da7c3be308 (MD5) Previous issue date: 2018-03-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A aquicultura é uma atividade de produção de espécies hidrobiológicas sob condições controladas. Esta atividade tem evoluído nos processos produtivos, mas estão gerando águas residuárias, quando lançadas diretamente nos corpos de água constituindo riscos potenciais à saúde. O reator de leito móvel com biofilme (MBBR) é uma variação do processo de lodos ativados. É um sistema de tratamento de efluentes que contem biofilme que cresce aderida aos suportes, que se movem livremente no volume do reator. O objetivo desta pesquisa foi determinar a eficiência na remoção de material, nitrogenado no MBBR dos efluentes gerados num sistema de recirculação para aquicultura “SRA”. O sistema MBBR com circulação (SC) - e com aeração (SA) obteve remoções medias de 38,7% para Nitrogênio Total Kjedahl (NTK), 28,9% de fósforo total, 44,5% de DBO, Nitrogênio Amoniacal Total (NAT) de 40% e 38,9% para amônia não ionizada e para nitrito foi 59,3%. Os sólidos Totais (ST), Sólidos Suspensos Totais (SST) e Sólidos Voláteis Totais (SVT) tiveram remoções de 28,0%, 45,9% e 57,4% respectivamente. Durante o período avaliado houve aumento do biofilme nos dois reatores. No MBBR-SA foi verificada a presença de protozoários, microinvertebrados e estruturas filamentosas semelhantes a estreptococos. No MBBR-SC, bactérias na forma de cocos, diplococos e estreptococos. Nas analises realizadas com MEV nos lodos dos dois sistemas foi encontrado traços de silício, alumínio, zinco, fósforo, sódio e magnésio. Também foi encontrado bactérias do tipo vibrio spp, bacilus spp, além da formação de aglomerados. As analises térmicas feitas nos lodos indicaram que houve perda de umidade até os 150°C. A maior parte da massa se perde entre 220°C e 580°C, faixa onde sofrem transformação térmica as proteínas, lipídeos, carboidratos, ácidos graxos, restos de paredes celulares bacterianas. Após os 600°C existe o restante, as cinzas são compostas por carbonatos e outros minerais transformando-se em matérias cristalinos, com baixa variação na massa. / Aquaculture is an activity of production of hydrobiological species under controlled conditions. These activities have evolved in the productive processes, but are producing wastewater, when thrown directly into bodies of water constituting potential health risks. The moving bed biofilm reactor (MBBR) is a variation of the activated sludge process. It is an effluent treatment system containing biofilm growing attached to the carriers, which move freely in the reactor volume. The aim of this research was to determine the efficiency in the removal of nitrogenous compounds in MBBR from the effluents generated in a recirculating aquaculture system "RAS". The MBBR system with circulation (CS) - and with aeration (AS) obtained mean removals of 38.7% for NTK, 28.9% of total phosphorus, 44.5% of BOD, 40% TAN and 38.9% for non-ionized ammonia and for nitrite was 59.3%. Total Solids (TS), Total Suspended Solids (TSS) and Total Volatile Solids (TSV) had removals of 28.0%, 45.9% and 57.4% respectively. During the evaluated period there was an increase of biofilm in the two reactors. In the MBBR-AS the presence of protozoa, microinvertebrates and filamentous structures similar to streptococcus was verified. Also, in MBBR-CS was verified coccus, diplococcus and streptococcus bacteria. In the analyzes performed with SEM in the sludge of the two systems, traces of silicon, aluminum, zinc, phosphorus, sodium and magnesium. Vibrio and bacillus type bacteria were present and besides granule formation. Thermal analyzes indicated that there was in the sludge moisture loss until 150°C. Most of the mass is loss between 220°C and 580°C, where they undergo thermal transformation of proteins, lipids, carbohydrates, fatty acids, remains of bacterial cell walls. After the 600°C the ashes are composed of carbonates and other minerals transforming into crystalline materials, with low mass variation. / CAPES: 12616-13-3

The objectives of this research were to examine some representative surface waters in the Yazoo River Basin (YRB) during the growing season for a few selected herbicides; to compare the type and abundance of pesticides in the atmosphere at a agricultural and an urban site; to determine the load of nitrogen and phosphorus being discharged from the YRB to the Mississippi River and ultimately the Gulf of Mexico; to determine how the adsorptive properties of a common Delta soil differ under no-tillage (NT) versus conventional tillage (CT) for two commonly used herbicides; and to validate the Soil and Water Assessment Tool (SWAT) model for herbicide runoff in the YRB. Herbicides, in low concentrations (generally less than 10 parts per billion) were frequently detected in 3 streams in the YRB throughout the growing season. Pesticides were detected in air and rain samples from both urban and agricultural areas. The concentrations in the agricultural area generally were an order of magnitude higher and types of pesticides detected were different: more insecticides in the urban area and more herbicides in the agricultural area. The annual load of nitrogen being contributed to the Mississippi River from the YRB was less than what might be expected based on discharge, and the load of phosphorus was slightly higher than what might be expected. The amount of atrazine and fluometuron adsorbed was similar for a soil under CT and NT, but much more herbicide was adsorbed by the NT soil. At the scale of the Bogue Phalia Basin (too large for specific information to be available and too small for averaging to eliminate the need for site specific data) there are considerable uncertainties associated with input data and these, together with the simplifying assumptions within the model, mean that SWAT should not be used to predict the exact date, time, and concentration of a pesticide in a stream. However, the model does offer the potential to assess the likelihood of contamination of surface waters by a given compound in a given situation and as such could provide a useful tool for planning, management and regulatory purposes.