Effects of dietary supplementation with low levels of organic sources of trace minerals in place of normal levels of their inorganic salts and phytase on growth performance and mineral metabolism were evaluated in two studies using pullets of white and brown shell laying strains. The organic sources were proteinates of copper, iron, manganese and zinc and selenium yeast. A corn-soybean meal diet was fed alone, plus inorganic minerals or plus organic minerals, and with or without phytase in a 3 x 2 factorial arrangement. Twelve groups of 16 pullets, 2 weeks old, were used per treatment. Compared with inorganic minerals, feeding no mineral supplement or organic minerals significantly (P<0.05) decreased manure Cu, Fe and Zn for white pullets and Cu, Fe, Mn and Zn for brown pullets. Dietary phytase significantly reduced manure Fe, P and Ca for white pullets and Fe, Mn, Zn, P and Ca for brown pullets. Adding phytase to diets containing inorganic minerals reduced manure Zn concentration for white pullets and manure Fe, Mn, Zn, P and Ca concentrations for brown pullets. These studies indicate manure levels of trace minerals can be decreased by using low levels of organic mineral supplements and phytase in pullet diets.

Manure from animal farms and sewage sludge contain pathogens and opportunistic organisms in various concentrations depending on the health of the herds and human sources. Other than for the presence of pathogens, these waste substances are excellent nutrient sources and constitute a preferred organic fertilizer. However, because of the pathogens, the risks of infection of animals or humans increase with the indiscriminate use of manure, especially liquid manure or sludge, for agriculture. This potential problem can increase with the global connectedness of animal herds fed imported feed grown on fields fertilized with local manures. This paper describes a simple, easy-to-use, low-tech hygienization method which conserves nutrients and does not require large investments in infrastructure. The proposed method uses the microbiotic shift during mesophilic fermentation of cow manure or sewage sludge during which gram-negative bacteria, enterococci and yeasts were inactivated below the detection limit of 3 log10 cfu/g while lactobacilli increased up to a thousand fold. Pathogens like Salmonella, Listeria monocytogenes, Staphylococcus aureus, E. coli EHEC O:157 and vegetative Clostridium perfringens were inactivated within 3 days of fermentation. In addition, ECBO-viruses and eggs of Ascaris suum were inactivated within 7 and 56 days, respectively. Compared to the mass lost through composting (15–57%), the loss of mass during fermentation (< 2.45%) is very low and provides strong economic and ecological benefits for this process. This method might be an acceptable hygienization method for developed as well as undeveloped countries, and could play a key role in public and animal health while safely closing the nutrient cycle by reducing the necessity of using energy-inefficient inorganic fertilizer for crop production.

<p>Den snabba utvecklingen och urbaniseringen i stora delar av Kina har ett flertal konsekvenser för miljön. Yangtzedeltats ytvatten är till stor del eutrofierade, delvis p.g.a. diffusa förluster från jordbruket. I denna studie har kväve- och, till viss del, fosforflöden och förluster från två odlingsrutor i ett intensivt odlat grönsaksfält i ett tätortsnära område i Nanjing, med hög tillförsel av organiskt gödsel, undersökts med hjälp av den fältskaliga simuleringsmodellen GLEAMS. GLEAMS parametriserades och kalibrerades mot mätvärden av jordens vatten- och kväveinnehåll. Ett scenario med minskad kvävetillförsel simulerades sedan.</p><p>Simuleringen av vattenhalten i de olika horisonterna var inte utmärkt. Den simulerade mängden mineralkväve i marken var avsevärt lägre än den uppmätta. Detta kan bero på en felaktig simulering av mineraliseringen av organiskt kväve eller en för långsam nedbrytning av gödsel. Det är också möjligt att felen i vattensimuleringarna bidrog till underskattningen av mängden mineralkväve i marken. Simuleringarna på de båda odlingsrutorna gav liknande resultat, förutom att ruta B hade 20% större förluster av N via simulerad erosion och läckage. För fortsatt simulering av alternativa odlingsmetoder bör modellens parametrisering förbättras, särskilt vad avser parametrar kopplade till gödselns mineralisering.</p> / <p>Many parts of China are going through a rapid development and urbanization resulting in various environmental impairities. The Yangtze Delta Region surface water bodies are affected by eutrophication, partly caused by diffuse losses from agriculture. In this study, nitrogen, and to some extent also phosphorus, flows and losses from two plots in an intensively cultivated vegetable field in a peri-urban area of Nanjing, with a high input of organic fertilizer, were analysed by the use of the field-scale simulation model GLEAMS. The GLEAMS model was parameterized and calibrated against measurements of soil water and nitrogen content in two plots. A scenario with a reduced input of nitrogen was then simulated.</p><p>The resemblance between simulated and measured water content in the different soil layers was quite poor. The simulated inorganic nitrogen content in the soil was significantly lower than the measured during great parts of the simulation period. This could be due to an inappropriate simulation of the mineralization of organic N under these conditions, or an underestimated decomposition rate of manure. It is also possible that the poor water simulations contributed to the underestimated inorganic N content in the soil. There were similar results for the two plots, except for an unexplained 20% increase in leaching and erosion losses of N in Plot B. For simulation of scenarios to find best management practices, the model parameterization should be further refined.</p>

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Promotion of agroforestry practices in sub-Sahara Africa may help sustain subsistent food and wood production by integrating trees and crops on farmlands to replenish soil fertility and improve crop yield. Using rotational woodlot and pigeonpea intercropping systems in semi-arid Tanzania as case studies, my research screened suitable tree species to increase fuelwood supply and examined mechanisms for reducing tree-crop competition. By adopting nutrient use efficiency (the ratio of biomass yield to nutrient uptake) as a criterion, I found that selecting tree species of low wood nutrient concentrations would minimize nutrient exports by 42 – 60 %, thus reducing soil nutrient depletion while concurrently sustaining local fuelwood supply harvested from rotational woodlots. Currently smallholder farmers cannot afford to replenish soil fertility because of high fertilizer costs. However, 5-year tree fallowing raised soil N and P levels for maize culture as high as those from recommended fertilizer applications. Post-fallow maize yield was also increased significantly over natural fallow practices. Apparently there is a trade-off between yields of maize and fuelwood under rotational woodlot culture providing farmers the choice to proportion tree and crop composition based on priority demands. An alternative practice of intercropping pigeonpea with maize may also rapidly replenish soil fertility as well as enhance maize yield when competitive interactions between trees and crops are controlled. Vector analysis revealed that such interactions suppressed biomass yields of maize and pigeonpea by 30 % and 60 %, respectively, due to limited soil nutrients and/or moisture. Optimizing yields of both crops would require prescribed fertilizer addition when intercropped, but dose rates can be lowered by half under the improved fallow system due to alleviating interspecific competition. My findings form the basis of a plea for greater use of rotational woodlot and pigeonpea intercropping systems in semi-arid areas. I conclude that smallholder farm management of rotational agroforestry systems can be significantly improved by refining tree selection criteria and mitigating nutrient competition between trees and crops to maintain food and fuelwood production.

The aim of the paper: to investigate the effect of microclimatic factors on the process of ammonia emission from manure, and evaluate possibilities to reduce ammonia emission from cowsheds by controlling these factors. The completed analysis of microclimatic factors in various naturally ventilated cowsheds revealed patterns of variation in ammonia concentration depending on air temperature in the barn. While analysing the process of ammonia evaporation from the manure, the effect of interacting environmental factors on the intensity of evaporation was evaluated. The effect of temperature, ventilation intensity and drying of manure surface on the intensity of ammonia evaporation process from manure was determined and proved. Theoretical and experimental presumptions were made for the investigation of the effect of the crust formation at the manure surface on ammonia diffusion process. Based on the obtained results, ammonia emission from naturally ventilated cowsheds with various engineering solutions can be predicted, and equipment reducing the ammonia emission from them can be installed. / Darbo tikslas ˗ Ištirti mikroklimato veiksnių įtaką amoniako emisijos procesui iš mėšlo ir įvertinti galimybes juos valdant sumažinti amoniako emisiją iš karvidžių. Ištyrus mikroklimato veiksnius įvairiose natūraliai vėdinamose karvidėse, nustatyti amoniako koncentracijos kaitos dėsningumai priklausomai nuo oro temperatūros tvarte. Analizuojant amoniako garavimo iš mėšlo procesą, įvertinta tarpusavyje sąveikaujančių aplinkos veiksnių komplekso įtaka garavimo intensyvumui. Nustatyta ir įrodyta temperatūros, vėdinimo intensyvumo ir mėšlo paviršiaus džiūvimo įtaka amoniako garavimo iš mėšlo proceso intensyvumui. Sukurtos teorinės ir eksperimentinės prielaidos tirti mėšlo paviršiuje besiformuojančios plutos įtaką amoniako difuzijos procesui. Pagal gautus rezultatus galima prognozuoti amoniako emisiją iš natūraliai vėdinamų karvidžių su įvairiais inžineriniais sprendimais ir diegti priemones mažinančias amoniako emisiją iš jų.

Les activités d'élevage sont responsables de la dissémination dans l'environnement d'un grand nombre de polluants, dont les perturbateurs endocriniens (PE) qui affectent le système endocrinien des organismes vivants. La disruption endocrinienne se fait par la liaison des PE sur des récepteurs nucléaires spécifiques dont le récepteur aux strogènes ERα, le récepteur à la dioxine AhR, le récepteur X aux pregnanes PXR, le récepteur aux androgènes AR et le récepteur régulant la prolifération des peroxysomes, PPARγ. Les hormones stéroïdes sont particulièrement actives sur le récepteur ERα. Elles sont naturellement produites par les animaux et concentrées dans les effluents d'élevage épandus sur les sols agricoles. Ce travail de thèse s'est focalisé sur l'étude du devenir des hormones dans des systèmes de gestion des lisiers porcins, à échelle réelle ou contrôliée, en conditions anaérobies ou aérobies. Au préalable, la méthodologie pour l'analyse des hormones dans le lisier a été validée. Les résultats montrent que les hormones sont principalement contenues dans la fraction solide; dans cette fraction les mesures d'activité strogénique (ERα) ont révélé une activité non explicable par les concentrations en hormones, suggérant la présence d'autres composés ayant une activité sur ERα. La quantification des nonylphénols, actifs sur ERα n'a pas permis d'expliquer cette activité. L'étude d'autres voies de perturbation endocrinienne via l'activation des récepteurs AhR, PXR, PPARγ et AR a permis de détecter une forte activité sur le récepteur AhR. L'analyse chimique de cette fraction a montré l'absence de dioxines et d'hydrocarbures aromatiques polycycliques, suggérant l'implication d'autres PE qui restent à être identifiés. Dans les systèmes de traitement sous conditions réelles ou contrôlées, les conditions aérobies sont plus efficaces pour éliminer les hormones et les activités strogéniques et « dioxin-like » associées, bien que cette dernière semble plus récalcitrante. / Livestock activities are responsible for the release of a wide range of pollutants in the environment. Among these pollutants, the endocrine disruptors (ED) can affect the endocrine functions of living organism. The endocrine disruption occurs via the binding of ED to specific nuclear receptors such as the estrogen receptor ERα, dioxin receptor AhR, pregnane-X-receptor (xenobiotics), androgen receptor AR and peroxysome proliferator-activated receptor γ, PPARγ. Steroid hormones are particularly active on ERα receptor. Animals naturally produce high amounts of hormones which are concentrated in manure used for land spreading. This study deals with the fate of hormones in swine waste management facilities at full or pilot scale, under both anaerobic and aerobic conditions. Firstly, the analysis of hormones in such a complex matrix was validated. Hormones are mainly present in the solid fraction of the manure. At the same time, estrogenic activity measurements showed that in this solid fraction, the estrogenic activity cannot be explained by hormones; which suggest the presence of other compounds active on ERα. Nonylphenols concentrations cannot explain this additional activity. The study of the other pathways of endocrine disruption through the activation of AhR, PXR, PPARγ, and AR allowed to measure high AhR activity in the solid fraction of manure. The chemical analysis of this fraction did not show the presence of dioxins and polycyclic aromatic hydrocarbons traditionally involved in such kind of activity; it suggests the presence of other AhR ligands that remain to be identified. In swine manure treatment systems, aerobic conditions were more efficient to remove hormones and the associated estrogenic and AhR activities, even if this last seemed to be more recalcitrant.

Studies have shown that significant amounts of nitrate-N is leached beyond root zones of annual crops while small amounts of nitrate-N is leached beyond the root zones of perennial forage grasses. This study investigated short-term ammonium-N persistence and root nitrogen content of annual crop and perennial forage grasses following application of pig manure to a sandy loam soil at Carman, Manitoba. Results showed that ammonium-N in liquid pig manure (LPM) amended treatment peaked four days after manure application (DAM) in perennial cropping system (PCS; 50 - 74 kg ha-1) and annual cropping system (ACS; 18 - 29 kg ha-1) in 2014 and 2015. Ammonium-N persisted up to 7 DAM in LPM amended PCS, but did not persist beyond 4 DAM in LPM amended ACS. Ammonium-N measured in solid pig manure (SPM) amended ACS and PCS was low throughout the sampling days in both years. There was a greater percentage increase in accumulation of nitrate-N at 15 - 30 cm soil depth of LPM and SPM amended ACS than PCS. In both years, dry weight below-ground plant biomass ranged from 5,258 to 9,627 kg ha-1 at 0 - 60 cm depth in PCS while that of ACS ranged from 1,088 to 1,456 kg ha-1. Also, root N content in PCS ranged from 43 to 118 kg N ha-1 in both years while that of ACS ranged from 9 to 20 kg N ha-1. In conclusion, ammonium-N persisted longer in PCS than ACS in the short-term and total plant N was greater in PCS than ACS. Greater total plant N in PCS than ACS was mainly due to its greater root N content rather than above-ground N uptake. The order of magnitude of the difference in root N content (34 to 98 kg N ha-1) between ACS and PCS was sufficient to account for the 20 to 60 kg N/ha of nitrate-N leached in ACS in previous study at the same site. / October 2016

Malawi is one of many countries throughout the world struggling with massive amounts of water hyacinths (Eichornia crassipes) in the country’s fresh water resources.  In nutrient-rich ecosystems where the aquatic weed has no natural enemies it will reproduce very rapidly with the consequence that lakes become overgrown, water flow in rivers is reduced, and other water organisms becomes excluded. At the same time, the plants form a good breeding place for species carrying tropical diseases for example Malaria and Bilharzia. Water hyacinths are usually more of a problem for poorer countries since there are often great economic losses caused by the weed and to control their relative abundance is costly. In Malawi, 99 % of the produced electricity is based on water resources, mainly through hydropower turbines in the main river, Shire River. Water hyacinths, aggregated as islands, floating along the river and clogging the turbines cause repeated electricity black-outs and approximately 140 megawatt power is lost every day. To counter the weed interference with the electricity supply, there are great amounts of water hyacinths harvested every day and dumped along the road, with no further disposal plan. In this report, soil from one local dumping area is analysed to determine if such places are leaching nutrients or metals to the surrounding environment.  Water hyacinths contain naturally high values of nutrients and farmers use these harvested plants as a green manure to improve soil properties on agricultural land. This paper aims to examine levels of metal in water hyacinths used as green manure. This is of interest since water hyacinths have the ability to effectively absorb substances from the water body which could pose a risk for potentially toxic elements (PTEs) to accumulate in the agricultural soil and subsequently in crops. Sampling and analyses were carried out with standard methods. Metal and nutrient levels in the analysed samples were obtained through detection with atomic absorption spectrophotometry (AAS), ion chromatography (IC) and UV/VIS spectrophotometry at the Department of Chemistry of Chancellor College in Zomba, Malawi. None of the investigated metal ions (Cr, Pb, Cd) were found in the analysed water hyacinths and since soil sampling was done during the dry season this thesis cannot determine if the dumping areas are leaching nutrients. Relatively high amounts of total phosphorus were found in the plants. Overall, the conclusion is that there is no risk of using water hyacinths harvested in Shire River as a green manure on agricultural land.

Volatile fatty acids (VFAs) are important building blocks for the chemical industry. These acids can be produced through environmentally friendly processes from a variety of wastes, such as food waste, sludge and cow manure, through anaerobic digestion (AD). The main objective of this thesis was to investigate which operating parameters (e.g. pH, retention time, mix of substrate etc.) are optimal for producing VFAs as efficiently as possible, through AD batch processes. The highest VFA concentration was reached at pH 10 and at day 11 when food waste and sludge were used as substrate to a value of 15.4 g/L, corresponding to 0.77 g VFAs/ g of VSfed. Highest VFA concentration where cow manure was used as substrate was reached on day 10 and with a value of about 10 g/L corresponding to 0.51 g VFAs/ g VSfed. / Flyktiga fettsyror (VFAs) är en viktig byggsten inom den globala kemiindustrin. Dessa fettsyror kan produceras med hjälp av miljövänliga processer där en mängd olika sorters avfall, som t.ex. matavfall, avloppsslam och koavföring kan fungera som substrat, genom anaerobisk rötning. Det huvudsakliga målet med den här kandidatuppsatsen var att utreda vilka de optimala driftförhållanden var för särskilt utvalda driftparametrar (t.ex. pH, retentionstid, mix av substrat etc.) för att producera flyktiga fettsyror så effektivt som möjligt, genom anaerobisk rötning. Högst koncentration av VFAs nåddes vid pH 10 på dag 11 när matavfall och avloppsslam användes tillsammans som substrat till ett värde på 15 g/L, vilket motsvarar en avkastning på 0.77 g VFAs / g VSin. Högst VFAs-koncentration när koavföring användes som substrat nåddes på dag 10 med ett värde på 10 g/L, motsvarande en avkastning på 0.51 g VFA/ g VSin.