No description available.

Agricultural systems are known to emit nitrous oxide (N2O)---a potent greenhouse gas. The roving flux tower measuring system of Agriculture and Agri-Food Canada was used to make continuous measurements of N2O fluxes in an edible pea field in Western Quebec in 2003-04 and then in an alfalfa-timothy forage field in Eastern Ontario in 2004-05. The experiment was designed to capture, at the field scale, the expected large N2O emissions occurring as a result of fertilizer application for a year, in relation to both large precipitation events and spring thaw. / Growing season N2O emissions averaged 0.5 to 5 mg N2 O-N m-2 d-1 with peaks following snow melt (between 5 and 8 mg N2O-N m-2 d-1) and manure applications (8 to 37 mg N2O-N m-2 d -1). Although generally small (<0.25 mg N2O-N m -2 d-1), emissions were detectable during the fall and winter, indicating the importance of including them in annual emission totals. / The measurements were used to verify the performance of the simulation model DNDC (DeNitrification-DeComposition) in estimating N2O emissions from legumes and in response to dairy manure application. Sensitivity tests were also carried out in which baseline input values were modified. Results suggest that the current model version (DNDC8.9) requires further modification prior to application for estimating greenhouse gas emissions in national accounting systems.

Thesis (M.Sc. (Soil Science)) -- University of Limpopo, 2019 / Phosphorus (P) deficiency has been reported in 30- 40% of global arable land, which poses a huge threat in potato production because of its critical role in the early vegetative development and tuber formation. The use of low cost ground phosphate rock (GPR) as an alternative P fertilizer source has gained recognition. Although GPR contains high P percentage, its direct application is less beneficial immediately due to its low reactivity which makes P unavailable for plant uptake. In this experiment, GPR was co-composted with cattle and poultry manure in order to enhance P acquisition by the potato crop. The aim of this study was to evaluate the potential of phosphocompost application as a cheaper alternative P-source for potato production. The experiment was conducted on Mondial and Valor… potato cultivars at the University of Limpopo Syferkuil Experimental farm in 2015 and 2016. Poultry (PM) and cattle manure (CM)-based phospho-compost mix ratios of 8:2 and 7:3 were applied at 0, 20, 40, 80 and 120 kg P/ha. The trial was laid out in a split plot arrangement fitted into a randomised complete block design with treatments replicated three times. Results indicated statistically significant effects of phospho-compost types on soil pH and available P content at both flowering and harvesting growth stages in 2015 and 2016 with the higher available P content found in the PM-based phospho-composts. In both seasons, highly significant differences in fresh and dry leaf samples among phospho-compost types were obtained. Highly significant season x compost type interaction effects were also recorded on leaf biomass as well as the 2015 tuber weight, with highest tuber weight obtained in plots that received PM7:3-based phospho-compost at 80 t/ha rate. Notwithstanding the non-significant effect of compost type on tuber yield in 2016, higher yield was obtained from PM8:2. Although the grading of tubers showed no significant response to phospho-compost application; the difference between small and medium tubers obtained from 2016 trial was significantly affected by phosphocompost application rates. The CM8:2 mix ratio gave the highest baby tubers (16.87%) while PM7:3 mix ratio gave the highest (36.32%) medium tubers. The grading of the potato tubers revealed a mostly class 1 dominated by baby, small and medium size tubers in the 2015 harvest while the 2016 harvest was also mostly class 1 but dominated by small, medium and large-small size tubers. Tuber size and class were vi most favored by the PM-based phospho-compost applications in both planting seasons. None of phospho-compost types and application rates had significant effect on the measured nutrient concentrations of both plant parts. However, the differences in nutrient concentrations across seasons and plant parts were significant except for Ca. The measure tissue P concentration from the 2016 trial was within the required range suggesting that phospho-compost utilization, particularly the poultry manure-based, in potato production can be beneficial in addressing P deficiency. The PM8:2 mixed ratio resulted in increased soil available P content, potato tuber yield in 2016 and the P concentration across the two plant parts evaluated. The concentration of soil available P and tissue P showed increases with higher application rates albeit non-significance. Future research on the optimum application rate is suggested on a wide range of soils for the various phospho-compost types. / Potato SA and the National Research Foundation (NRF)

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.

Thesis (M.Sc. (Crop Science)) --University of Limpopo, 2012 / Organic tomatoes are increasingly popular with larger market acceptance since organic farming uses limited or no artificial chemicals. Application of organic fertilisers such as cattle manure has potential to boost organic tomato productivity particularly under low input farming systems. However, information is required on the optimum level of manure application on different tomato cultivars to help emerging tomato farmers in South Africa. The objective of this study was to determine the relative response of yield and yield components among selected determinate and indeterminate tomato cultivars using different levels of cattle manure. Two separate field experiments were conducted at the University of Limpopo during 2007 and 2008 using a split plot design with three replications. Two sets of tomato cultivars were included in which one set consisted indeterminate types (Money Maker, Ox Heart and Sweetie) and the other determinates (Roma and Floradade). Cultivars were assigned as the main plot treatments with six rates of manure (0, 10, 20, 30, 40 and 50 in gram per plant) applied as the subplot treatments to each set. Results indicated significant interactions (P ≤ 0.01) between indeterminate tomato cultivars and levels of manure applied for fruit yield and fruit size in both experiments. Plant height showed variation from 78 to168 cm in Experiment I and 87 to 176 cm in Experiment II. During Experiment I fruit number varied from 23 to 91 per plant and 23 to 97 in Experiment II. Significant differences were detected among determinate cultivars on fruit yield varying from 7928 to 3 4705 kg per hectare during Experiment I and 3 169 to 2 9840 kg per hectare during Experiment II. Overall, the best level of manure for maximum fruit yield and greater fruit size was achieved at 40 g per plant in the indeterminate cultivar Sweetie. Conversely, the best level of manure for maximum fruit yield was achieved at 30 g per plant in determinate cultivar Roma. Thus, to achieve maximum yield, tomato growers could apply 600 and 800 kg per hectare manure on the determinate and indeterminate tomato cultivars, respectively. / the National Research Foundation (NRF)

Manure-based biomass (MBB) has the potential to be a source of green energy at large coal-fired power plants and on smaller-scale combustion systems at or near confined animal feeding operations. Although MBB is a low quality fuel with an inferior heat value compared to coal and other fossil fuels, the concentration of it at large animal feeding operations can make it a viable source of fuel. Mathematical models were developed to portray the economics of co-firing and reburning coal with MBB. A base case run of the co-fire model in which a 95:5 blend of coal to low-ash MBB was burned at an existing 300-MWe coal-fired power plant was found to have an overall net present cost of $22.6 million. The most significant cost that hindered the profitability of the co-fire project was the cost of operating gas boilers for biomass dryers that were required to reduce the MBB's moisture content before transportation and combustion. However, a higher dollar value on avoided nonrenewable CO2 emissions could overrule exorbitant costs of drying and transporting the MBB to power plants. A CO2 value of $17/metric ton was found to be enough for the MBB co-fire project to reach an economic break-even point. Reburning coal with MBB to reduce NOx emissions can theoretically be more profitable than a co-fire project, due to the value of avoided NOx emissions. However, the issue of finding enough suitable low-ash biomass becomes problematic for reburn systems since the reburn fuel must supply 10 to 25% of the power plant?s heat rate in order to achieve the desired NOx level. A NOx emission value over $2500/metric ton would justify installing a MBB reburn system. A base case run of a mathematical model describing a small-scale, on-the-farm MBB combustion system that can completely incinerate high-moisture (over 90%) manure biomass was developed and completed. If all of the energy or steam produced by the MBB combustion system were to bring revenue to the animal feeding operation either by avoided fueling costs or by sales, the conceptualized MBB combustion system has the potential to be a profitable venture.

No description available.

More intensive production of hogs and cattle in Quebec during the past decade has benefited local economies, but led to over-fertilization of agricultural soils and eutrophication of waterways. Provincial ministries responded to this issue by developing regulations to control manure applications. The objective of this thesis was to determine the environmental risk associated with applying farm manure in the late fall. Spreading manure in fall after harvesting corn was a common practice for many agricultural producers in Quebec, but this period is now viewed as very risky, having more negative environmental consequences than other manure application periods. This two-year study used common diagnostic tools to compare the fertilization efficiency of solid dairy farm manure (DFM) spread in early fall, late fall and spring on a heavy clay soil used for corn production. In the first year, when DFM was the only nutrient source, there was no difference in corn yield that could be attributed to the manure application period. In the second year, each DFM plot was split and six levels of inorganic fertilizer (from 55 to 240 kg N ha-1) were applied ("Strip Split Plot") after planting. Corn tissue analysis (chlorophyll content, leaf N content at silking, cornstalk NO3 concentration) indicated that more residual N was supplied from late fall manure application than other manure application periods. Monitoring of soil NO3-N concentrations indicated that most of the NO3-N migration through the soil profile occurred after the early fall manure application. Late fall manure application appears to be the most efficient at supplying N for corn production, without deleterious environmental impacts, when DFM is applied to a heavy clay soil.

Eutrophication resulting from phosphorus (P) accumulation in water systems has been a worldwide concern for three decades. Agricultural soils are known to be an important non-point source of P in waterways. The objectives of this research are to identify agricultural management practices that reduce the risk of P loss from soils, and to investigate the underlying mechanisms of P retention and loss from soils. In the short term (4 years), dissolved P loads were not affected by tillage and were similar in corn (in a continuous corn rotation) and soybean (in a soybean/corn rotation) production systems. Soils amended with composted cattle manure had a greater P load than chemically fertilized soils. On average, 30% of the total P leached was in organic P forms, indicating that organic P compounds could also be problematic to water systems. Although manure application improved soil aggregation and thus may increase P retention by avoiding soil erosion, P loss through subsurface flow by leaching may be substantial. A simple soil test, either Mehlich-3 P or P saturation ratio can predict the P leaching potential, but water ponding on the surface of agricultural land could significantly affect the accuracy of the prediction. / The P adsorption data was fit with the Langmuir 2-surface model, which predicted that up to 90% of the native adsorbed P was distributed on the high-energy surface. Native adsorbed P in manured soils was weakly retained, as the binding strength coefficient was 50 times less in manured than chemically fertilized soil. This findings was confirmed by measuring P desorption, which showed that P desorption rate was almost 3 times greater from manured soils than from chemically fertilized soils. Manuring alters soil particle surfaces by increasing negative charge. This is the direct reason for less P adsorption and greater P desorption by manured soils. / The Langmuir 2-surface model and the adapted non-ideal competitive adsorption (MICA) model were equally good at modeling P adsorption data. However, the NICA model is more robust and can predict phosphate adsorption with changing soil solution pH. The simultaneously modeling of P adsorption and hydroxyl adsorption with the NICA model makes it a promising tool for analyzing competitive adsorption among anions in soils.

Orientador: Widsney Alves Ferreira. / Banca: Ademercio Antonio Paccola / Banca: Jorge de Lucas Junior / Banca: Rubens Carneiro Ulbanere / Banca: Roberto Maciel Cardoso / Resumo: O objetivo deste trabalho foi avaliar o desempenho econômico e a eficiência do tratamento biológico aeróbio, na redução e estabilização da matéria orgânica biodegradável, de dejetos líquidos de bovinos, visando a sua reciclagem na limpeza hidráulica das instalações dos animais ("free stall") e sua posterior utilização nas áreas de produção de forragem. O trabalho foi desenvolvido nas instalações do Sistema Intensivo de Produção de Leite (SIPL) da Embrapa - Centro Nacional de Pesquisa de Gado de Leite (CNPGL), situado no município de Coronel Pacheco, MG. Dois reatores com capacidade útil de 300 m3 cada um foram construídos para compor as unidades do processo de lodo ativado por batelada (LAB), com sistemas de aeração prolongada e intermitente. Esses reatores foram dimensionados para um tempo de detenção hidráulico de 24 dias, com diluição dos dejetos (fezes + urina) em água na proporção de 1:1. Em cada reator foi instalado um aerador-misturador submersível, regulados para períodos de aeração de nove minutos e não-aeração de 18 minutos. Uma motobomba de rotor aberto, com vazão de 60 m3/h, foi utilizada para reciclar o efluente tratado sobre os corredores dos galpões de confinamento "free stall" e promover a limpeza hidráulica dos dejetos, que retornam aos tanques de aeração por gravidade por meio de canaletas. A drenagem dos reatores foi processada por uma motobomba submersa, com vazão de 10 m3/h, conduzindo o efluente até as áreas de produção de forragem, por escoamento superficial. A caracterização dos efluentes foi realizada por meio de amostragens na entrada e no interior dos tanques de aeração, na saída da tubulação de irrigação e dos dejetos puros dos animais. Foram analisados os seguintes parâmetros: pH, temperatura, óleos e graxas, DBO total e solúvel, DQO total e solúvel, sólidos totais fixos e voláteis sólidos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was to evaluate the economic performance and efficiency of an aerobic biological treatment on the reduction and stabilization of the biodegradable organic matter of the bovine liquid manure. This effluent will be recycled in the hydraulic cleaning of the facilities (free stalls) and utilized in grass production areas. This work was done in the Embrapa - milk production intensive system (MPIS) facilities in Coronel Pacheco, state of Minas Gerais. Two reactors with capacity of 300 m3 each were built as the activated sludge sequencing batch reactor (SBR) units with prolonged and intermittent aeration. These reactors were dimensioned for a hydraulic retention time of 24 days with wastewater (manure + urine) dilution in water on the proportion of 1:1. In each reactor a submerged aerator-mixer was installed, with aeration and non-aeration periods of 9 and 18 minutes, respectively. A motor-pumping equipment with open rotor and flow of 60 m3/h was used for recycling the treated effluent on the halls of the free stall confinement facilities and to promote hydraulic cleaning of the effluent that will return to the aeration tanks by gravity conducted by channel structures. The drainage of the reactors was processed by a submerged motor-pumping equipment with flow of 10 m3/h driving the effluent to the grass production areas throughout superficial disposal. Effluent characterization was done by collecting samples on the entrance and the interior of the tanks, on the gate of the irrigation tubulation and on the bovine pure manure. There were analyzed the following parameters: pH, temperature, oils and fats, soluble and total BOD, soluble and total COD, volatile and total solids, sedimented solids, ammonia and total nitrogen, potassium, total phosphorus, magnesium and sodium. To evaluate the economic performance of the system, the costs, the annual investments... (Complete abstract click electronic access below) / Doutor