Submitted by Natalia de Souza Gonçalves (natalia.goncalves@ufpe.br) on 2016-09-20T14:56:03Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Alice_Silva (FINAL).pdf: 1981868 bytes, checksum: aa9f9dc8b3610b2ecf9a0894e58cfe5d (MD5) / Made available in DSpace on 2016-09-20T14:56:03Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Alice_Silva (FINAL).pdf: 1981868 bytes, checksum: aa9f9dc8b3610b2ecf9a0894e58cfe5d (MD5) Previous issue date: 2016-02-25 / FACEPE / No Brasil, há necessidade urgente de pesquisas para o desenvolvimento e aprimoramento de técnicas que viabilizem a gestão sustentável de resíduos. Essa necessidade é especialmente grave nas áreas urbanas, devido ao aumento populacional e aos padrões de consumo. A biomassa residual corresponde a aproximadamente 50% dos resíduos sólidos urbanos e é proveniente principalmente das ações de limpeza urbana, como varrição e podas de áreas públicas, de preparo e consumo de alimentos. Praticamente toda biomassa residual gerada em áreas urbanas é disposta em lixões e aterros controlados, juntamente com os demais tipos de resíduos. Uma das alternativas para a destinação sustentável da biomassa residual urbana é a produção de adubo por meio da compostagem. O presente trabalho teve como objetivo identificar a melhor proporção entre biomassa residual do serviço de limpeza urbana e os resíduos de alimentos dos restaurantes e cantinas do campus do UFPE para a produção do adubo orgânico de melhor qualidade em menor tempo. O delineamento experimental foi inteiramente casualizado, com seis tratamentos e quatro repetições, distribuídos entre proporções diferentes de material vegetal (MV) e resíduo de alimentos (RA): T1 = Material vegetal (MV) 100% + resíduos de alimentos (RA) 0% (v/v); T2 = 90% MV + 10% RA; T3 = 80% MV + 20% RA; T4 = 70% MV + 30% RA; T5 = 60% MV + 40% RA; T6 = 50% MV + 50% RA. Foram realizados testes de compostagem em pilhas de 50 kg de material vegetal e resíduo de alimentos, por um período de 120 dias. Durante o período de compostagem, foram realizadas análises das concentrações de nitrogênio, fósforo, potássio e Carbono orgânico total, bem como monitoramento de pH, temperatura e umidade das pilhas. O tratamento T6 apresentou qualidade superior entre os demais tratamentos, em termos nutricionais. O T3 não apresentou diferenças significativas no tempo de estabilização comparado aos tratamentos T4, T5 e T6, tendo atingido relação C/N de 18/1 em apenas 30 dias. Esses resultados sugerem que, com uma proporção de 20% RA e 80 de MV em apenas 30 dias de estabilização, o composto orgânico estaria pronto para uso, o que poderia otimizar o uso de mão de obra e diminuir a necessidade de água para umidecer as pilhas, além de finalizar o processo mais rapidamente. / In Brazil, there is an urgent need for research to the development and improvement of techniques that enable the sustainable management of waste. This need is particularly acute in urban areas, due to population growth and consumption patterns. The residual biomass corresponds to approximately 50% of municipal solid waste and comes mainly from urban cleaning activities, such as public areas sweeping and pruning, preparation and consumption of food. Virtually all biomass waste generated in urban areas is disposed in open dumps and controlled landfills along with other types of waste. One alternative for sustainable biomass disposal of urban waste is the production of manure by composting. This study aimed to identify the best ratio between residual biomass of urban sanitation services and food waste from campus of UFPE restaurants and canteens, for the production of organic fertilizer better quality in less time. The experimental design was completely selected, with six treatments and four replications, distributed among different proportions of plant material (PM) and waste food (WF): T1 = plant material (PM) 100% + waste food (WF) 0% (v / v); T2 PM = 90% PM + 10% WF; T3 = 80% PM + 20% WF; T4 = 70% PM + 30% WF; T5 = 60% PM + 40% WF; T6 = 50% MV+ 50% WF. Composting tests were performed on batteries 50 kg of plant material and residual food for a period of 120 days. During the composting period, analyzes were made of concentrations of nitrogen, phosphorus, potassium and total organic carbon and pH monitoring, temperature and humidity of the batteries. The T6 treatment showed superior quality among other treatments, nutritionally. T3 no significant differences in the stabilization time compared to treatment T4, T5 and T6, reaching C / N ratio of 18/1 in just 30 days. These results suggest that, with a ratio of 20% of WF and 80 of PM in just 30 days of stabilization, the organic compound would be ready for use, which could optimize the use of manpower and reduce the need for water to humidify the batteries, and complete the process more quickly.

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The overuse of agrochemicals by arable crop farmers in Guyana is of increasing concern. But the literature reveals a paucity of information concerning the reasons for farmers‟ persistence of this inappropriate practice. No previous study has been conducted using a structured format to reveal the scope or reasons for farmers‟ sustained overuse of these chemicals. This research adopted an original structured-type approach, suitable for unearthing and explaining the reasons for this phenomenon. The study was theoretically and analytically guided by the theory of practices and critical realist theory respectively, to identify the prevalence, intensity and significant factors of farmer‟s pesticide and fertiliser overuse, but more importantly to elucidate reasons for overuse and formulate relevant recommendations. This investigation utilised a mixed methods strategy of complementary quantitative and qualitative techniques; comprising analysis of data from 229 farm unit surveys and 38 farmer and 19 key informant interviews, respectively. Quantitative analysis, conducted via SPSS software using tables and regression, revealed widespread prevalence of both pesticide and fertiliser overuse among farmers. The overuse consisted of high frequencies and concentrations of the chemicals. The study notes the factors which were significantly associated with overuse including farmers‟ age, education level, area cultivated, land tenure status and the „source-type‟ of information they accessed. However, qualitative analysis, utilising a grounded-theory approach with the aid of NVivo software, demonstrated that unlike the suggestions by other studies, the reasons for farmers‟ overuse were not the single factors which showed statistical significance for overuse practices. On the contrary, this study revealed original findings, which indicated that the reasons for farmers‟ overuse practices were embedded within an intricate network of contingent, support and contextual factors. These explained both the instigation and continuance of agrochemical overuse by farmers. Overall the findings emphasise the need for policy redress, especially regarding the mandate and conduct of farmer-training regarding chemical use, and the regulatory enforcement of appropriate agrochemical use. Understanding the reasons for farmers‟ inappropriate practices revealed new insight into the interpretation of these practices; as consequences of policy deficiency instead of farmer delinquency. Thus, the implications provided to address this problem of farmers‟ agrochemical overuse presented a new orientation to the type of suggestions previously suggested in other studies. The proposals indicated by this study for a targeted resolution of overuse in arable farmers of Guyana are more policy-oriented than farmer-targeted, since this study revealed that farmers‟ overuse behaviour is largely a response to policy-influenced support and contextual factors.

<p>Starter fertilizer applied with or near the seed at planting often enhances early season maize growth (<i>Zea mays</i> L.) but does not always result in higher grain yield. Other responses to starter fertilizer, such as reduced thermal time to reach silking, which suggests accelerated plant development, have been documented. The objective of this study was to examine the relationship between dry matter production and accelerated plant development with respect to 5x5 cm starter (ST) and in-furrow popup (PU) fertilizer. A field experiment was conducted in 2016 with three at-planting treatments consisting of one single rate and formulation of ST (53 N and 21 P kg ha^-1) or PU (4 N and 6 P kg ha^-1), and an untreated control. In 2018, the study included four additional site-years with treatments consisting of an intermediate (ST) or high (STH) starter fertilizer rate, and an untreated control. For ST treatments, depending on location, nitrogen (N) and phosphorus (P) fertilizer rates ranged between 26-28 and 6-10 kg ha^-1, respectively, and for STH treatments N and P fertilizer rates ranged between 47-56 and 12-20 kg ha^-1, respectively. In 2016, as new leaf collars appeared, dry matter increased exponentially, but at an equal number of leaf collars ST and PU had similar dry matter as the control. In 2018, dry matter for ST, STH, and control was also similar when normalized for leaf collar number at each site. Overall, these results suggest that enhanced dry matter at a given point in time from ST, STH, or PU was a function of accelerated leaf development as opposed to physically more robust plants of the same leaf collar number. Grain yield was unaffected by ST, STH, or PU treatments at any site-year.</p> <p>Methods used to study roots in crop fields have included extracting soil cores, excavating entire root systems, using radioactive and non-radioactive chemical tracers, or using mini-rhizotrons. However, due to the intensive nature, level of difficulty, and cost associated with these methods, their use in crop fields has been minimal. We developed an alternative method to quantify maize rooting density over time. The method involved perforated cylinders installed vertically into the soil at different distances from the row, which made roots growing into the cylinder voids visible from the soil surface and possible to count [root number density (RND)] at different depths using a video recording device (1m-long borescope). The objective of this study was to determine if the cylinder method could quantify rooting density throughout the growing season (V3, ~V7, and R2-R3) similar to the more intensive soil core method, compared in two starter fertilizer trials [continuous maize (M/M) and maize/soybean (M/S) rotation]. Cylinders were constructed with perforated (49% voids) polypropylene resin to an inside diameter of 2.58 cm and a length of 30 cm. Cylinders were painted with red and green alternating markings (5 cm) on the outside and inside walls to visually aid in identifying depth from the soil surface. After plants emerged, cylinders were inserted vertically into the soil after drilling a 3.5 cm diameter borehole. Ten perforated cylinders were installed in a parallel line 13 or 25 cm away from, and on both sides of, the planted row. Soil cores were also collected at the same relative locations for conducting root extractions and subsequent calculation of length density (RLD). At V3, methods frequently resulted in the same significant (<i>p≤</i>0.10) or insignificant (<i>p></i>0.10) main and interaction effects in both fields, whereas at ~V7 and R2-R3, there were several instances where the cylinder method failed to detect the same effects as the soil core method. At times both the cylinder method and the soil core method detected significant main or interaction effects, but the direction of the effect was opposite.</p> <p>In-furrow biological (BIO) and plant growth regulator (PGR) products, otherwise known as biostimulants, are becoming increasingly available in the commercial maize market. The objective of this study was to compare the effects of several commercially available in-furrow biostimulant products on maize growth and development, nutrient uptake, and grain yield to starter fertilizer in large-plot field trials. The study was conducted across five locations in 2016, and three locations each in 2017 and 2018 at Purdue University research farms. At each location, treatments consisted of four different BIO or PGR products plus starter fertilizer, starter fertilizer only, and an untreated control. Compared to the control, starter-only increased grain yield at 7 of 8 site-years in 2016 and 2018 ranging from 125 to 753 kg ha^-1, depending on location, but no increase was found at any of the 3 locations in 2017. Grain yield was increased (3 of 11 site-years) or decreased (2 of 11 site-years) by some of the BIO or PGR products, but in 6 of 11 site-years none of the products affected yield compared to starter-only.</p>

In North Dakota, adoption of conservation tillage practices has resulted in an accumulation of crop residue remaining on the soil surface. North Dakota producers receive a nitrogen credit for long-term no-till but due to previous crop residue this credit may not be realistic for providing partial nutrient needs to subsequent crops in a cool environment with a short growing season. Our objectives were to evaluate the N mineralization potential of common crop residues to determine whether crop residue accumulation in no-till systems can provide sufficient nitrogen quantities needed for subsequent crops. Three lab incubation studies were conducted to provide N mineralization insights for individual crop residues, crop residues over several simulated growing seasons, and crop residue in diversified cropping systems. Differences in soil texture, surface application versus incorporation of residue, freeze and thaw cycles and combinations of residues were all factors examined. Results indicated that crop residue decomposition and N release from the residue treatments generally immobilized N but were not significantly different from the bare soil for nearly all studies. The only exception observed was for the forage radish cover crop which showed the potential to improve soil N mineralization in select three-year rotations. Findings of these studies show that most wide C:N ratio crop residues will immobilize soil N in a no-till system under ideal conditions (i.e. moisture, temperature, and residue particle size). These findings suggestion that a fertilizer N credits may require reevaluation and take into consideration soil moisture with validated data to support the fertilizer N credit.

Alfalfa has long been recognized as an outstanding hay plant in term. of both yield and feeding value. It is high in digestible protein, minerals, and vitamins. Because of its long life it can be economically produced. It is of exceptional value in maintaining soil fertility by helping to control erosion, by improving the physical condition of the soil, and by accumulating large amount of nitrogen.

The influence of agronomic practices on forage production and chemical composition of grass-legume pasture mixture was studied at the Utah State University Dairy Farm, North Logan, Utah, during spring and summer, 1970. The soil is a well-drained Millville silt loam that has about a 1 percent slope . It is high in potash, phosphorus, and lime, having a pH of 7.9. Analysis of the clipping management showed that the early spring clipping decreased the yield of forage. The losses in total yield due to spring clipping were approximately four to five times the yields received in early spring clipping. The grasses were affected more than the legumes. The yields of dry forage increased with the increase in fertilizer rates from 0 through 300 pounds of nitrogen per acre. There was no advantage to splitting the nitrogen fertilizer of 300 pounds per acre into three applications. Most of the effects of spring clipp1ng and nitrogen fertilization were re fleeted in the first summer harvest. The plots fertilized with nitrogen produced a higher yield and nitrate content than the check plots. Legumes were higher in nitrate on the unfertilized plots than the grasses, but lower on the fertilized plots.

Sweet corn is rapidly becoming an important cash crop in many of the irrigated regions of the intermountain West. The lacome from this crop is relatively small in comparison to that from other major agricultural products; however, sweet corn production has a definite place in the economy of the region. One of the factors limiting increasing acreage of sweet corn in many areas is low yields. Yields have been increased naterially in recent years with the development of hybrid varieties, superior to the standard varieties previously used. Better cultural practices are improving yields, but much remains to be done in this phase of the work. Plant growth is affected by many complex factors, two of which are soil fertility and moisture. A considerable number of investigations have been carried out where either fertility or moisture effects have been studied independently. Four studies have been made where the two factors have been studied jointly in the same experiment. Recent trends in experimental research tend to emphasize the value of studying two or more factors at the same time, thereby making it possible to study interaction that otherwise would not have been observed. This study was an attempt to determine the effects of various soil fertility and soil moisture levels on the yield of sweet corn. These factors were studied simultaneously. By studying the relationships that exist between moisture and fertility, it is theoretically possible to arrive at the optimum level for both factors, thus obtaining maximum yields. Studies leading to the data reported in this paper were conducted on Nibley silty clay loam at the Utah State Agricultural College Forage Crops Experimental Farm near Nibley, Utah.

The practice of applying fertilizers to the soil by adding the liquid form to the irrigation water is increasing in popularity. There are several advantages maintained for such a method of application. Some of the advantages are: (A) Ease of application (B) No special equipment is required for application. (C) The fertilizer can be applied at any stage of plant growth without physical disturbance of the plant. (D) Penetration into the root zone may be greater than the dry fertilizers. Considerable phosphate fertilizer is used on soils of irrigated regions. If the behavior of liquid phosphoric acid after its incorporation with soil is such that it penetrates into the root zone and is otherwise as efficient as dry phosphate fertilizers in inducing favorable plant response, then it would seem practical to utilize the other advantages offered by applying the fertilizer in irrigation water. Commercial phosphoric acid (52% available P2O5) is produced by applying an excess of sulfuric acid to ground rock phosphate. This phosphoric acid is usually applied to an additional amount of phosphate rock to make concentrated superphosphate. A given quantity of phosphoric acid can yield more available phosphorus by applying it to rock phosphate than by using it directly as a fertilizer. Because of its potential value in producing concentrated superphosphate commercial phosphoric acid has been used very little as a fertilizer. There is insufficient research in which the comparative value of the acid as a fertilizer has been investigated the purpose of the studies reported in this paper are, to compare: (A) the value of commercial phosphoric acid and concentrated superphosphate as fertilizers when applied in equivalent amounts and, (B) the different methods of application and dilution of the phosphoric acid.