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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Fósforo em solo tratado com biossólido e cultivado com milho

Souza, Wilson José Oliveira de [UNESP] 20 February 2004 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-20Bitstream added on 2014-06-13T19:04:52Z : No. of bitstreams: 1 souza_wjo_dr_jabo.pdf: 436212 bytes, checksum: 09da9fc53726e0e85a186a79d29b73d2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A área experimental foi instalada na Fazenda de Ensino e Pesquisa da Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, SP, localizada a uma altitude de 610m e com as seguintes coordenadas geográficas: 21°15'22 S e 48°15'18 W. O clima é do tipo Cwa, segundo a classificação de Köppen, isto é, subtropical, temperado, seco no inverno, com temperatura média máxima superior a 22°C. O experimento foi instalado com o objetivo de estudar o comportamento de diferentes doses de biossólidos aplicadas, comparadas à fertilização mineral, sobre formas de fósforo no solo, bem como distribuição do nutriente no perfil até a profundidade de 0,60m. Utilizou-se a cultura do milho nos anos agrícolas 1997/1998, 1998/1999 e 1999/2000, utilizando-se um solo latossolo vermelho distroférrico, em delineamento de blocos ao acaso, com quatro tratamentos e cinco repetições. Os tratamentos utilizados foram: sem qualquer tipo de fertilização (no ano agrícola 1997/98) e apenas com fertilização mineral (nos anos subseqüentes) (T); aplicação de 2,5 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L1), aplicação de 5,0 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L2), aplicação de 10 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L3). Avaliou-se a distribuição do P total e P das frações substâncias humicas (P-SH), ácido fúlvico (P-AF), acido humico (P-AH) e humina (P-HN), P inorgânico, P orgânico, P Total(i+o), P extraível no perfil até a profundidade de 0,60m, bem como suas inter-relações... / This work was carried out in Experimental and Research Farm of FCAV - UNESP, Jaboticabal county, São Paulo State, located at 610m altitude and geographic coordinates: 21°15'22 S and 48°15'18 W. The climate is Cwa by Kopen classification, sub tropical, temperate dry winter, with average maximum temperature of 22°C. The experiment was carried out with the objective to study the comportment of different biossolid ratio applications, compared with mineral fertilization, on P forms and distribution in soil layers from surface to 0,60m. The Maize was utilized at tree years (1997/98, 1998/99 and 1999/00) using an Oxisol in randomized blocks, with four treatments and five replications, cultivating maize without mineral fertilization (1997/98) and only mineral fertilization in the following years (T); 2.5 t biosolid ha-1 (dry basis) (L1), 5 t biosolid ha-1 (dry basis) (L2), 10 t biosolid ha-1 (dry basis) (L3). The treatments with biosolid was amended with mineral fertilizer (P and K) whenever necessary. The area was prepared and biossolid was applied and then incorporated at 0,05-0,10m. Phosphorus in nitric percloric acid (PNP), humic substances fractions (P-SH), fulvic acid (P-AF), humic acid (P-AH), humin (P-HN), inorganic phosphorus (Pi), total phosphorus (total P), organic phosphorus (Po) and resin phosphorus (P res) was evaluated in 0-0.05m, 0.05-0.10m, 0.10-0.20m, 0.20-0.40m and 0.40-0.60m layers. Phosphatase activity was evaluated at 0-0.05m and 0.05-0.10m. The data showed that the application of 5 t ha-1 biosolid was the best treatment, considering the amound of total P and labile fractions (P-SH) and less labile fractions (P-AF) in the upper layers. Dose that showed the best total P and P-HN contents is 7 t ha-1; non labile P forms (P-AH) was detected bellow the 0.20m layers including when mineral fertilizer was applied... (Complete abstract, click eletronic address below)
12

Fósforo em solo tratado com biossólido e cultivado com milho /

Souza, Wilson José Oliveira de. January 2004 (has links)
Resumo: A área experimental foi instalada na Fazenda de Ensino e Pesquisa da Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, SP, localizada a uma altitude de 610m e com as seguintes coordenadas geográficas: 21°15'22" S e 48°15'18" W. O clima é do tipo Cwa, segundo a classificação de Köppen, isto é, subtropical, temperado, seco no inverno, com temperatura média máxima superior a 22°C. O experimento foi instalado com o objetivo de estudar o comportamento de diferentes doses de biossólidos aplicadas, comparadas à fertilização mineral, sobre formas de fósforo no solo, bem como distribuição do nutriente no perfil até a profundidade de 0,60m. Utilizou-se a cultura do milho nos anos agrícolas 1997/1998, 1998/1999 e 1999/2000, utilizando-se um solo latossolo vermelho distroférrico, em delineamento de blocos ao acaso, com quatro tratamentos e cinco repetições. Os tratamentos utilizados foram: sem qualquer tipo de fertilização (no ano agrícola 1997/98) e apenas com fertilização mineral (nos anos subseqüentes) (T); aplicação de 2,5 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L1), aplicação de 5,0 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L2), aplicação de 10 t ha-1 de biossólido (base seca) e complementação mineral de P e K, quando necessário (L3). Avaliou-se a distribuição do P total e P das frações substâncias humicas (P-SH), ácido fúlvico (P-AF), acido humico (P-AH) e humina (P-HN), P inorgânico, P orgânico, P Total(i+o), P extraível no perfil até a profundidade de 0,60m, bem como suas inter-relações... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work was carried out in Experimental and Research Farm of FCAV - UNESP, Jaboticabal county, São Paulo State, located at 610m altitude and geographic coordinates: 21°15'22" S and 48°15'18" W. The climate is Cwa by Kopen classification, sub tropical, temperate dry winter, with average maximum temperature of 22°C. The experiment was carried out with the objective to study the comportment of different biossolid ratio applications, compared with mineral fertilization, on P forms and distribution in soil layers from surface to 0,60m. The Maize was utilized at tree years (1997/98, 1998/99 and 1999/00) using an Oxisol in randomized blocks, with four treatments and five replications, cultivating maize without mineral fertilization (1997/98) and only mineral fertilization in the following years (T); 2.5 t biosolid ha-1 (dry basis) (L1), 5 t biosolid ha-1 (dry basis) (L2), 10 t biosolid ha-1 (dry basis) (L3). The treatments with biosolid was amended with mineral fertilizer (P and K) whenever necessary. The area was prepared and biossolid was applied and then incorporated at 0,05-0,10m. Phosphorus in nitric percloric acid (PNP), humic substances fractions (P-SH), fulvic acid (P-AF), humic acid (P-AH), humin (P-HN), inorganic phosphorus (Pi), total phosphorus (total P), organic phosphorus (Po) and resin phosphorus (P res) was evaluated in 0-0.05m, 0.05-0.10m, 0.10-0.20m, 0.20-0.40m and 0.40-0.60m layers. Phosphatase activity was evaluated at 0-0.05m and 0.05-0.10m. The data showed that the application of 5 t ha-1 biosolid was the best treatment, considering the amound of total P and labile fractions (P-SH) and less labile fractions (P-AF) in the upper layers. Dose that showed the best total P and P-HN contents is 7 t ha-1; non labile P forms (P-AH) was detected bellow the 0.20m layers including when mineral fertilizer was applied... (Complete abstract, click eletronic address below) / Orientador: Wanderley José de Melo / Coorientador: Marcos Omir Marques / Banca: Mara Cristina Pessôa da Cruz / Banca: Takashi Muraoka / Banca: Ronaldo Severiano Berton / Banca: José Carlos Barbosa / Doutor
13

Effect on Climate Change on Maize Production in Zambia

Ngoma, Justine January 2008 (has links)
<p>Maize is one of the crops that is grown by most farmers in Zambia being the staple food for the majority of Zambians. However, despite the crop being so important, its production is dependent on climatic conditions. This means that any change in climate can affect the production either negatively or positively. This research therefore, focused on determining how the change in temperature and rainfall affect maize production on the Copper belt, Eastern, Lusaka and Southern provinces of Zambia and investigate the main adaptation measures implemented by both the government and non-governmental sectors. Also, assess through the review of National Agricultural Policy and action plans, how the government has documented issues of climate change. In order to obtain the needed data, interviews were conducted with different officials from both the government and non-governmental sectors. However, from the estimate of the impact of temperature and rainfall on maize production, the results did not show with any significance that either temperature or rainfall has effect on maize production. In fact, it was found that quantifying the effects of climate change on maize production is not easy due to difficulties in quantifying other factors that may also have large impact on maize production. It was therefore, not possible to conclude whether or to what extent climate change has effects on maize production. However from the interviews conducted, it was found that both the government and non-governmental sectors have introduced different activities in their programmes to ensure that farmers are food secure, though the ministry of agriculture has no policy document on how to handle the problem of climate change to address different issues of the sector. In fact, most offices in the ministry do not have much documented information on climate change which could also be seen from the review of National Agricultural Policy and action plans where climate change issue has not been emphasized. Though both the Government and non-governmental sectors have implemented some adaptation measures, it cannot easily be concluded whether the implemented measures are adequate or not due to the fact that we are not sure of the expected effects in different parts of the country. Nevertheless, to enhance food security with or without adverse effects of climate change on maize production, it was recommended that members of staff at all levels under MACO should be trained in the area of climate change for them to have a wider understanding of the issue and work responsively and that much research should be done to open up the mind of the people and help policy makers make effective plans.</p>
14

Effect on Climate Change on Maize Production in Zambia

Ngoma, Justine January 2008 (has links)
Maize is one of the crops that is grown by most farmers in Zambia being the staple food for the majority of Zambians. However, despite the crop being so important, its production is dependent on climatic conditions. This means that any change in climate can affect the production either negatively or positively. This research therefore, focused on determining how the change in temperature and rainfall affect maize production on the Copper belt, Eastern, Lusaka and Southern provinces of Zambia and investigate the main adaptation measures implemented by both the government and non-governmental sectors. Also, assess through the review of National Agricultural Policy and action plans, how the government has documented issues of climate change. In order to obtain the needed data, interviews were conducted with different officials from both the government and non-governmental sectors. However, from the estimate of the impact of temperature and rainfall on maize production, the results did not show with any significance that either temperature or rainfall has effect on maize production. In fact, it was found that quantifying the effects of climate change on maize production is not easy due to difficulties in quantifying other factors that may also have large impact on maize production. It was therefore, not possible to conclude whether or to what extent climate change has effects on maize production. However from the interviews conducted, it was found that both the government and non-governmental sectors have introduced different activities in their programmes to ensure that farmers are food secure, though the ministry of agriculture has no policy document on how to handle the problem of climate change to address different issues of the sector. In fact, most offices in the ministry do not have much documented information on climate change which could also be seen from the review of National Agricultural Policy and action plans where climate change issue has not been emphasized. Though both the Government and non-governmental sectors have implemented some adaptation measures, it cannot easily be concluded whether the implemented measures are adequate or not due to the fact that we are not sure of the expected effects in different parts of the country. Nevertheless, to enhance food security with or without adverse effects of climate change on maize production, it was recommended that members of staff at all levels under MACO should be trained in the area of climate change for them to have a wider understanding of the issue and work responsively and that much research should be done to open up the mind of the people and help policy makers make effective plans.
15

Determinants of the supply-side fragmentation of maize storage in the North Western Free State production area / Mathys Johannes Nicolaas van der Merwe.

Van der Merwe, Mathys Johannes Nicolaas January 2012 (has links)
For decades commercial silos in South Africa was the only option in which maize could be delivered and sold. After deregulation in the late 1990s commercial silo owners came to face the challenge of alternative storage solutions and loss of market share. The reasons are determined for a shift from commercial storage to on-farm storage. The extent to which on-farm storage will change the current maize storage industry is discussed. The study commences by describing the birth and rapid growth of maize production in South Africa. Soon after maize became a major role-player in the export industry, it was characterised by regulation. The rationale why the market was regulated and how it influenced grain storage is explained. The deregulation process and the objectives of the new Marketing of Agricultural Products Act, No. 47 of 1996, are paraphrased. In the deregulated market, current and future, maize prices are determined by supply and demand. Incentives for storage emerged and cheaper substitutes with various other advantages began to propose alternative storage solutions to farmers. These concurrences of circumstances then lead to fragmentation of grain storage in South Africa. As a relatively young free market, the maize value chain is described to illustrate the position of each role-player in relation to the silo owner. The new price determination factors, price movement rationale and the use of market instruments are subsequently explained. Naturally, a critical assessment of the main different storage solutions available for farmers, are investigated next. Fragmentation is defined and discussed in terms of market equilibrium. A comparison is drawn between the South African and the Australian as well as the US maize storage industry. The empirical research was conducted on two sample groups of farmers in the Free State. The first group is farmers that already make use of an on-farm storage facility. The second group is farmers that annually produce more than 5000 tons of maize and currently do not make use of an on-farm storage facility. Seven important reasons for an on-farm storage facility are determined in the literature study as well as a qualitative study that preceded the quantitative study. Respondents are asked to rank the reasons in order of, in their opinion, importance. A generalized profile of a respondent in each sample group was compiled. Hereafter the outcome of the reasons ranked by both sample groups is discussed. It appeared that Flexible Marketing Option was the most important reason for farmers that already make use of on-farm storage. Farmers did not indicate that Handling and Storage costs are the most important reason why they would invest in an on-farm storage facility. Correlations are drawn between groups and the significance of differences is determined. It is concluded that on-farm storage is sustainable and there will be an increase of the phenomenon over the next three years. Recommendations are given for commercial silo owners to regain market share. Costs analyses and effective cost management along with the promotion that marketing options are just as flexible within commercial silos, as it is outside, are some of the recommendations made. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
16

Determinants of the supply-side fragmentation of maize storage in the North Western Free State production area / Mathys Johannes Nicolaas van der Merwe.

Van der Merwe, Mathys Johannes Nicolaas January 2012 (has links)
For decades commercial silos in South Africa was the only option in which maize could be delivered and sold. After deregulation in the late 1990s commercial silo owners came to face the challenge of alternative storage solutions and loss of market share. The reasons are determined for a shift from commercial storage to on-farm storage. The extent to which on-farm storage will change the current maize storage industry is discussed. The study commences by describing the birth and rapid growth of maize production in South Africa. Soon after maize became a major role-player in the export industry, it was characterised by regulation. The rationale why the market was regulated and how it influenced grain storage is explained. The deregulation process and the objectives of the new Marketing of Agricultural Products Act, No. 47 of 1996, are paraphrased. In the deregulated market, current and future, maize prices are determined by supply and demand. Incentives for storage emerged and cheaper substitutes with various other advantages began to propose alternative storage solutions to farmers. These concurrences of circumstances then lead to fragmentation of grain storage in South Africa. As a relatively young free market, the maize value chain is described to illustrate the position of each role-player in relation to the silo owner. The new price determination factors, price movement rationale and the use of market instruments are subsequently explained. Naturally, a critical assessment of the main different storage solutions available for farmers, are investigated next. Fragmentation is defined and discussed in terms of market equilibrium. A comparison is drawn between the South African and the Australian as well as the US maize storage industry. The empirical research was conducted on two sample groups of farmers in the Free State. The first group is farmers that already make use of an on-farm storage facility. The second group is farmers that annually produce more than 5000 tons of maize and currently do not make use of an on-farm storage facility. Seven important reasons for an on-farm storage facility are determined in the literature study as well as a qualitative study that preceded the quantitative study. Respondents are asked to rank the reasons in order of, in their opinion, importance. A generalized profile of a respondent in each sample group was compiled. Hereafter the outcome of the reasons ranked by both sample groups is discussed. It appeared that Flexible Marketing Option was the most important reason for farmers that already make use of on-farm storage. Farmers did not indicate that Handling and Storage costs are the most important reason why they would invest in an on-farm storage facility. Correlations are drawn between groups and the significance of differences is determined. It is concluded that on-farm storage is sustainable and there will be an increase of the phenomenon over the next three years. Recommendations are given for commercial silo owners to regain market share. Costs analyses and effective cost management along with the promotion that marketing options are just as flexible within commercial silos, as it is outside, are some of the recommendations made. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
17

The economic impact of adult mortality and morbidity on smallholder farm households in Malawi [electronic resource]

Simwaka, Kisukyabo. January 2011 (has links)
This thesis comprises three essays on “The Economic impact of adult mortality and morbidity on smallholder farm households in Malawi.” The first essay estimates the levels of technical efficiency of AIDS-affected and non-affected smallholder farm households, and examines the technical efficiency differentials. The study uses time-varying and timeinvariant inefficiency models of production. The results show that among both female and male headed households, for both affected and non-affected households, fertilizer and seeds are the only variables that contribute significantly towards technical efficiency. The mean efficiency levels of affected and non-affected households are statistically not different. The second essay examines the maize production differentials between AIDS-affected and nonaffected farm households using the difference in difference estimation method. The results show that, for both affected and non-affected households, the mean maize production levels are higher during 2006/07 compared to 2004/05 However, the difference between the mean maize production levels of affected and non-affected households over the 2004/05 and 2006/07 period is not statistically significant. The third essay examines the coping strategies used by households facing food security problems. The results from the multinomial logistic model show that during 2004/05 and 2006/07, the most dominant coping strategy used by both AIDS-affected and non-affected households facing food security problems, is buying food from market. This is followed by casual labour, obtaining food from relatives and friends, eating unripe maize before harvest, and irrigation farming. The results from logistic discriminant analysis function indicate that, for all households, ordinary coping strategies are dominant among food-insecure households with a total score of close to 80 percent, much higher than survival strategies at around 20 percent during 2004/05. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.
18

Assessment of agro-ecosystem sustainability across varying scales in South Africa.

Walker, Nicholas James. January 2005 (has links)
Maize production plays an important socio-economic role in rural communities of the Highveld region of South Africa, yet it is becoming increasingly difficult to produce maize economically with current agricultural policy conditions and existing management systems. This has direct socio-economic impacts for both commercial farmer and small-scale farmer. Sustainable commercial maize production is not only a question of yields, but also of protection of the environmental resource base, social welfare, and the livelihoods of farmers per se as well as the surrounding rural and urban communities. Sustainability for the small-scale farmer, on the other hand raises questions of equity, economic viability and household food security. Therefore, information is required to ascertain whether an existing agro-ecosystem can be identified as sustainable, and what facets of that system make it sustainable or unsustainable. To begin to answer these key questions it is important to state, and to some extent attempt to standardise, the definitions of agricultural sustainability. Agro-ecosystem sustainability with regard to maize production was assessed at the regional scale of the Highveld of South Africa as well as at, the Quaternary Catchment scale and the smallholder farm scale. Von Wiren-Lehr's (2001) goal orientated system was considered an appropriate and practical system by which agro-ecosystem sustainability across a range of scales could be investigated. At the regional scale, optimum management strategies for each of the 497 Quaternary Catchments in the Highveld region were devised, based on present climatic conditions and using an index which was based on mean yields and yield variability. Economic returns and their impact on sustainability were then also assessed under plausible future climate scenarios. At the Quaternary Catchment scales optimum management strategies were ascertained by using a sustainability index. These strategies were then modelled under present and plausible future climate scenarios. The results from the sustainability modelling showed that a maize crop will benefit, especially with respect to mean grain yields, from an effective doubling of atmospheric CO2 concentrations. However, this benefit can be counteracted when there is a concurrent increase in temperature, particularly of 2°C or more. At the smallholder scale, a range of management options was assessed. These options included several types of tillage practices in combination with applications of either inorganic fertiliser or manure. The management strategies were modelled under present climate conditions and under plausible climate change scenarios for southern Africa. The conventional tillage type (disc) was ranked highest under most of the climatic conditions modelled, including present climate conditions. This was in contrast to actual yields from smallholder farmers (-1 ha field size) in the Potshini area, near Bergville in the KwaZuluNatal province of South Africa, who have experienced an increase in yield when conservation tillage practices have been used on their land (Smith et al., 2004). The sustainability of agro-ecosystems depends on the maintenance of the economic, biophysical and social components that make up the system (Belcher et al., 2004). The modelling performed for the Highveld region built on previous work and for the first time incorporated daily temperatures and ISCW soil information into CERES-Maize. The intention was to incorporate other agro-ecosystem functions, as well as yield, into the sustainability assessment. Only limited research has previously been carried out in South Africa with respect to modelling smallholder agro-ecosystems and sustainability. This research sought to model the smallholder system along with the impacts that climate change would have on sustainability and associated food security. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
19

Impact of Amendments on Soil Properties and Agronomic Productivity in Guyana

Moonilall, Nall Inshan 26 August 2015 (has links)
No description available.
20

Climate change awareness: a case study of small scale maize farmers in Mpumalanga province, South Africa

Oduniyi, Oluwaseun Samuel 07 1900 (has links)
This study was conducted in the Nkangala district, in the province of Mpumalanga in South Africa. This province remains the largest forestry production region in South Africa. The majority of people living in Mpumalanga are farmers and they have contributed immensely to promote food security. The objective of the study was to determine the level of climate change awareness among small scale maize producers in Mpumalanga province. Random sampling techniques was used to select two hundred and fifty one (251) farmers to be interviewed. A pre-tested questionnaire was administered to maize farmers, focusing on matters relating to climate change awareness in maize production. Data was captured and analysed using software package for social science (SPSS version 20 of 2012). Descriptive statistics were applied to analyse and describe the data. Logistic regression analysis followed to demonstrate the significance of the independent variables on climate change awareness. The results of the analysis indicated that the information received and the size of the farm had an impact on climate change awareness in the area of study. It was therefore recommended that the majority of farmers in Mpumalanga needed to be made aware of climate change in order to assist them to build the adaptive capacity, increase resilience and reduce vulnerability. Information on climate change awareness should be disseminated well to ensure that it will attract the attention of the farmers / Agriculture and  Animal Health / M.Sc. (Agriculture)

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