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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.
31

Gesso de minério associado a fontes de fósforo na cultura do milho em sistema plantio direto no Estado de Alagoas

Pereira, Francisco Rafael da Silva [UNESP] 20 June 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-20Bitstream added on 2014-06-13T19:07:35Z : No. of bitstreams: 1 pereira_frs_me_botfca.pdf: 284602 bytes, checksum: 48757cf8488e373534df370b0344e8a0 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A hipótese desse trabalho é de que o gesso de minério, associado a fonte solúvel adequada de fósforo, aplicado superficialmente em sistema plantio direto, funciona como indutor de crescimento radicular em profundidade e influencia na produtividade do milho. O objetivo desse trabalho foi avaliar a influência do gesso de minério, associado a diferentes fontes de fósforo, sobre os atributos químicos do solo, desenvolvimento do sistema radicular e produtividade da cultura do milho sob sistema de plantio direto. O estudo foi desenvolvido na Área Experimental do Centro de Ciências Agrárias, pertencente à Universidade Federal de Alagoas. O solo onde as parcelas experimentais foram instaladas é classificado como Latossolo Amarelo Coeso distrófico. O clima, de acordo com a classificação de Koeppen do tipo As, Tropical chuvoso, com verões secos. Foi utilizado o híbrido de milho BRS 3150, cultivado em sistema de plantio direto. O delineamento estatístico foi o de blocos casualisados, com parcelas subdivididas e quatro repetições. As parcelas foram constituídas pelas fontes de fósforo (superfosfato triplo - ST, superfosfato simples - SS e sem fósforo S/P). As subparcelas foram constituídas pela presença (C/G) ou ausência (S/G) de aplicação de gesso de minério. O gesso foi aplicado em superfície 30 dias antes da semeadura do milho, que foi realizada utilizando-se semeadora pneumática de tração tratorizada, com quatro linhas individuais, espaçadas de 0,80 m, colocando-se 5 sementes por metro. Na adubação, por ocasião da semeadura, toda área experimental recebeu 30 e 120 kg ha-1 de N e K2O, na forma de uréia e cloreto de potássio, respectivamente. Nos tratamentos que receberam fósforo, foram aplicados 50 kg ha-1 de P2O5 na forma de superfosfato triplo ou superfosfato simples, dependendo do tratamento. Na adubação de cobertura foram aplicados 120 kg ha-1 de N.... / The hypothesis of this work is of that the ore gypsum, applied superficially in no-tillage system, functions as inductive of root growth in depth, thus reducing the effects of short period without rain, usual in the State of Alagoas. The objective of this work was to evaluate the influence of the ore gypsum, associate with different phosphorus sources, on the soil chemical attributes, root development and maize crop yield in no-tillage system. The study was developed in the experimental area of Centro de Ciências Agrárias, belonging to the Universidade Federal de Alagoas. The soil where the experimental plots were installed is classified as Distrofic Yellow Latossol Amarelo Coeso distrófico. The climate, in accordance with the classification of Koeppen is of the type rainy tropical, with dry summers. Was used the BRS 3150 hybrid of maize, cultivated under no-tillage system. The statistical design was of randomized blocks, in split-splot scheme, and four replications. The plots were composed by phosphorus sources (triple superphosphate - ST, simple superphosphate - SS and without phosphorus S/P). The subplots was composed by with (C/G) and without (S/G) application ore gypsum. The native vegetation was desiccated, before maize sowing, with herbicide Glyfosate using 3 L ha-1. The maize was sowed 30 days after application in surface gypsum, using seeder pneumatic of mechanics traction, with four individual lines, spaced of 0.80 m, putting 5 seeds for meter. During the sowing, all experimental area received 120 and 30 kg ha-1 of N and K2O, in form of urea and potassium chloride, respectively. In the treatments that received phosphorus, 50 kg ha-1 were applied of P2O5 in form of triple superphosphate or simple superphosphate, depending of the treatment. In covering fertilization 120 kg ha-1 of N were applied. Were evaluated on the soil the chemical attributes and on... (Complete abstract click electronic access below)
32

Phosphorus cycling in soil under wheat-pasture rotations / by Michael John McLaughlin

McLaughlin, Michael John January 1986 (has links)
2 offprints in pocket / Bibliography: leaves 184-210 / xx, 217 leaves, [1] leaf of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 1987
33

The effect of depth of placement of phosphorus fertiliser on the growth and development of field peas

Derafshi, Mohammadali H. January 1997 (has links) (PDF)
Bibliography: leaves 190-212. This thesis reports on the results of 3 glasshouse and 3 field experiments. The glasshouse experiments measure the effects of depth of placement and level of phosphorus (P) on the growth of field peas (Pisum sativum L. cv. Alma). The results of all the experiments suggest that placing P fertiliser 4-5 cm below the seed of field pea crops will be beneficial in terms of nodulation, P uptake, grain yield and grain P concentration.
34

The effects of nitrates and phosphates upon forage production of a southern Arizona desert grassland range

Freeman, Barry Newell, 1930- January 1955 (has links)
No description available.
35

The influences of environmental diversity on water-use efficiency, carbon isotope discrimination, leaf movements and nutrition of bush bean /

Raeini Sarjaz, Mahmoud. January 1997 (has links)
Effects of growth environment (E) on carbon isotope discrimination (Delta), water-use efficiency (WUE), leaf movement (LM) and nutrition of bush bean were examined. Environments in greenhouse (GR), open air (E0), perforated (E1) and non-perforated (E2) plastic covers in combination with well-watered (W0), moderately-watered (W 1), and water-stressed (W2) plants were used. Soil water content (WC), E, and E x WC interaction significantly affected Delta, WUE, dry matter (DM) and water use. WUE, photosynthetic rate, and leaf nitrogen increased; while Delta, DM, and transpiration decreased with water stress in GR, and E0. WUE in E2 either decreased or remained almost constant with decrease of WC. WUE of W0, and Delta in E2 were independent of growing environment, and WC, respectively. WUE and Delta correlations were significant in GR, E0, and E 1. LM was more paraheliotropic inside plastic coverings than those in E0. LM and pulvinus water content were affected by WC and temperature. High correlations were found between LM and the transmission of beta-rays from a beta-ray gauging system, WC, and leaf water potential. A high correlation was also found between leaf angle and 45Ca activity ratio between the extensor and flexor parts of the pulvinus. 32P uptake increased with increased root temperature, and decreased in presence of iron in the medium. Q10 values showed 32P uptake with and without the presence of iron to be mostly diffusion-controlled, but leaf movements were active processes requiring the expenditure of energy.
36

Transformation of inorganic phosphorus in manure during incubation and its effects on phosphorus availability to corn (Zea mays L.) on some soils of southern Quebec.

DuPlessis, Gaetan. January 1981 (has links)
No description available.
37

Phosphorus-silicon interactions in soils and plants

Roy, Animesh Chandra January 1969 (has links)
Typescript. / Bibliography: leaves [180]-190. / xviii, 218 l illus
38

The effect of depth of placement of phosphorus fertiliser on the growth and development of field peas / by Mohammadali H. Derafshi.

Derafshi, Mohammadali H. January 1997 (has links)
Bibliography: leaves 190-212. / xii, 212 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on the results of 3 glasshouse and 3 field experiments. The glasshouse experiments measure the effects of depth of placement and level of phosphorus (P) on the growth of field peas (Pisum sativum L. cv. Alma). The results of all the experiments suggest that placing P fertiliser 4-5 cm below the seed of field pea crops will be beneficial in terms of nodulation, P uptake, grain yield and grain P concentration. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy and Farming Systems, 1997
39

Root growth and phosphorus uptake in relation to soil structure and strength / by Rabindra Kumar Misra

Misra, Rabindra Kumar January 1986 (has links)
Bibliography: leaves 207-222 / xvi, 222 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 1987
40

The effect of depth of placement of phosphorus fertiliser on the growth and development of field peas / by Mohammadali H. Derafshi.

Derafshi, Mohammadali H. January 1997 (has links)
Bibliography: leaves 190-212. / xii, 212 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on the results of 3 glasshouse and 3 field experiments. The glasshouse experiments measure the effects of depth of placement and level of phosphorus (P) on the growth of field peas (Pisum sativum L. cv. Alma). The results of all the experiments suggest that placing P fertiliser 4-5 cm below the seed of field pea crops will be beneficial in terms of nodulation, P uptake, grain yield and grain P concentration. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy and Farming Systems, 1997

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