Registro Completo |
Biblioteca(s): |
Embrapa Solos. |
Data corrente: |
22/11/2002 |
Data da última atualização: |
12/11/2024 |
Autoria: |
LEMOS, P. de O. e C. |
Afiliação: |
PETEZVAL DE OLIVEIRA E CRUZ LEMOS, CNEPA/IQA. |
Título: |
Soil crusting and some factors affecting it. |
Ano de publicação: |
1956 |
Fonte/Imprenta: |
1956. |
Páginas: |
74 f. |
Idioma: |
Inglês |
Notas: |
Thesis (M.S.) - North Carolina State University, Raleigh. |
Conteúdo: |
A study was made of some factors affecting soil crusting in an attempt to expand previous work and to contribute to our knowledge of the physical conditions affecting plant growth. The interrelationships of some physical properties of natural soil crusts and the underlying soils were collected from artificial plots (concrete tanks, 4 x 4 feet) on the old Central Experiment Station Farm at Raleigh. The tanks contained the A and B horizons of five different soils: Cecil, White Store, Mayodan, Georgeville and Bladen. These were placed in the tanks five years previously. The soil properties studied were bulk density, mechanical analysis and aggregate analysis. An increase in bulk density was the main distinguishing characteristic of the crusts. Very small differences were found in mechanical composition of the crusts and underlying soils. The ability of the soil to form hard crusts was determined by the modulus of rupture. A normal procedure was described and variations simulating natural conditions, were introduced to study several factors believed to affect the tensile strength of the soil. The effect of the moisture content of soil briquets, the use of different moisture contents in briquet preparation, the influence of temperature of drying, the effect of successive cycles of wetting and drying and the influence of soil compaction by natural rainfall were investigated and discussed. The influence of certain soil characteristics on the magnitude of the modulus of rupture was also..................................... MenosA study was made of some factors affecting soil crusting in an attempt to expand previous work and to contribute to our knowledge of the physical conditions affecting plant growth. The interrelationships of some physical properties of natural soil crusts and the underlying soils were collected from artificial plots (concrete tanks, 4 x 4 feet) on the old Central Experiment Station Farm at Raleigh. The tanks contained the A and B horizons of five different soils: Cecil, White Store, Mayodan, Georgeville and Bladen. These were placed in the tanks five years previously. The soil properties studied were bulk density, mechanical analysis and aggregate analysis. An increase in bulk density was the main distinguishing characteristic of the crusts. Very small differences were found in mechanical composition of the crusts and underlying soils. The ability of the soil to form hard crusts was determined by the modulus of rupture. A normal procedure was described and variations simulating natural conditions, were introduced to study several factors believed to affect the tensile strength of the soil. The effect of the moisture content of soil briquets, the use of different moisture contents in briquet preparation, the influence of temperature of drying, the effect of successive cycles of wetting and drying and the influence of soil compaction by natural rainfall were investigated and discussed. The influence of certain soil characteristics on the magnitude of the modulus of rupture was ... Mostrar Tudo |
Thesagro: |
Briquete; Solo. |
Thesaurus Nal: |
Briquettes; Soil density. |
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
Marc: |
LEADER 02003nam a2200181 a 4500 001 1331601 005 2024-11-12 008 1956 bl uuuu m 00u1 u #d 100 1 $aLEMOS, P. de O. e C. 245 $aSoil crusting and some factors affecting it. 260 $a1956.$c1956 300 $a74 f. 500 $aThesis (M.S.) - North Carolina State University, Raleigh. 520 $aA study was made of some factors affecting soil crusting in an attempt to expand previous work and to contribute to our knowledge of the physical conditions affecting plant growth. The interrelationships of some physical properties of natural soil crusts and the underlying soils were collected from artificial plots (concrete tanks, 4 x 4 feet) on the old Central Experiment Station Farm at Raleigh. The tanks contained the A and B horizons of five different soils: Cecil, White Store, Mayodan, Georgeville and Bladen. These were placed in the tanks five years previously. The soil properties studied were bulk density, mechanical analysis and aggregate analysis. An increase in bulk density was the main distinguishing characteristic of the crusts. Very small differences were found in mechanical composition of the crusts and underlying soils. The ability of the soil to form hard crusts was determined by the modulus of rupture. A normal procedure was described and variations simulating natural conditions, were introduced to study several factors believed to affect the tensile strength of the soil. The effect of the moisture content of soil briquets, the use of different moisture contents in briquet preparation, the influence of temperature of drying, the effect of successive cycles of wetting and drying and the influence of soil compaction by natural rainfall were investigated and discussed. The influence of certain soil characteristics on the magnitude of the modulus of rupture was also..................................... 650 $aBriquettes 650 $aSoil density 650 $aBriquete 650 $aSolo
Download
Esconder MarcMostrar Marc Completo |
Registro original: |
Embrapa Solos (CNPS) |
|