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Book Chapter 1999

Autor: Westerhof, R Vilela, L Ayarza, Miguel Angel Zech, W.

The effect of land use on the availability of soil nitrogen (N) was studied by separating total soil N into one labile and one stable fraction by oxidation and extraction of labile N with potassium permanganate. The nitrogen management index (NMI) was calculated according to Blair et al. (1995) f...

Enlace original: https://cgspace.cgiar.org/handle/10568/55133

Investigación en Agricultura
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Westerhof, R ,  Vilela, L ,  Ayarza, Miguel Angel ,  Zech, W. ,  [Labile N and the nitrogen management index of oxisols in the Brazilian cerrados] ,  Labile N and the nitrogen management index of oxisols in the Brazilian cerrados
Book Chapter 1999

Autor: Westerhof, R Buurman, P Griethuysen, C. van Ayarza, Miguel Angel Vilela, L Zech, W.

In the Cerrados, a large savanna region in Brazil, the effects of different land use on aggregation in Oxisols were studied, using laser diffraction grain-size analyses. The topsoil of plowed systems had significantly fewer macroaggregates (194-2000 micro m) and a significantly larger fraction of...

Enlace original: https://cgspace.cgiar.org/handle/10568/55128

Investigación en Agricultura
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Westerhof, R ,  Buurman, P ,  Griethuysen, C. van ,  Ayarza, Miguel Angel ,  Vilela, L ,  Zech, W. ,  [Aggregation studied by laser diffraction in relation to plowing, soil organic matter, and lime in the Brazilian cerrados] ,  Aggregation studied by laser diffraction in relation to plowing, soil organic matter, and lime in the Brazilian cerrados
Book Chapter 1999

Autor: Westerhof, R Vilela, L Ayarza, Miguel Angel Zech, W.

The permanganate oxidation procedure is easily performed and may help monitor large areas for their soil organic matter (SOM) quality and nitrogen (N) availability. Knowledge of the chemical characteristics of fractions that are lost or remain after oxidation will help explain results obtained by...

Enlace original: https://cgspace.cgiar.org/handle/10568/55134

Investigación en Agricultura
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Westerhof, R ,  Vilela, L ,  Ayarza, Miguel Angel ,  Zech, W. ,  [Characterization labile and stable nitrogen] ,  Characterization labile and stable nitrogen
Book Chapter 1999

Autor: Renz, TE Neufeldt, Henry Ayarza, Miguel Angel Resck, DVS Zech, W.

In the Brazilian savannas, or Cerrados the rapid advance in agriculture and cattle ranching is affecting soils through, for example, accelerated erosion and depletion of soil organic matter (SOM). Changes in soil microbial biomass are good indicators of changes in SOM. We therefore assessed the e...

Enlace original: https://cgspace.cgiar.org/handle/10568/55138

Investigación en Agricultura
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Renz, TE ,  Neufeldt, Henry ,  Ayarza, Miguel Angel ,  Resck, DVS ,  Zech, W. ,  [Microbial biomass, microbial activity, and carbon pools under different land-use systems in the Brazilian cerrados] ,  Microbial biomass, microbial activity, and carbon pools under different land-use systems in the Brazilian cerrados
Book Chapter 1999

Autor: Freibauer, A. Westerhof, R Ayarza, Miguel Angel Silva, J.E. da Zech, W.

Short-term changes in soil aggregation, total and particulate organic C and N were studied in cropping and pasture systems of the Brazilian savannas, also known as the Cerrados. Furthermore, the concepts of a hierarchical aggregate structure and of the interaction of soil structure with particula...

Enlace original: https://cgspace.cgiar.org/handle/10568/55129

Investigación en Agricultura
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Freibauer, A. ,  Westerhof, R ,  Ayarza, Miguel Angel ,  Silva, J.E. da ,  Zech, W. ,  [Short-term variation in aggregation and particulate organic matter under crops and pastures] ,  Short-term variation in aggregation and particulate organic matter under crops and pastures
Book Chapter 1999

Autor: Lilienfein, J Wilcke, W. Neufeldt, Henry Ayarza, Miguel Angel Zech, W.

This study assessed the influence of land use (continuous cropping, CC; tree plantations, F; pasture, PG; and native savanna, NS) on P concentrations and partitioning in bulk soil and two aggregate size fractions of two Oxisols, one loamy and one clayey. The quantity and quality of physically pro...

Enlace original: https://cgspace.cgiar.org/handle/10568/55136

Investigación en Agricultura
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Lilienfein, J ,  Wilcke, W. ,  Neufeldt, Henry ,  Ayarza, Miguel Angel ,  Zech, W. ,  [Phosphorus pools in bulk soil and aggregates of differently textured oxisols under different land-use systems in the Brazilian cerrados] ,  Phosphorus pools in bulk soil and aggregates of differently textured oxisols under different land-use systems in the Brazilian cerrados
Book Chapter 1999

Autor: Westerhof, R Vilela, L Ayarza, Miguel Angel Zech, W.

Soil organic matter quality is usually seen as a major attribute of soil quality. In this study, we extracted organic carbon with water (WEOC) or with potassium permanganate (PEOC). We assessed these extractions for their potential as sensitive indicators of the effect of land use on two importan...

Enlace original: https://cgspace.cgiar.org/handle/10568/55132

Investigación en Agricultura
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Westerhof, R ,  Vilela, L ,  Ayarza, Miguel Angel ,  Zech, W. ,  [Carbon fractions as sensitive indicators of quality of soil organic matter] ,  Carbon fractions as sensitive indicators of quality of soil organic matter
Book Chapter 1999

Autor: Neufeldt, Henry Ayarza, Miguel Angel Resck, DVS Zech, W.

The effects of land-use change on the structure of Oxisols in the Brazilian savannas (also known as the Cerrados) are still insufficiently understood. We therefore studied loamy and clayey Oxisols under natural savanna, crop, pasture, and reforestation to (1) quantify management-induced changes i...

Enlace original: https://cgspace.cgiar.org/handle/10568/55127

Investigación en Agricultura
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Neufeldt, Henry ,  Ayarza, Miguel Angel ,  Resck, DVS ,  Zech, W. ,  [Distribution of water-stable aggregates and aggregating agents in oxisols of the Brazilian cerrados] ,  Distribution of water-stable aggregates and aggregating agents in oxisols of the Brazilian cerrados
Book Chapter 1999

Autor: Renz, TE Neufeldt, Henry Ayarza, Miguel Angel Silva, J.E. da Zech, W.

Plant production in the Brazilian savannas, also known as the Cerrados, is limited mainly by low P availability. In tropical soils, rich in sesquioxides, P supply of plants depends heavily on the transformation of organic P by phosphatase enzymes into HPO 4 2- and H 2 PO 4-. We examined two Oxiso...

Enlace original: https://cgspace.cgiar.org/handle/10568/55137

Investigación en Agricultura
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Renz, TE ,  Neufeldt, Henry ,  Ayarza, Miguel Angel ,  Silva, J.E. da ,  Zech, W. ,  [Acid monophosphatase: an indicator of phosphorus mineralization or of microbial activity? A case study from the Brazilian cerrados] ,  Acid monophosphatase: an indicator of phosphorus mineralization or of microbial activity? A case study from the Brazilian cerrados
Book Chapter 1999

Autor: Westerhof, R Silva, J.E. da Ayarza, Miguel Angel Zech, W.

We examined whole-soil samples and particle-size fractions to study the distribution of different phosphorus (P) fractions after land-use change from native savanna to crops, pasture, and reforestation on clayey and loamy Oxisols of the Brazilian savannas. Phosphorus was extracted sequentially, a...

Enlace original: https://cgspace.cgiar.org/handle/10568/55135

Investigación en Agricultura
Enlace permanente
Westerhof, R ,  Silva, J.E. da ,  Ayarza, Miguel Angel ,  Zech, W. ,  [Phosphorus fractions under different land-use systems in oxisols of the Brazilian cerrados] ,  Phosphorus fractions under different land-use systems in oxisols of the Brazilian cerrados

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