Structural quality of a no-tillage red latosol 50 months after gypsum aplication

Revista Brasileira de Ciência do Solo

Marcelo Marques Lopes Müller²  Cassio Antônio Tormena¹  Aline Marques Genú²  Luiz Fernando Machado Kramer¹  Leandro Michalovicz¹  Eduardo Fávero Caires¹ 

[1] ,UNICENTRO South-Central State University Dept. AgronomyGuarapuava PR ,Brazil

关键词: phosphogypsum;    soil physics;    visual score;    aggregation forces;    fosfogesso;    física do solo;    escore visual;    forças de agregação;   

DOI  :  10.1590/S0100-06832012000300030

来源: SciELO

【 摘 要 】

Gypsum application may enhance the soil quality for plants in terms of soil chemical and physical properties. The objective of this study was to evaluate the effects of gypsum application on the structural quality of a no-tillage Red Latosol. The experiment was initiated in September 2005 in Guarapuava-PR, with gypsum applications of 0; 4; 8; and 12 Mg ha-1 on the soil surface. In November 2009, two soil blocks were sampled from the 0-0.3 m layer for visual evaluation of the soil structure quality (Sq) and to determine the aggregate-tensile strength (ATS). Soil penetration resistance (PR) and gravimetric moisture (H%) of the 0-0.300 m layer were evaluated, and soil cores were collected (layers 0.000-0.075 and 0.075-0.150 m), to determine soil bulk density (BD), total soil porosity (TP), microporosity (Mi), and macroporosity (Ma). Data were subjected to analysis of regression at 5 %. No significant effects of gypsum application on ATS and H % of aggregates were observed, but for Sq, a quadratic effect (0.000-0.075 m) and linear increase (0.075-0.150 and 0.150-0.300 m) were stated, indicating soil quality decrease, although Sq remained mostly below 3.0, with good to intermediate soil quality. Soil PR increased with gypsum, but also remained below critical levels. No effect was observed for soil H % at the moment of PR determination on the field. The gypsum applications decreased BD in the 0.075-0.150 m layer, and increased PT and Ma, while in 0.000-0.075 m some Ma was converted to Mi, without affecting PT and BD. These last results indicate a gain in soil structural quality by gypsum applications, but the higher scores of soil structure and values of soil penetration resistance, though still below thresholds, should be monitored to prevent limitations to soil use in the future.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License