Physical quality of an anionic acrustox under different management systems
01/Jun/2009
Agricultural management systems can cause degradation of the soil physical quality, with consequences to the environment and crop yields. Thus, the purpose of this study was to evaluate and compare the physical quality of an anionic Acrustox in Guaíra, São Paulo state, under the following treatments: no-tillage with irrigation, no-tillage without irrigation, croppasture rotation, conventional tillage, and native forest. The organic matter content, aggregate stability, soil bulk density, porosity and index S were evaluated. Results showed that human intervention reduced […]
Physical properties and organic matter content of an ultisol cultivated with cassava under different managements
01/Dec/2008
The maintenance and improvement of soil quality are crucial to the stability, sustainability and productivity of natural ecosystems and agroecosystems. The understanding and quantification of the impact of tillage systems in their physical quality are fundamental in the development of sustainable agricultural systems. This study was carried out to evaluate the effects of management practices on physical properties and organic matter content of an Ultisol cultivated with cassava following the use of distinct cover crops. A field experiment was carried […]
Movement of lime particles in the profile of an Inceptisol under no-tillage
01/Apr/2004
Surface lime application has shown to be efficient for correcting soil acidity in no-tillage systems. Contrary to the expected, this effect has occurred in deeper soil layers and in a relatively short time, in spite of the low solubility of liming materials. The objectives of this research were: (a) to detect the presence of calcite and dolomite minerals originated from lime in the soil; (b) to verify chemical alterations related to soil acidity in the soil profile due to surface […]
Changes in acid soil properties by superficial and incorporated liming on natural pasture
01/Dec/2000
Superficial liming is an alternative way to correct soil acidity in no till system. The objective of this study was to evaluate the effects of superficial and incorporated liming on native pasture. The experiment was carried out at the experimental field of the Soil Science Department, at the Universidade Federal de Santa Maria (Brazil), on a Plinthaquult medium texture and with high potential acidity under native pasture. Lime rates of 0.0, 2.0, 8.5 and 17.0 Mg ha-1 were used. On […]
Surface application of lime under a no-tillage system
01/Mar/2000
The efficiency of surface application of lime under a no-tillage system is doubtful, particularly with regard to subsoil acidity and to methods of lime requirement determination. A field experiment was carried out on a dystrophic Dark Red Latosol (Haplortox) from Ponta Grossa, Paraná, Brazil, from 1993 to 1998, to evaluate the extent of downward movement of lime applied on the surface under a no-tillage system, and the effect on crop rotation grain yields. A randomized complete block design was used, […]
Winter cover crops before corn and their effects on soil organic carbon, in a no tillage system
01/Jun/1999
Soil in natural conditions are in steady state in the environment. However, inadequate management can cause degradation mainly in the organic matter fraction, impiring the sustainability of agricultural systems. This experiment was conducted for 6 consecutive years in a Hapludalf (Red Yellow Podzolic Soil), at the experimental area of Soil Science Department UFSM. The objective was to evaluate the effects of plant successions on the carbon dynamic. The plant successions used were common vetch (Vicia sativa)/corn (Zea mays), blue lupine […]
Corn, wheat and soybean yields as a function of the changes in soil chemical characteristics due to surface application of lime and gypsum under a no-tillage system
01/Jun/1999
This experiment was carried out on a dystrophic Dark-Red Latosol from Ponta Grossa, Paraná, Brazil, to evaluate the yield of corn, wheat and soybean as a function of the changes in the chemical characteristics of soil due to surface application of lime and gypsum under a no-tillage system. A completely randomized block design was used, with three replications, in a split-plot experiment. Dolomitic limestone was applied at rates of 0, 2, 4 and 6 t ha-1 (main plots) in July […]
Changes in soil chemical characteristics by surface application of lime and gypsum and soybean response in no-tillage system
01/Mar/1998
The experiment was carried out on a dystrophic Dark Red Latosol from Ponta Grossa, Paraná State, Brazil, to evaluate the effects of the surface application of lime and gypsum on soil chemical characteristics and soybean response in no-tillage. A randomized complete block design was used, with three replications, in a split-plot experiment. Dolomitic limestone was applied at rates of 0, 2, 4 and 6 t ha-1 (main plots) in July of 1993; gypsum was applied at rates of 0, 4, […]
NH3-N volatilization in corn crop: II- evaluation of solid and fluid sources under no-tillage and conventional systems
01/Sep/1997
Two field experiments were carried out with corn, using no-tillage system (NTS) over oat residues, in a clay dark-red latosol at the Centro de Pesquisa Novartis – Seeds, in Uberlândia, State of Minas Gerais, Brazil, and conventional tillage system over soybean residues (CTS), in a sandy red-yellow latosol at the Santa Terezinha farm, Uberlândia. The objective of this study was to evaluate the NH3-N volatilized from nitrogen sources, side-dressed applications, of approximately 100 kg ha-1, applied in the middle of […]
