Least limiting water range to evaluate soil compaction and physical quality of an oxisol cultivated with soybean
01/Dec/2007
Soil physical quality is essential for plant growth and sustainable agricultural systems. This study aimed to evaluate the efficiency of the least limiting water range (LLWR) to monitor soil compaction and soil physical quality for soybean, without and with irrigation. The study was carried out in an clayer Red Latosol (Oxisol) (21 ° 14 ‘ 53 ” S; 48 ° 17 ‘ 20 ” W; 540 m asl). The experiment was entirely randomized, in a 6 x 2 factorial scheme, with four repetitions. The compaction treatments were: T1 = without compaction; T2 = 1 pass of a 4 t […]
Determination of the subsurface quality index in a Cohesive Argisolic Yellow Latosol under natural forest in Coastal Plains
01/Dec/2007
Soil is an essential natural resource for life. Its overall capacity to function as substratum for plants, as environmental filter and regulator of gas, water and energy flow is defined as soil quality. An soil quality index can be used to monitor the effects of agricultural use on the soil attributes. The objective of this study was to determine a soil quality index (SQI) for the subsurface horizons of a cohesive argisolic Yellow Latosol (LAx) of Coastal Plains under natural […]
Homogeneity of soil physical quality in-between rows of an orange orchard with groundcover management systems
01/Aug/2007
The soil physical quality is fundamental for the sustainability of citrus production. The objective of this study was to evaluate the homogeneity of soil physical quality in-between the rows of an orange orchard with groundcover management systems. The study was performed in an experimental field with groundcover systems in-between the rows of ‘Pêra orange’ on ‘Rangpur’ lime rootstock on a Typic Paleudult, in 1993, in Alto Paraná, in the northwestern region of the state of Paraná, Brazil. An experimental design […]
Soil quality in soil management systems in dwarf cashew crops
01/Apr/2007
Brazil is the most important exporter of cashew nut in the world. The production is concentrated in the northeast region, which accounts for 97 % of the national production. However, in the recent years the cashew nut production has been declining, specially in the state of Ceará, mainly due to inadequate soil management. The aim of this study was to evaluate alterations in the physical and chemical properties of an Ultisol submitted to distinct soil management practices and the development […]
Microbial biomass and light organic matter in soils under organic and conventional systems in the Chapada da Ibiapaba – CE, Brazil
01/Apr/2006
Several studies reveal that the substitution of native vegetation by agricultural systems results in decreases in the C and N soil organic matter pools. Aiming to test the hypothesis that management practices favoring organic residue inputs promote increases in the most sensitive organic matter pools, the present study intended to study areas of an organic management system of acerola fruit production and a conventional cultivation area cropped with carrot and beet in crop rotation with corn. These areas belong to […]
Evaluation of physical attributes of a dystrophic Red Nitosol under no-tillage, conventional tillage and native forest systems
01/Jul/2005
As the time of adoption of no-tillage systems lengthens thee occur modification in soil physical attributes; however, these effects are not well quantified yet. The present study had the objective to evaluate the effect of time of adoption of a no-tillage system, compared to native forest and a conventional tillage system using physical attributes of a Dystroferric Red Nitosol. The evaluated systems were: PD1 (one year of adoption of no-tillage), PD4 (no-tillage for four years), PD5 (no-tillage for five years), […]
Physical soil properties of conventional tillage and no-tillage, in crop rotation and succession, compared with natural pasture
01/Feb/2004
In soils with naturally favorable characteristics for cultivation, conventional tillage degrades the physical soil properties, since this management system causes the rupture of aggregates, soil compaction, and eliminates soil cover. No-tillage, on the other hand, maintains soil cover and improves physical properties, but consolidates the surface layer. Our study was conducted on a Haplumbrept soil, from May 1995 to April 2001. Five soil tillage treatments were used: conventional tillage crop rotation (CTR), conventional tillage crop succession (CTS), no-tillage crop rotation […]
Total stocks of organic carbon and its pools in acrisols under forest and under maize cultivated with mineral and organic fertilization
01/Oct/2003
Soil organic matter and its different pools have key importance in nutrient availability, soil aggregation, and in the greenhouse gas fluxes between the earth surface and the atmosphere. The objectives of this study were: a) to evaluate the effect of maize production systems under organic and mineral fertilization on total organic carbon (TOC) and total nitrogen (TN) stocks and on organic carbon pools (C) in an Acrisol; and b) to estimate the contribution of these systems in the atmospheric CO2 […]
Humification decrease of soil organic matter under no-tillage
01/Jun/2003
The less oxidative environment in soils of no-tillage systems decreases the humification degree of organic matter. To test this hypothesis, the concentration of semiquinone free radicals (SFR) of organic matter from the surface layer (0 to 25 mm) of a Humic Cambisol (Lages, Santa Catarina State) was evaluated. The soil had been cultivated for 8 yrs under conventional tillage (CT), reduced tillage (RT), and no-tillage (NT). The SFR concentration in organic matter was assessed by electron spin resonance (ESR) in the granulometric […]
Physical properties of a south Brazilian Oxisol as affected by no-tillage and conventional tillage systems
01/Jun/2003
Soil management affects the soil physical quality, but the magnitude of the changes is dependent of use time and regional edaphoclimatic conditions. The objective of this study was to evaluate the long-term (21 yr) effect of conventional tillage (CT) and no-tillage (NT) systems on some physical properties in the 0.2 m top layer of an Oxisol from Paraná, southern Brazil. In comparison with an adjacent forest soil used as reference, the use of CT system increased the soil bulk density, penetrometer resistance […]