ABSTRACT Phosphorus (P) is one of the most limiting elements for plant nutrition in tropical and subtropical soils due to its high binding energy on the surface of iron and aluminum oxides and hydroxides. Flooded rice cultivation occurs in lowlands, influencing redox reactions and P dynamics. This study aimed to evaluate the forms of phosphorus and their lability after soil reoxidation subsequent to a period of flooding for irrigated rice cultivation following four seasons of cultivation with soybean-ryegrass and corn-white […]

ABSTRACT In some rural properties of Brazil, soil and water conservation practices are partially or inappropriately implemented, intensifying soil erosion, even in no-tillage (NT) areas. This study aimed to check the farmer’s understanding of conservation agriculture (CA) and assess whether they are using practices appropriate to soil conservation. A basin in the state of Paraná, in Southern Brazil, was selected. Surveys were conducted based on a structured questionnaire and in-person interviews of 234 farmers. Among these farmers, 67 % do […]

ABSTRACT Sandy soil often has low nitrogen (N) stock. Thus, crops grown in sandy soil rely on high levels of N fertilization. The use of cover crops and efficient fertilizers can increase N stock in the soil and N availability in the topsoil, and reduce overall fertilizer costs. The objective of this study was to evaluate the effects of cover crops (fallow, a single grass species (ruzigrass), two grass species (ruzigrass + millet), one grass species (millet) with legumes [lime-yellow […]

ABSTRACT The concept of a no-tillage system (NTS), or “Sistema Plantio Direto,” was established in Brazil from the evolution of no-tillage (NT) or “Plantio Direto,” given the edaphoclimatic conditions and the need to promote chemical, physical and biological improvements in cultivated soils. While “Plantio Direto” is a conservationist practice, “Sistema Plantio Direto” presents itself as an agricultural production system based on the simultaneous adoption of minimum soil disturbance, maintenance of permanent soil cover and crop rotation. This study reviews the […]

The area under the no-tillage system (NT) has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean) on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy […]

The no-till system with complex cropping sequences may improve the structural quality and carbon (C) sequestration in soils of the tropics. Thus, the objective of this study was to evaluate the effects of cropping sequences after eight years under the no-till system on the physical properties and C sequestration in an Oxisol in the municipality of Jaboticabal, Sao Paulo, Brazil. A randomized split-block design with three replications was used. The treatments were combinations of three summer cropping sequences – corn/corn […]

Pig slurry (PS) represents an important nutrient source for plants and using it as fertilizer makes greater nutrient cycling in the environment possible. The aim of this study was to assess how PS application over a period of years can affect grain yield, dry matter production and nutrient accumulation in commercial grain and cover crops. The experiment was carried out in an experimental area of the Universidade Federal de Santa Maria, in Santa Maria, RS, Brazil, from May 2000 to […]

Animal manure is applied to the soil as a nutrient source, especially of nitrogen, to plants. However, manure application rates can be reduced with the use of N fertilizer in topdressing. The aim of this study was to evaluate crop responses to different application rates of animal manure sources, used alone and supplemented with mineral N topdressing, in a no-tillage system. The study was carried out from 2005 to 2008 on a Hapludalf soil. The treatments consisted of rates of […]

The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass – Brachiaria ruziziensis) in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation […]

Soil quality in no-till systems is related to the crop systems and may be evaluated through particulate organic matter (>53 ∝m) stock due to the functionality this property provides to the soil and its sensitivity to management practices. Aiming to assess soil quality no-till crop systems, this study was carried out through a long-term experiment (21 years) in a Latossolo Vermelho distrófico típico (typical Oxisol) in Ponta Grossa, PR, Brazil. Six crop systems were assessed. Wheat-TR (Triticum aestivum L.), soybean-SO […]