ABSTRACT Soil aggregates and their stability affect a wide range of soil properties. This study aimed to (a) verify whether biogenic aggregation provides higher macro- and microaggregate stabilization, and (b) evaluate whether biogenic aggregates are associated with higher labile organic carbon and glomalin contents. Three management systems were evaluated (permanent pasture, PP; no-tillage system, NT; and no-tillage + Brachiaria system, NT+B) as well as a reference area (Atlantic Forest biome vegetation, NF). According to their origin or formation pathway, the […]

ABSTRACT Conventional tillage and intensive machinery traffic are the major causes of physical soil degradation in sugarcane fields. This study evaluates the impact of adopting conservation management practices during sugarcane planting on soil physical properties and stalk yield of sugarcane in the municipality of Ibitinga, state of São Paulo, Brazil. The experimental design (split-block) included four cover crops and three soil tillage systems, with three repetitions. For comparison purposes, a control treatment was also included (without cover crop and under […]

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 […]

ABSTRACT The intensive nature of soil use in vegetable production areas has led to a marked decrease in soil quality. The objective of this study was to evaluate the effects of adoption of soil management systems on vegetable production with regards to the chemical properties of a Rhodic Ferralsol after five years and to evaluate the use of the Principal Component Analysis (PCA) statistical tool in discriminating the different treatments. The experiment was conducted under field conditions in central Brazil […]

ABSTRACT The biological nitrogen fixation (BNF) process in grasses is caused by diazotrophic bacteria, particularly Azospirillum brasilense. However, studies are lacking on BNF efficiency to define how much mineral nitrogen (N) can be applied to achieve more sustainable high yields. Furthermore, there should be an analysis of whether urea with the urease enzyme inhibitor NBPT is less harmful, benefiting BNF in grasses. The objective of this study was to evaluate the effect of N sources and N rates associated with […]

ABSTRACT Autumn maize intercropped with tropical forages can raise the amount of crop residues and improve nutrient cycling, favoring subsequent soybean crop. The objective of this study was to evaluate the effect of forms of implementation of intercropping of irrigated autumn maize with tropical forages on yield, decomposition, nutrient accumulation and release, and on the ratio of lignin/total N of forage residues, yield components, and grain yield of subsequent soybean, and on soil physical and chemical properties, under no-tillage in […]

ABSTRACT Perennial forage crops used in crop-livestock integration (CLI) are able to accumulate large amounts of straw on the soil surface in no-tillage system (NTS). In addition, they can potentially produce large amounts of soluble organic compounds that help improving the efficiency of liming in the subsurface, which favors root growth, thus reducing the risks of loss in yield during dry spells and the harmful effects of “overliming”. The aim of this study was to test the effects of liming […]

Estimation of soil load-bearing capacity from mathematical models that relate preconsolidation pressure (σp) to mechanical resistance to penetration (PR) and gravimetric soil water content (U) is important for defining strategies to prevent compaction of agricultural soils. Our objective was therefore to model the σp and compression index (CI) according to the PR (with an impact penetrometer in the field and a static penetrometer inserted at a constant rate in the laboratory) and U in a Rhodic Eutrudox. The experiment consisted […]

Soil aggregation and the distribution of total organic carbon (TOC) may be affected by soil tillage and cover crops. The objective of this study was to determine the effects of crop rotation with cover crops on soil aggregation, TOC concentration in the soil aggregate fractions, and soil bulk density under a no-tillage system (NTS) and conventional tillage system (CTS, one plowing and two disking). This was a three-year study with cover crop/rice/cover crop/rice rotations in the Brazilian Cerrado. A randomized […]

Soil compaction is one of the main degradation causes, provoked by inappropriate agricultural practices that override the limitations of the soil physical properties. Preconsolidation pressure and penetration resistance have proved effective as alternative to assess and identify soil compaction. Based on the interpretation of these physico-mechanical parameters, compaction can be prevented with a better adjusted soil management. This study was performed to generate preconsolidation pressure and penetration resistance models for Latososlo Vermelho-Amarelo distrófico (Oxisol) under various managements and uses; and […]