ABSTRACT Growing off-season cover crops effectively enhances ecological diversity and improves nutrient cycling in agricultural systems, particularly when nutrient losses and low use efficiency are prominent. This study aimed to assess the interaction between different off-season cover crops and varying nitrogen (N) and phosphorus (P) application rates on common beans, soybeans, and corn yields, as well as on soil organic matter (SOM) and available P content (Mehlich-1) in a Cerrado loamy soil. The experiment was conducted as a strip-plot factorial […]

Crop residues on the soil surface of no-till systems can intensify ammonia volatilization from N fertilizers applied to cereal crops. This study assessed the magnitude of N losses through ammonia volatilization from urea applied to no-till winter (wheat) and summer crops (maize) on a Typic Hapludox in the south-central region of Paraná, southern Brazil. In addition, the potential of alternative N sources (urea with urease inhibitor, liquid fertilizer, ammonium nitrate and ammonium sulfate) and different urea managements (fertilizer applied in […]

Experiments testing the efficiency of arbuscular mycorrhizal fungi (AMF) originating from the same soil sample complement studies of taxonomic diversity by assessing functional relationships within mycorrhizal communities. In this study fungal isolates from three distinct communities were evaluated regarding their efficiency to increase dry biomass production and P content in two mycotrophic hosts. In the first experiment, the effect of 13 AMF isolates from the JA205, MN414, and VA105 communities were screened in order to test the hypothesis that at least […]

Aluminum tolerant wheat varieties can present increased efficiency of phosphorus use in presence of aluminum. A greenhouse experiment was conducted in 1994 to compare the wheat cultivars (Toropi) and (CNT 8), considered efficient and inefficient, respectively, in relation to phosphorus use. Nutrient solutions containing two phosphorus (1.6 and 32.3 µmol L-1) and two aluminum (0.0 and 37.0 µmol L-1) concentrations were tested. Root morphology and phosphate use were established for the plants, which were harvested from the pots on the 31th day. Roots of the Toropi […]

Manures used as phosphorus sources may have different efficiencies from those of commercial soluble fertilizers. These efficiencies may vary according to the manure origin and to the proportions of its total P in different chemical fractions. A greenhouse experiment was conducted in order to estimate the efficiencies of dairy cattle and chicken manures as phosphorus source, in comparison to triple superphosphate (TSP), as well as to relate these efficiencies to their P fractions. The treatments were: control, without fertilizer or […]

To get more efficient wheat varieties in phosphorus uptake and/or utilization it is important to look for the causes of the greater efficiency of particular varieties. One experiment in nutrient solution with four concentrations of phosphorus (1.6, 4.8, 12.9 and 32.3 µmol L-1) was conducted to compare efficient (Toropi and IAC 5) and inefficient cultivars (IAS 20 and CNT 8) in phosphorus uptake in relation to the amount of phosphorus taken up, phosphorus translocation and utilization, dry matter production and […]