Volume 22, Number 1, 1998

The packing condition of the soil is important for providing direction for land management. In soils developed from recent sediments, the tendency to packing may be related to inherited characteristcs from sedimentation conditions. In a soil toposequence from sandy sediments of Barreiras geological group, in Caravelas city – Bahia, eight soil profiles were selected, five of them from a eucalypt plantation. The soils were allocated in five great groups: Fluvaquent (P1),Duraquod (P2, P8), Haplorthod (P3), Hapludult (P4, P5, P7) and […]

Basalt rocks are one of the most common parent materials of large areas of soil in southern Brazil. Several major plant nutrients are present in its composition. The objective of this study was to evaluate the effect of the addition of increased rates of ground basalt rock on the nutrient availability of soil, during three periods of incubation. The rocks tested were a microcrystalline and an olivine-basalt. The rates of basalt rock, corresponding to 0, 5, 10, 25, 50 e […]

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 […]

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, […]

The experiment was carried out in nutrient solution, under greenhouse conditions at the Soil Science Department – Lavras Federal University, to evaluate the influence of different ammonium/nitrate proportions on the growth of Phaseolus vulgaris L. cultivars: Rio Tibagi, Eriparza and Carioca. Nitrogen in the nutrient solution was supplied at 4 mmol L-1 with different NH4+:NO3– proportions (0/4; 1/3; 2/2; 3/1 and 4/0). Throughout the growth period the pH of the nutrient solution was monitored. After harvesting, root and shoot dry […]

Agroforestry systems combine crop productivity with environmental sustainability while conserving fertilizer through nutrient cycling. Plant biomass production and nutrient inputs were measured in an alley cropping system and in native cerrado site at Botucatu, State of São Paulo, Brazil, and the influence of agroforestry practices on the soil chemical attributes were determined. Leucaena was planted in 1987, in hedgerows 6 m apart, following lime and P applications. Legume hedgerows were pruned annually, allowing for cereal intercropping of rye with oat […]

Supplying capacity, response to fertilization and residual effect of K fertilization were evaluated in a twelve-year soybean field experiment on a Haplohumox soil, in Campos Novos, State of Santa Catarina, Brazil. Treatments consisted of: four levels of K2O (0, 80, 160 and 320 kg ha-1), applied only in the first cropping, on the whole plots; three levels of K2O (0, 40 and 80 kg ha-1), applied annually in the sub-plots from the fifth year; one treatment with application of 40 […]

Soybean response to potassium fertilization was evaluated over a twelve-year period in a field experiment on a Haplohumox soil, in Campos Novos, State of Santa Catarina, Brazil. Treatments consisted of a combination of four levels of K2O applied in the first year (0, 80, 160 and 320 kg ha1), and three levels of K2O (0, 40 and 80 kg ha-1) applied annually from the fifth year. The critical level of K in the soil and in the leaves was determined […]

The new planting areas of cacao in the Amazon basin of Brazil were established on eutrophic soils, especially structured Purple Earth, and on Yellow Latosol or dystrophic podzolic soils. The nutrient requirements of cacao trees cultivated on these soils were still unknown. The effects of N, P and K on the productivity of cacao were determined in two experiments conducted in the counties of Medicilândia, along the Transamazonian Highway, and Benevides, Pará, Brazil. The cacao crop of the hybrid Sca […]

The effects of applying micronutrients, cattle manure, lime and splitting application of NPK fertilizers on the yield and the incidence of witches’ broom disease of cacao caused by Crinipellis perniciosa were determined in two experiments carried out on structured Terra Roxa soil (TR) and Yellow Latosol (LA), in Pará State, from 1988 to 1993, after the slash and burn of the forest. The hybrid (Sca 6 x Be 10) cacao crop was introduced utilizing banana (Musa spp.), as temporary shading, […]