The semivariogram provides a visual assessment of spatial dependence but without directly resulting in a single numerical value that expresses the measurement of such dependence. However, from the estimated parameters of the theoretical model adjusted to the experimental semivariogram, it is possible to construct a measure of this spatial dependence. Currently, there are two indices in literature that are widely used; however, these indices show some gaps. The aim of this study was to propose a new index to measure […]

Measurement of chlorophyll fluorescence can be a useful tool for detecting changes in the photosynthetic apparatus of plants. With the understanding that early detection of zinc (Zn) contamination is fundamental in environmental monitoring, the aim of this study was to assess Zn stress in castor bean (Ricinus communis) plants using X-ray chlorophyll fluorescence. The changes brought about by Zn in photosynthetic pigments and in the mineral composition of plants were also studied. Castor bean plants were grown for 28 days […]

Inconclusive responses of the adult coffee plant to phosphorus fertilization have been reported in the literature, especially when dealing with application of this nutrient in high density planting systems. Thus, this study was carried out for the purpose of assessing the response of adult coffee plants at high planting density in full production (in regard to yield and their biennial cycle/stability) to the addition of different sources and application rates of P in the Zona da Mata region of Minas […]

Nutrient availability during the year can affect the performance of macadamia (Macadamia integrifolia). However, there is no information about this crop responses to split application of fertilizer under Brazilian conditions. The aim of this study was to evaluate the influence of splitting the application of chemical fertilizers on the nutrition, yield, and quality of nuts of the macadamia nut tree. The experiment was conducted over three growing seasons on an Oxisol in Jaboticabal, State of São Paulo, Brazil. A randomized […]

Soil properties have an enormous impact on economic and environmental aspects of agricultural production. Quantitative relationships between soil properties and the factors that influence their variability are the basis of digital soil mapping. The predictive models of soil properties evaluated in this work are statistical (multiple linear regression-MLR) and geostatistical (ordinary kriging and co-kriging). The study was conducted in the municipality of Bom Jardim, RJ, using a soil database with 208 sampling points. Predictive models were evaluated for sand, silt […]

Over the past three decades, pedotransfer functions (PTFs) have been widely used by soil scientists to estimate soils properties in temperate regions in response to the lack of soil data for these regions. Several authors indicated that little effort has been dedicated to the prediction of soil properties in the humid tropics, where the need for soil property information is of even greater priority. The aim of this paper is to provide an up-to-date repository of past and recently published […]

Rice husk ash (RHA) is a by-product from the burning of rice husk that can have favorable effects on the soil in terms of acidity correction. The objectives of this study were to determine the effective calcium carbonate equivalent (ECC) of RHA under field conditions, and establish technical criteria as a basis for estimating the overall ECC of RHA. The 12 treatments of the experiment consisted of 10 RHA dosages (0, 10, 20, 30, 40, 60, 80, 100, 120, and […]

The increasing level of land degradation has led to the adoption of agricultural management practices that seek to combine agricultural production and soil conservation. Among these, the practice of Crop-Livestock Integration (CLI) has intensified in West-Central Brazil. In order to assess the long-term effect of the CLI system and seasonality on the community of soil macrofauna and oxidizable fractions of total organic C in croplands and the Cerradão (Brazilian tropical savanna), a study was developed at the Cabeceira Farm in […]

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of […]

The nutritional state of the pineapple plant has a large effect on plant growth, on fruit production, and fruit quality. The aim of this study was to assess the uptake, accumulation, and export of nutrients by the irrigated ‘Vitória’ pineapple plant during and at the end of its development. A randomized block statistical design with four replications was used. The treatments were defined by different times of plant collection: at 270, 330, 390, 450, 510, 570, 690, 750, and 810 […]