Clovis Orlando Da Ros

Eficiência de malhas amostrais utilizadas na caracterização da variabilidade espacial de fósforo e potássio

The objective of the research was to evaluate the efficiency of the sampling grids, used in areas managed with precision agriculture, for the characterization of spatial variability levels of phosphorus (P) and potassium (K). The study was conducted in 30 agricultural areas, located in Rio Grande do Sul state, presenting soils classified as Oxisols. The sizes of the sampling grids studied were: 100x100m (10 areas), 142x142m (10 areas) and 173x173m (10 areas).Were analyzed the levels of P and K, in depth of sampling from 0.00-0.10m. The data were subjected to descriptive statistical analysis and geostatistical analysis. In, general, the areas showed average levels of P and K suitable for crops development. However, were observed subareas with low levels of P, justifying fertilization on site-specific. Based on geostatistical parameters, sizes of the sampling grids used are efficient to capture the different scales of spatial variability of P and K, however, it is indicated smaller sampling grids to consider the spatial variability over short distances.

Atributos químicos do solo e produtividade de girassol e milho em função da aplicação de composto de lixo urbano

The use of composted urban waste as a source of nutrients in agriculture is an economic alternative for discarding this material. However, due to the diversity of materials that compose this waste, long term studies on its effects on soil chemical attributes and crop yield are necessary. This study aimed at evaluating the potential of urban waste compost (UWC) as a fertilizer for sunflower and maize crops, as well as its effects on the chemical attributes of an Oxisol. A field experiment, with UWC doses of 0 Mg ha -1 , 10 Mg ha -1 , 20 Mg ha -1 , 30 Mg ha -1 and 40 Mg ha -1 and mineral fertilization according to the recommendation for each crop, was carried out. The results showed an increase in soil pH from 6 to 6.5, with the UWC application. The soil potential acidity decreased linearly from 3.0 cmol c dm -3 to 2.4 cmol c dm -3 , contributing to the SMP index increase, what reflected on the increase of the soil cation exchange capacity. The bases saturation increased from 77% to 85%, mainly due to the increase in calcium and magnesium levels. The use of UWC resulted in sunflower grain yield similar to that for mineral fertilization, at 10 Mg ha -1 , 20 Mg ha -1 and 30 Mg ha -1 , being significantly higher at 40 Mg ha -1 . The maize grain yield at or above 20 Mg ha -1 of UWC did not differ from the mineral fertilization. The UWC presented potential to replace the mineral fertilization for sunflower and maize crops.

Sampling grids used to characterise the spatial variability of pH, Ca, Mg and V% in Oxisols

Knowledge of spatial variability is an important factor to be considered in planning a program of soil sampling and crop management under precision agriculture (PA). In this context, the aim of this work was to evaluate the efficiency of the dimensions of sampling grids used in the state of Rio Grande do Sul (RS), Brazil to characterise the spatial variability of the attributes pHwater, base saturation (V%), calcium (Ca) and magnesium (Mg) levels. The study was carried out on 30 agricultural sites located in the northern region of RS, having soils classified as Oxisols and managed using the tools of PA. The dimensions of the grids under study were: 100 x 100 m (10 areas), 142 x 142 m (10 areas) and 173 x 173 m (10 areas). Soil was collected at a depth of 0.00 to 0.10 m. The data for pHwater, V%, Ca and Mg were subjected to exploratory statistical analysis and to geostatistical analysis by means of semivariograms. The areas showed high Ca (>4.0 cmolc dm-3) and Mg (>1.0 cmolc dm-3) levels and localised problems of soil acidity (pHwater <5.5 or V<65%), justifying the carrying out of liming at specific sites. For the geostatistical procedures, the sample grids used at the sites of the Oxisols managed under PA in RS are not efficient in capturing the scales of spatial variability of the attributes pHwater, V%, Ca and Mg, which could compromise the accuracy of corrective prescriptions for specific sites.

Potencial agrícola do uso de resíduo de indústria de carnes em Latossolo Vermelho

The use of non-renewable sources for the production of mineral fertilizers causes major impacts to the environment. The reduction of these impacts favors the increasing search for new organic nutrient sources for crops. This study aimed to evaluate the use of residue from meat industry (RMI) as an alternative source of nutrients for sunflower and maize crops. Five doses of RMI (0 m 3 ha -1 , 25 m 3 ha -1 , 50 m 3 ha -1 , 75 m 3 ha -1 and 100 m 3 ha -1 ) and one treatment with mineral fertilization were tested. The RMI provided an increase in grain yield for the sunflower and maize crops. In the maize crop, the highest yield was obtained with the dose of 87 m³ ha -1 of RMI, equivalent to 92% of the yield obtained with mineral fertilization. In the sunflower crop, doses equal to or higher than 20 m 3 ha -1 of RMI provided equal or higher yields than those obtained with mineral fertilization. The RMI presented agricultural potential for use as an organic fertilizer and can partially or totally replace chemical fertilization.

INFLUÊNCIA DE ECTOMICORRIZAS NO CRESCIMENTO DE MUDAS DE Eucalyptus grandis, Corymbia citriodora, Eucalyptus saligna E Eucalyptus dunnii

The ectomycorrhizal association benefit plants by providing an increase in the area of root absorption and getting more nutrients and water as well as may enable growth of the host soils subjected to adverse conditions. The objective of this study was to evaluate the effect of different ectomycorrhizal isolates on seedling growth of Eucalyptus grandis W. Hill ex Maid., Corymbia citriodora (Hook.) K. D. Hill & L.A.S. Johnson, Eucalyptus saligna Sm. and Eucalyptus dunnii Maiden. The design was completely randomized in a factorial arrangement (4 x 4), four species of Eucalyptus (Eucalyptus grandis, Corymbia citriodora, Eucalyptus saligna and Eucalyptus dunnii ) and four isolates of ectomycorrhizal inoculum (UFSC - Pt116 ( Pisolithus microcarpus (Cooke & Massee) Cunn), UFSC -132 ( Pisolithus tinctorius (Pers.) Coker & Couch), UFSC -121, and without inoculation) with 12 repetitions. Three months after the experiment was evaluated: the percentage of ectomycorrhizal colonization, plant height, stem diameter, number of leaves, dry weight of root and shoot. Relationships were also calculated: dry aerial/root dry mass, height/diameter and Dickson quality index. The plant height, leaf number and shoot dry mass showed higher average in the species Eucalyptus dunnii and Corymbia citriodora , when the inoculation with UFSC -132. Inoculation with UFSC-Pt116 resulted in 63,3 % of colonized roots in Corymbia citriodora , while Eucalyptus dunnii inoculated with UFSC-121 had 67,7 % of its colonized roots. The isolated ectomycorrhizal UFSC-132 provides enhanced growth of seedlings of Eucalyptus dunnii and Corymbia citriodora compared to the control without inoculation.

RESISTÊNCIA À GEADA E CRESCIMENTO INICIAL DE Toona ciliata EM CULTIVOS CONSORCIADOS COM Eucalyptus grandis EM DIFERENTES ADUBAÇÕES

Nutritional restriction and the occurrence of frost in southern Brazil often affects the growth of forest stands. In order to quantify the initial growth and resistance to frost of Toonna ciliata plants, in crops intercropped with Eucalyptus grandis in different fertilization, an experiment was conducted at UFSM, campus Frederico Westphalen, Brazil. The experimental design was a randomized block design with three replications, in factorial 2 x 2 x 3: two forest species ( Eucalyptus grandis Hill ex Maiden and Toona ciliata M. Roem var. australis), two types of stands (single and intercropped) and three types of fertilizer (NPK, NPK + Si and NP slow-release + K + biostimulant). The growth of plant height was measured at different dates, up to 346 days after planting. At the end of this period, it was quantified the diameter at breast height and dry mass of shoots. The assesment of the level of damage to the plants and the degree of resistance to frost was with grading based on the entire plant and tree canopy. The data were submitted to variance analysis and when significant (p ≤ 0.05), we proceeded to compare the treatment by means of Tukey test (p ≤ 0.05). The two forest species were tolerant to frost, but with greater damage to the leaf area in plants Toona ciliata against the Eucalyptus grandis . The cultivation Toona ciliata under protection the Eucalyptus grandis has not diminished the damage to frost in the first year of field deployment. The use of slow-release fertilizer, Si and biostimulant did not contribute to increasing growth and resistance to frost the plants of the two forest species.

Interference from the vertical variation of soil phosphorus and from water stress on growth in maize, the soybean and sunflower

The distribution of phosphorus (P) in the soil interferes with the availability of the nutrient and can affect plant growth. The aim of this study was to compare the growth and accumulation of P in maize, soybean and sunflower plants in vertical gradients of the nutrient in the soil, with and without water stress. The design was completely randomised with five replications, in a 3 x 2 factorial scheme: three soil depth gradients of P (decreasing, increasing and nil) and two conditions of soil water availability (with and with no water stress). The depth gradients of P were in decreasing doses of P2O5 (300, 200, 100 and 0 mg dm-3), increasing doses (0, 100, 200 and 300 mg dm-3) and equal doses (150 mg dm-3) applied to the intermediate layers between 0.0-5.0, 5.1-10.0, 10.1-15.0 and 15.1-20.0 cm. Height, dry weight and P accumulation in the roots and shoots were quantified. The data were submitted to analysis of variance, and mean values compared by Tukey’s test (p<0.05). The distribution of P in the soil did not interfere with growth or nutrient accumulation in the soybean. Phosphate fertiliser located in the surface or subsurface layers favoured greater growth and the accumulation of P in the maize and sunflower, compared to the uniform distribution of the nutrient in the 0-20 cm layer. The increase in phosphate fertiliser at depth did not increase growth or P accumulation in the three crops, even under conditions of water stress.

Amenizante Orgânico e Eucalyptus grandis para Fitoestabilização de Solo Contaminado com Cobre

Este trabalho avaliou a utilizacao de turfa como amenizante e Eucalyptus grandis como tecnica de fitoestabilizacao para remediar solo contaminado com cobre. O trabalho foi conduzido sob delineamento inteiramente casualizado em arranjo fatorial (2 × 6), sendo sem e com adicao de turfa (200 mL L-1 de solo) e seis doses de cobre adicionadas ao solo (0 mg kg-1, 60 mg kg-1, 120 mg kg-1, 180 mg kg-1, 240 mg kg-1, 300 mg kg-1 de solo), com seis repeticoes. Avaliaram-se a altura das mudas, o diâmetro do colo, a massa seca radicular e aerea, a area superficial especifica, os teores e a quantidade acumulada de cobre no sistema radicular e na parte aerea e o indice de translocacao. A adicao de turfa possibilitou efeito amenizante da contaminacao por cobre e favoreceu o crescimento das mudas. As mudas de Eucalyptus grandis apresentam elevado acumulo de cobre nas raizes, o que permite indica-la como promissora para fins de fitoestabilizacao de solos contaminados com cobre.

Uso de Substrato Compostado na Produção de Mudas de Eucalyptus dunnii e Cordia trichotoma

The substrates have influence on germination and growth of forest species seedlings. Aiming to evaluate the germination, growth and quality of Eucalyptus dunnii and Cordia trichotom seedlings on substrates obtained by composting of organic waste we conducted an experiment at UFSM, campus Frederico Westphalen, Brazil. Four substrates composting (university restaurant waste, recycling household waste, liquid cattle manure and flotation process sludge) and commercial substrate (with and without mineral fertilizer) were used. The design was completely randomized with four replications. The substrates influenced the germination rate, but did not affect the final germination percentage. Alternative substrates from waste of university restaurant waste and flotation process sludge provided greater height and diameter of E. dunni and C. trichotoma seedlings and can be used to replace the commercial substrate.

Uso de Substrato Compostado na Produção de Mudas de Eucalyptus dunnii e Cordia trichotoma / Composted Substrate in the Production of Eucalyptus dunnii and Cordia trichotoma Seedlings

The substrates have influence on germination and growth of forest species seedlings. Aiming to evaluate the germination, growth and quality of Eucalyptus dunnii and Cordia trichotom seedlings on substrates obtained by composting of organic waste we conducted an experiment at UFSM, campus Frederico Westphalen, Brazil. Four substrates composting (university restaurant waste, recycling household waste, liquid cattle manure and flotation process sludge) and commercial substrate (with and without mineral fertilizer) were used. The design was completely randomized with four replications. The substrates influenced the germination rate, but did not affect the final germination percentage. Alternative substrates from waste of university restaurant waste and flotation process sludge provided greater height and diameter of E. dunni and C. trichotoma seedlings and can be used to replace the commercial substrate.