The correct nutrition by the occasion of implantation is essential for the increasing and maintaining the productivity of the planted forests and one of the management options used to minimize the effects of variability in productivity is the precision agriculture, which with the use of geostatistical tools aid in the management of the crop and represents an important factor in the economy and more rational employment of agricultural inputs. The aim of this study was to evaluate the influence of liming on the spatial variability of leaf chemical composition (N, P, K, Ca, Mg and S) and at the height of the spontaneous hybrid of Eucalyptus urophylla clone I 144, at six months after planting, in a Quartzarenic Neosol in a low altitude cerrado zone. The experiment was conducted in an area belonging to the Bom Retiro Farm, property of Eldorado Brazil Celulose, between the months of March to September 2014, located in the city of Água Clara, MS. The geostatistical mesh installed in a regular grid for data collection was comprised of 50 points with a sample spacing of 9.0 x 7.5 m. The studied attributes were the plant height and leaf nutrient content (N, P, K, Ca, Mg and S) of the eucalyptus. The data were analyzed by descriptive statistics and spatial variability was determined by geostatistical methods such as calculating the semivariogram and use of interpolated maps by ordinary kriging. The liming had influenced the leaf content of nitrogen, phosphorus, calcium and magnesium of Eucalyptus urophylla clone I 144 and the leaf magnesium was the only attribute that presented spatial dependence, which enables the management located at an early stage.Key words: geostatistics, eucalyptus nutrition, limestone, precision agriculture. INFLUÊNCIA DA CALAGEM NA VARIABILIDADE ESPACIAL DA COMPOSIÇÃO QUÍMICA FOLIAR E NO CRESCIMENTO INICIAL DO EUCALIPTO RESUMO: A correta nutrição por ocasião da implantação é essencial para o aumento e manutenção da produtividade das florestas implantadas e uma das opções de manejo utilizadas para minimizar os efeitos da variabilidade na produtividade é a agricultura de precisão, que com o uso de ferramentas geoestatísticas auxiliam no manejo da lavoura e representa fator importante na economia e emprego mais racional dos insumos agrícolas. O objetivo deste trabalho foi avaliar a influência da calagem na variabilidade espacial da composição química foliar (N, P, K, Ca, Mg e S) e na altura do híbrido espontâneo de Eucalyptus urophylla clone I 144, aos seis meses após o plantio, num Neossolo Quartzarênico em área de cerrado de baixa altitude. O experimento foi conduzido em área pertencente à Fazenda Bom Retiro, propriedade da Eldorado Brasil Celulose, entre os meses de março a setembro de 2014, localizada no munícipio de Água Clara, MS. A malha geoestatística instalada em grade regular para coleta dos dados foi constituída de 50 pontos com espaçamento amostral de 9,0 x 7,5 m. Os atributos estudados foram a altura de planta e os teores foliares de nutrientes (N, P, K, Ca, Mg e S) do eucalipto. Os dados foram analisados pela estatística descritiva e variabilidade espacial foi determinada por métodos geoestatísticos como cálculo do semivariograma e uso de mapas interpolados por krigagem ordinária. A calagem influenciou os teores de nitrogênio, fósforo, cálcio e magnésio foliar do Eucalyptus urophylla clone I 144 e o magnésio foliar foi o único atributo que apresentou dependência espacial, o que possibilita o manejo localizado em estádio inicial.Palavras-chave: geoestatística, nutrição de eucalipto, calcário, agricultura de precisão.

Soil mechanical scarification (MS) and cover crop growing (CC) are strategies to minimize compaction in the soil surface layer under the no-tillage system (NTS). The objective of this study was to evaluate the effects of soil mechanic scarification on the yield and nutrient accumulation in the shoot dry matter of cover crops, as well as the persistence of crop residues in NTS, implemented 12 years ago in the Cerrado conditions with low altitude. The study was carried out in Selvíria, Mato Grosso do Sul state, Brazil, in the 2012 and 2013 harvest, in a clay soil classified as Oxisol Red epi-eutrophic alic. The experimental design was a randomized block arranged in a 5 × 2 factorial scheme, with four replicates. The treatments were constituted by the combination of four cover crops (Cajanus cajan, Crotalaria juncea, Urochloa ruziziensis and Pennisetum glaucum) and fallow with spontaneous vegetation, with or without MS. Soil MS increases the shoot dry matter yield of P. glaucum, U. ruziziensis and C. cajan in the first crop. The P. glaucum species, independently of soil scarification, provide higher yield and accumulation of macronutrients in the shoot dry matter, besides provide higher persistence of crop residues. The U. ruziziensis and C. cajan, independently of soil scarification, have the potential for accumulation of N, P, K and Ca in the shoot dry matter, although with less persistence of residues on the soil surface.

Sample arrangements and spatial variability characterization of dendometrics parameters of...

A silvicultura com espécies exóticas desempenha importante papel socioeconômico no Brasil, fornecendo matéria-prima para a produção de madeira, lenha, carvão e celulose, dentre outros. Nesse sentido, torna-se necessária o aprofundamento do conhecimento sobre as variáveis ambientais que controlam a produtividade do Pinus, em especial, as edáficas. O objetivo do presente trabalho foi avaliar a variabilidade espacial dos atributos químicos de solo e planta em um plantio comercial de Pinus caribaea var. hondurensis. O experimento foi instalado no campus da Faculdade de Engenharia de Ilha Solteira (Unesp), localizado em Selvíria, Estado de Mato Grosso do Sul, Brasil, em um LATOSSOLO VERMELHO Distroférrico, textura muito argilosa. Foram analisados os seguintes atributos químicos do solo: fósforo (P), matéria orgânica (MO), potencial hidrogeniônico (pH), potássio (K), cálcio (Ca), magnésio (Mg), acidez potencial (H+Al), alumínio (Al), soma de bases (SB), capacidade de troca catiônica (CTC), saturação por bases (V%) e, cálcio (CaT), magnésio (MgT) e alumínio (m) na CTC. Pode-se estimar os atributos químicos da camada de 0,10-0,20 m através dos atributos da camada superficial (93%), não sendo, portanto, necessária à coleta dos atributos subsuperficias, representando oportunidades de economia em analises e de coleta de solos para futuros trabalhos. Todos os atributos de solo e planta apresentaram dependência espacial simples na área do estudo, exceto, altura, diâmetro a altura do peito e acidez potencial na camada de 0,10-0,20 m, evidenciando que o manejo de Pinus pode ser realizado de acordo com site especifico nas condições do estudo. O potássio foi o atributo de solo que apresentou cokrigagem com a produtividade de Pinus, bem como os melhores indicadores para a estimativa da produtividade.

Soil compaction and nutrient accumulation on the surface have been a major problem. Soil scarification can alter nutrient variability due to partial soil mobilization. This research aimed to evaluate by multivariate techniques the main chemical attributes of the soil that best relate to soybean yield and production components. The experiment was performed in a dystrophic Red Oxisol, in the agricultural year of 2015/16, in Savannah area located in the Selvíria County, MS, Brazil. The experiment consisted of two cultivated areas, one under no-tillage system (NTS) implemented 13 years ago and another in minimum cultivation system scarified (MCSS). Were evaluated: population of plants, first pod insertion height, plant height, the number of pods per plant, grain per plant, grain per pod, the weight of 100 grains, grain yield and soil chemical attributes. Soybean yield was higher in NTS when compared to MCSS scarified. The values of pH, calcium content, magnesium and phosphorus in the layer of 0-0.10 m, as well as the content of K in 0.10-0.20 m, are the attributes that most contributed to the increase of soybean productivity in NTS and MCSS.

Soil compaction in no-tillage systems (NTS) affects the sustainability of this management. To overcome the problem, mechanical chiseling and maintenance of the vegetation cover suggested were as management practices in order toreestablish ideal cultivation conditions. The soil studied was occupied for 20 years with annual crops in conventional tillage system (plowing and leveling harrow). After, the NTS was implemented for 15 years old. In 2012, management were implemented to study the effects on soil quality, with mechanical chiseling, cover crops, rice and bean. Thepurpose of this study was to evaluate the effect of soil chiseling and the use of cover crops on the maintenance of NTS sustainability after a crop succession of rice and common bean on a clayed Orthic Ferralsol. After four years we evaluation were then carried out to analyze the effects of the system on the soil quality physical and chemical attributes. We studied five cover plants (Crotalaria juncea; Cajanus cajan; Pennisetum glaucum; Urochloa ruziziensis and Fallow) all in NTS with and without chiseling. In addition, we studied a natural Savannah fragment too. Chiseling with cultivation of Crotalaria juncea as vegetation cover improved the physical properties compared with the initial conditions. However, cover crops grown on unchiseled soil resulted in an increase in the chemical properties P, K, and Mg concentrations, pH, and soil organic matter. The soil nanostructures morphological characteristics is a promising indicator it quality, complementary to the chemical indicators, for being sensitive enough for the short-term detection of changes soil properties.