Jorge Luiz Moretti de Souza

Calibração de modelos agrometeorológicos para estimar a produtividade da cultura do trigo, considerando sistemas de manejo do solo, em Ponta Grossa-PR

The objective of this work was to evaluate hydric relations and the performance of simplified and agrometeorological models to estimate the productivity of wheat crop, considering four tillage soil systems, in Ponta Grossa, Parana State. The soil type at the experimental area has been classified as Typic Hapludox and the climate of the region classified as Cfb type, according to Koppen climatic classification. The yield data of wheat crop (five seasons) and meteorological were supplied by the ABC Foundation and SIMEPAR, respectively. The tested models are based on the crop yield potential and the ER/ETc relation (actual / crop evapotranspiration), determined by daily water balance occurred during different growth stages. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith method. Considering the numerous tests carried out, the Jensen model show the best estimates of productivity, using yield response factor obtained by multiple regression.

Ajuste de modelos de produção água-cultura para cana-soca

Sugarcane (Saccharum spp.) is one of the main products in the Brazilian agribusiness. In the Paraná State, sugarcane occupies an area of 665,000 ha, with an annual production of about 50 million tons. The Paranavaí region accounts for 20 % of this production, and the planted area is increasing fast in this region (Paraná 2015). Agriculture is the economic activity that has a higher dependence on weather conditions, which are responsible for the oscillations of agricultural seasons (Souza 2014). Environmental factors directly affect plant growth and development. However, the relations between climatic parameters and agricultural production are quite complex. The influence of climate on sugarcane is remarkable because it is a semiperennial crop, grown under different environmental conditions, causing production variations over the years (Silva et al. 2008). ABSTRACT RESUMO

Contraste entre duas metodologias de determinação do potencial agrícola das terras nas vilas rurais no município de Rio Negro, Estado do Paraná

The objective of this work was to analyze the agricultural potential of land in two rural villages, located in Rio Negro, Parana State , Brazil, using two methodologies denominated Land Use Capability (SCU) and Land Agricultural Aptitude (SAA). The rural villages were chosen for their distinct characteristics of soil and slope conditions. The contrast between the methodologies was based on the land limiting factors as well as on the social factors involved in the family settlement in small farms. The results showed that: (a) the SAA was more appropriate than SC U for determining the agricultural potential of the lands; (b) the SAA and SC U indicate that the lands of the two villages do not feature the agricultural potential for annual cultivations; (c) the SC U was more restrictive on the agricultural potential of the land than the SAA.

Water balance output components are distinctly regulated by precipitation and evapotranspiration in Pinus taeda L. plantations in Southern Brazil

The knowledge about the impact of climate variables on estimated water balance hold significant promise for the estimation of critical periods of soil water deficit or surplus. Here we establish the functional relations between water deficit, water surplus and soil water storage with precipitation and evapotranspiration for Pinus, in Southern Brazil. For that purpose a 31-years daily data series of precipitation (P) and reference evapotranspiration (ETo) were used as input components of the modified Thornthwaite and Mather water balance model. Principal component analysis was performed as an exploratory analysis of the water balance components related to P and ETo. The water deficit was mostly affected by the seasonality of evapotranspiration depending on soil water availability. The sole effect of P on water surplus (WS) determined its variability and showed the possible use of P to estimate WS. Soil water storage was not directly influenced by P or ETo.

ATRIBUTOS FÍSICOS E BALANÇO HÍDRICO DO SOLO COM FLORESTA OMBRÓFILA MISTA, EM LATOSSOLO VERMELHO-AMARELO, EM TELÊMACO BORBA - PR

The objective of this study was to characterize the soil physical and hydric attributes and quantify, in one year, the water balance components, carried out for Native Ombrophylous Forest, in an OXISOL, sandy texture, in Telemaco Borba - PR state. The experiment was held at Monte Alegre Farm, which belongs to the company Klabin Florestal, the area was under native forest in an advanced state of regeneration. The following physical and hydric attributes were characterized: bulk density, saturated hydraulic conductivity, soil water retention curve, aeration porosity and total available water ( TAW ). The undisturbed samples were collected in a trench, in five depths. The disturbed samples were collected weekly, in eight different points inside the experiment area, in five depths. The values of soil moisture and internal precipitation were collected and registered throughout the year. The soil water storage was calculated using the trapezoidal rule. The internal drainage and capillary rise were estimated by using the Darcy-Buckingham equation. The values of the bulk density, micro, macro and total porosity of the soil are classified in the range considered adequate for soils with sandy texture. The soil presented a high hydraulic conductivity, which is a characteristic of well drained soils. In average, the storage did not reach the permanent wilting point throughout the year. The average deep drainage was bigger throughout the months with more precipitation, the value being an average of 94.9 mm year –1 . The average value of the real evapotranspiration was 1355.9 mm year - 1 , an average of 3.7 mm day - 1 .

Expanding the geography of evapotranspiration: An improved method to quantify land-to-air water fluxes in tropical and subtropical regions

The development of new reference evapotranspiration (ETo) methods hold significant promise for improving our quantitative understanding of climatic impacts on water loss from the land to the atmosphere. To address the challenge of estimating ETo in tropical and subtropical regions where direct measurements are scarce we tested a new method based on geographical patterns of extraterrestrial radiation (Ra) and atmospheric water potential (Ψair). Our approach consisted of generating daily estimates of ETo across several climate zones in Brazil–as a model system–which we compared with standard EToPM (Penman-Monteith) estimates. In contrast with EToPM, the simplified method (EToMJS) relies solely on Ψair calculated from widely available air temperature (oC) and relative humidity (%) data, which combined with Ra data resulted in reliable estimates of equivalent evaporation (Ee) and ETo. We used regression analyses of Ψair vs EToPM and Ee vs EToPM to calibrate the EToMJS(Ψair) and EToMJS estimates from 2004 to 2014 and between seasons and climatic zone. Finally, we evaluated the performance of the new method based on the coefficient of determination (R2) and correlation (R), index of agreement “d”, mean absolute error (MAE) and mean reason (MR). This evaluation confirmed the suitability of the EToMJS method for application in tropical and subtropical regions, where the climatic information needed for the standard EToPM calculation is absent.

Sazonalidade e potencial energético da biomassa residual agrícola na região dos Campos Gerais do Paraná

Teve-se por objetivo, neste trabalho, avaliar as disponibilidades sazonal e espacial da biomassa residual da colheita das principais culturas de graos, na regiao dos Campos Gerais, PR, estimar o potencial teorico de producao de energia eletrica a partir desses residuos, bem como identificar os municipios da regiao com maior potencial para instalacao de termeletricas movidas a biomassa. Dados de produtividade de milho, soja, trigo, cevada, aveia branca e aveia preta foram obtidos, na Secretaria de Agricultura do Parana, para as safras 2008/2009 e 2009/2010 e, a partir do indice e do calendario de colheitas, estimou-se a producao e sazonalidade da biomassa residual das culturas analisadas. Foram coletadas amostras de biomassa destas especies e determinou-se o poder calorifico superior (PCS) e o potencial teorico de producao de energia eletrica a partir dos residuos quantificados. Os Campos Gerais do Parana produziram 3.862.130 (2008/2009) e 4.107.932 Mg ha−1 (2009/2010) de biomassa residual total com o cultivo das seis culturas. A disponibilidade de biomassa concentra-se em marco e abril (aproximadamente 60%), sendo inexpressiva em dezembro, janeiro e entre junho e agosto. A biomassa residual da colheita de graos apresentou PCS comparavel ao de especies florestais e potencial total de producao de energia de 3.932 (2008/2009) e 4.185 GWh ano−1 (2009/2010). Dos municipios analisados, Tibagi e Castro sao os mais promissores para a instalacao de termeletricas movidas a biomassa, por apresentarem maior producao e melhor distribuicao sazonal dos residuos.

Cultivo de Stenachaenium megapotamicum em diferentes regimes de irrigação

Water rational use for garden irrigation is a constant concern in view of it waste, because researches have shown that it corresponds to 40 to 70% of the domestic consumption. One of the strategies employed to avoid this waste is the selection and planting of drought stress resistant plants. This research aimed to evaluate the Stenachaenium megapotamicum growth, a sub shrub plant, with ornamental potential, native from South Brazil, grown under different water regimes. Two experiments were developed: a) during the spring by applying three irrigation frequencies: daily, every other day, and every three days, b) during the fall / winter by applying four irrigation frequencies: daily, five, seven and nine days. Results obtained showed that S. megapotamicum is an adequate annual plant summer for landscape projects focusing in the efficient water use.

Relações funcionais entre precipitação provável e média em regiões e climas brasileiros

The objective of this work was to determine the statistical parameters of the probability density function (PDF) with the best fit to the values of decennial rainfall observed in several Brazilian localities, and also to determine the relationship between probable rainfall (75% probability, P75%) and average rainfall () in these localities. Five PDFs were evaluated (normal, triangular, gamma, exponential, and uniform), adjusted to data from 43 municipalities, from eight states, in four Brazilian regions. The localities were evaluated singly or grouped into states or climate types. The Kolmogorov‑Smirnov adherence test was used to assess the statistical adjustment of the PDFs to the data series. Gamma and exponential distributions were the ones which more often had the best fit to the series of decennial rainfall (41.2 and 30.8%, respectively). The most promising functional relationships between and P75% were obtained at the climates Cwa (R2 = 0.82), Aw (R2 = 0.70), As (R2 = 0.68), and Cwb (R2 = 0.62), and at the states of Goias (R2 = 0.80), Sao Paulo (R2 = 0.76), and Minas Gerais (R2 = 0.70). The normal (19.3%), triangular (2.2%), and uniform (3.5%) distributions have the lowest participation in the best fits, but are important in the dry season analyzes.