Resumo Desenvolveu-se estudo em lote de vale aluvial irrigado por microaspersão e cultivado com cenoura (Daucus carota L.), no início da estação chuvosa, onde existe risco de salinização, associado à qualidade das águas subterrâneas utilizadas para irrigação. O desempenho do manejo de irrigação com água salina (CE = 1,38 dS m-1) foi avaliado com base em lavagem parcial de sais, na manutenção de níveis adequados de umidade e de salinidade no perfil. Verificou-se redução da condutividade elétrica no perfil 0-100 cm durante o cultivo, principalmente na zona radicular. Simulação numérica de fluxo e transporte de sais foi, então, realizada, tendo-se reproduzido adequadamente as medições de campo, com relação às tensões do perfil e ao conteúdo de sais. Verificou-se, através de modelagem, que a alternativa de lixiviação incompleta apresentou desempenho adequado, quando comparada com a lixiviação completa, baseada na salinidade da água de irrigação e na tolerância da cultura.

Medidas diretas de evapotranspiração de referência são importantes na avaliação e na calibração de métodos indiretos. Avaliou-se o desempenho de lisímetro de pesagem hidráulica de baixo custo, visando à determinação direta da evapotranspiração de referência (ETo), em área de assentamento rural no Semi-Árido nordestino. O lisímetro é de concepção simplificada, com travesseiros hidráulicos confeccionados com mangueira flexível de butil e revestida em náilon, interligados a um sistema manométrico com mercúrio e água. O equilíbrio do lisímetro foi estável, sendo o maior erro médio posicional de 3,93%. As calibrações geraram coeficientes de correlação superiores a 0,9993 e resoluções de leituras entre 0,095 e 0,134 mm. As leituras lisimétricas foram comparadas com estimativas da ETo obtidas, utilizando-se dos métodos de Penman-Monteith, Blaney-Criddle-FAO, Jensen-Haise e do Tanque Classe A-FAO. Adicionalmente, avaliou-se o desempenho de um tanque evaporimétrico simplificado, construído a partir de material reciclado, o qual vem sendo utilizado no manejo da irrigação em áreas de agricultura familiar. Todos os métodos analisados apresentaram bom desempenho, com medidas bem correlacionadas aàs do lisímetro, para o período estudado.

Este trabalho foi realizado em um vale aluvial irrigado do semiárido do Brasil (Estado de Pernambuco). O objetivo foi investigar o efeito de lâminas de lixiviação e de precipitação no controle da salinidade do solo em lisímetros de drenagem. Com base em simulações numéricas, utilizando-se do modelo HYDRUS-1D, avaliaram-se o fluxo e o transporte de sais na zona não saturada. Mediante medidas de campo de evapotranspiração real e precipitação, foi possível inferir que o modelo se apresentou como ferramenta adequada nas simulações realizadas, para diferentes cenários de lâminas de lixiviação. Verificou-se, experimental e numericamente, que a lixiviação parcial pode ser utilizada como alternativa de manejo para a redução da salinidade na zona radicular, desde que precipitações efetivas possam complementar o processo de lavagem.

ABSTRACT Efficient water use in agriculture is fundamental, especially in semi-arid regions where water scarcity is intense. The aim of this study was to estimate water requirements and crop coefficients in the different phenological stages of Moringa oleifera. The experiment was carried out from February to April 2015 at the Experimental Unit for Reuse and Hydrological Management, located in Mutuca, PE (7º 15’ 18’’ S, 35º 52’’ 40’’ W, 550 m). A lysimeter was used to estimate crop evapotranspiration. Reference evapotranspiration (ETo) was estimated by indirect methods. In the lysimeter, soil salinity and leaf water potential of the crop were monitored. The direct and indirect methods presented an excellent performance compared with the standard grass-lysimeter, especially Hargreaves-Samani, which presented a remarkable result for the study area. Crop coefficients (Kc) ranged from 0.73 to 1.73 in the different phenological stages. Moringa crop evapotranspiration (ETc) exhibited temporal variations, with a cumulative rate of 139.8 mm, for a cumulative reference evapotranspiration of 130.97 mm. Moringa plants showed slight water restriction, at the times of lower solar radiation.

In areas where there is irrigated agriculture, the recuperation of water reserves in alluvial aquifers may occur preferentially due to precipitation. Recharging can be evaluated from variation information of water depth measured in piezometers or observation wells. Thus, the aim of this research is to study the recharge in the alluvial aquifer formed by the Mimoso temporary stream in the semiarid region of Pernambuco (PE), Brazil, using the method of the fluctuation of the water level. This system is typical on the Brazilian Northeast semiarid region, using groundwater for domestic supply and for irrigation on small scale agriculture. Monthly potentiometric levels and rainfall data were used. The selected period for the study, from January 2002 to October 2009, involved extreme events of flooding and droughts as well as regular years, providing a better understanding of the behavior of the alluvial recharge. It was found that the system responds significantly to precipitation events. It was also observed that even with different soil textures in the study area, recharge factors were not significantly different. The study provided a better understanding of the behavior of aquifer recharge and its relationship with the soil and the rainfall events in the region.

ABSTRACT Spatial variability analysis of meteorological elements and precise identification of possible causes of thermal stress in poultry housing help producers in the decision making process. The objective of this study was to evaluate the internal environment of poultry houses in the downtime (sanitary void) and in the production phase, to characterize spatial thermal variability and to identify critical control points. The study was carried out in the Alluvial Valley of the Mimoso River, municipality of Pesqueira, PE, Brazil. The data of air temperature, wind speed and illuminance were recorded in November (spring season), at 155 points within each poultry facility (10 x 90 m), spaced in a 3.0 x 2.5 m grid and subjected to descriptive statistical analysis and geostatistics. There was a strong spatial dependence for the variables air temperature, wind speed and illuminance. The ranges obtained for the air temperature in the facilities were from 48.22 to 114.52 m, while for the wind speed and illuminance were less than 10 m, thus revealing the need for greater homogeneity of the studied variables and meeting of the thermal requirement of the poultry.

ABSTRACT Soil moisture is essential for agricultural production. Knowledge on its spatial-temporal variability is indispensable to support agriculture, and it is strongly influenced by cultural practices, soil cover conditions and irrigation methods. Thus, this study aimed to evaluate the temporal stability and spatial distribution of soil moisture as a function of the use of banana leaves as soil cover in a plot under conventional sprinkler irrigation and cultivated with banana in the Brazilian semiarid region. The study area was divided in two sectors, with and without covering using banana leaves. Soil moisture was monitored before and after irrigation, at 16 times, using FALKER HidroFarm sensors installed on a transect with 11 units spaced by 8 m, in each sector. The data were analyzed using descriptive statistics, temporal stability and Spearman correlation test. The morphology of the banana leaves and the irrigation system used contributed to lower soil moisture in the covered sector at all monitoring times. Variations in the physical-hydraulic properties of the soil promoted variations in soil moisture with the position of the sensors in the ground. The temporal stability technique allowed the identification of points that represent the mean behavior of soil moisture throughout the area. The use of banana leaf residues caused less soil wetting using sprinkler irrigation, indicating the need to pre-grind the material or use localized irrigation systems, practices that are not very accessible to small farmers.

ABSTRACT The objective of the present study was to characterize the spatial and temporal (2000-2015) rainfall pattern variability and erosive potential in the different physiographic regions of the state of Pernambuco, Brazil. Rainfall data series (3 to 12 years) from 25 weather stations of the state were analyzed. Erosive rainfall events (more than 10 mm depth) were considered to evaluate the annual erosivity index, monthly erosivity index (EI30), rainfall erosivity factor (R), and rainfall pattern. The inverse distance weighting (IDW) - inverse of the square of the distance - was used to create spatial interpolation and develop maps. The rainfall data from the weather stations showed average annual rainfall of 827 mm and average erosivity of 4,784 MJ mm ha-1 h-1. The Metropolitan region of Pernambuco presented the highest rainfall erosivity index, with annual average of 9,704 MJ mm ha-1 h-1; and the Sertão do São Francisco region had the lowest, with annual average of 4,902 MJ mm ha-1 h-1. The state of Pernambuco presented advanced (42%), intermediate (38%), and delayed (20%) rainfall patterns.

ABSTRACT This study evaluated the influence of three plant species and two periods on the amount of carbon stored in the substrate in an extensive green roof. The study was carried out in March and September 2020 at Charles Darwin Business Garage Building, Recife, Pernambuco state, Brazil. A completely randomized design with a split-plot scheme was adopted, with plant species (zoysia grass [Zoysia japonica], inch plant [Tradescantia zebrina], and fountain grass [Pennisetum setaceum]) allocated to plots and the material collection periods (March and September) to subplots. The CO2 and organic carbon concentrations in the substrate were quantified. Thirty samples were obtained from the substrate during each period. No statistically significant difference was observed in CO2 content among species treatments; however, there was a significant difference between the two periods evaluated, with average values of 14.05 and 96.97 mg in March and September, respectively. Therefore, September has the greatest potential for CO2 storage in the substrate. Significant differences were observed in organic carbon concentrations among species and between periods, with average values of 95.05 and 129.22 g kg-1 for fountain grass and inch plant, respectively, and 131.15 and 100.81 g kg-1 in March and September, respectively.

Resumo O reúso de águas residuárias para irrigação, quando conduzido corretamente, pode poupar considerável volume de água de boa qualidade. Realizou-se experimento em casa de vegetação, considerando como tratamentos quatro tipos de água de irrigação (água de abastecimento, água com fertilizante, efluente de esgoto e efluente de esgoto modificado com KCl a 0,1 mol L-1), e dois solos (Gleissolo e Argissolo), cultivados com milho (Zea mays). A unidade experimental foi constituída de 32 colunas de PVC de 200 mm de diâmetro e 1,0 m de altura. O impacto do reúso sobre as características químicas do lixiviado, e o risco de contaminação do lençol freático foram avaliados. Foram constatados níveis de nitrato, condutividade elétrica (CE) e sódio no lixiviado oriundo do Argissolo significativamente superiores àqueles do Gleissolo, o que limita o potencial dos Argissolos para suporte à disposição controlada de efluentes domésticos, especialmente em regiões sujeitas a lençol freático raso.