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Santos O.S.N.,Nucleo de Engineering de Agua e Solo | Teixeira M.B.,UFRB
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

In this study the growth and nutritional status of helicônias irrigated with treated wastewater of domestic origin associated with chemical fertilizers (NPK) was studied. The experiment was conducted in a greenhouse utilizing plants of helicônia Golden Adrian. The experiment was installed in 5 x 3 + 1 factorial scheme consisting of five depths of irrigation water (equivalent to 60, 80, 100, 120 and 140% of class A pan evaporation - ECA), three types of water (wastewater (AR), rainwater (AP) and a mixture of 50% AR + 50% AP) and control (soil without fertilizer and receiving rainwater corresponding to 100% ECA). The experimental design was in randomized blocks with five repetitions. The use of AR and larger depths of irrigation provided increases in evaluated parameters of growth. The levels of macronutrients in the leaves of plants irrigated with AR were similar to plants that received AP. The use of AR and AP resulted in increases in the content of micronutrients in leaves, especially Fe and Mn, above the levels recommended for the crop.

Thebaldi M.S.,Centro Universitario Of Formiga Mg | Lima L.A.,Federal University of Lavras | De Almeida W.F.,Nucleo de Engineering de Agua e Solo | Andrade R.R.,Federal University of Viçosa
Engenharia Agricola | Year: 2016

For drip irrigation design and management, it is necessary to know the relation between flow and pressure acting on emitters. In the case of subsurface drip irrigation, the backpressure phenomenon may change the hydraulic characteristics of emitters. Thus, this study aimed at determining such relationship between flow and pressure of different driplines in surface and subsurface conditions; aiming to find possible differences in hydraulic behavior. We tested four emitter types; two pressure compensating (D5000 and Hydro PCND) and two non-pressure compensating (TalDrip and Jardiline). Emitter flow rates were attained in atmospheric conditions and submerged in water, in which submergence levels represented backpressure. Assays were performed using inlet pressures of 80, 100, 120, and 150 kPa for the Hydro PCND dripline and 25, 50, 100, and 150 kPa for the other ones; the backpressures were of 0.49, 1.47, 2.45, 4.41 and 6.37 kPa with four replications. The emitters had their proportionality constants and discharge exponents changed in submerged applications, representing backpressure effect. Non-pressure compensating emitters had their discharge exponent decreased, while in pressure compensating ones, it was increased. Backpressure reduced emitter flow rates at all evaluated pressures.

Sousa A.E.C.,Federal University of Campina Grande | de Lacerda C.F.,Federal University of Ceará | Gheyi H.R.,Nucleo de Engineering de Agua e Solo | Soares F.A.L.,IF Goiano | Uyeda C.A.,IF Paraiba
Revista Caatinga | Year: 2012

Aiming to evaluate gas exchange and concentration of macro and micronutrients in leaves of physic nut grown under saline conditions, an experiment was conducted in protected ambient adopting a randomized block design in factorial scheme combining five levels of irrigation water salinity ECw (0.6; 1.2; 1.8; 2.4 and 3.0 dS m-1) and two levels of phosphorus (135 and 200 g plant-1) and with four replications. Each plant was grown in pots with a capacity of 200 L. The gas exchange rates (leaf temperature, transpiration, stomatal conductance and photosynthesis) were obtained using a portable photosynthesis meter (IRGA), in the fourth expanded leaf from the apex of the plant. To determine the nutrient content of the plant, the limbo located between the fourth and fifth leaf below the inflorescence was used. The determination of nutrients followed the methodology described by Silva (1999). It was found that the salinity level of irrigation water affected the variables of gas exchange and accumulation of the minerals which has following sequence: K > N > Ca > Cl > Na > Mg > P > S > Fe > Mn > Zn > Cu. With the exception of copper all evaluated nutrients and increased with increasing salinity of irrigation water. The lowest dose of P2O5 used was sufficient to allow the development of the plant during the experimental period, there was no effect of its increase in photosynthetic parameters evaluated.

The population growth not only demands further exploration and use of water, but generates different types of wastewater, such as sewage which is dumped directly into watercourses. In this context, the aim of this study was to evaluate the influence of the use of wastewater from domestic sources on the growth of plants of physic nut during the third year of production under protected ambient. A randomized block design in a 5 × 2 factorial scheme was used, the factors being five levels of water replacement - WR (0.25, 0.50, 0.75, 1.00 and 1.25 times water consumed by the plant) and two levels of phosphorus (135 and 200 g plant-1 year-1) with four replications. Plants were grown in recipients with a capacity of 200 L and in the beginning of the 3rd year of production (present study) a drastic pruning was performed. The variables plant height, stem diameter; leaf number and leaf area of the physic nut were influenced by the depth of water replacement from 30 days after pruning (DAP). The leaf number and stem diameter were affected by phosphorus dose at 30 and 90 DAP, respectively. The plant height and leaf area were influenced by the interaction (WR × phosphorus dose) at 30, 60 and 90 DAP. The weight of the fruit and water use efficiency of physic nut were affected by the depth of water applied but were not influenced by phosphorus dose.

Vilela M.S.,Instituto Federal Goiano | Filho F.R.C.,Instituto Federal Goiano | Teixeira M.B.,Instituto Federal Goiano | Amaral A.M.,IFNMG | Vellame L.M.,Nucleo de Engineering de Agua e Solo
IRRIGA | Year: 2015

To apply a blade of adequate irrigation is necessary to know the crop water demand, estimating precisely its evapotranspiration for efficient irrigation management. The evapotranspiration of culture can be determined precisely by the use of electronic or mechanical weighing lysimeters. The objective of this study was to development and calibration of a mini-lysimeter mechanical weighing low cost for the determination of the reference evapotranspiration. The mini-lysimeter consists of a PVC tank, resting on fixed metal shields, with a drain at the base of the tank, the load cells (four cells) are derived from a domestic weighing balance. The system acquisition and storage of data using a micro-controller. For calibration of the lysimeters was used reference masses consisting of 4 units (10, 5, 0.5 and 0.2 kg) were added in increasing and decreasing order in 5 measuring cycles in order to obtain the calibration curve of equipment. Were calculated the maximum absolute error, repeatability errors, linearity and hysteresis of the instrument. There has been a trend in deviations from the applied resulting mass calibration, the higher the maximum applied load (35.7 kg), with a value of -1.52 kg. The non-linearity error it was what influenced more in accuracy of the mini-lysimeter with 1.68 kg and 7.93 of influence in the measurement, us cycles of loading and unloading, respectively. The Hysteresis showed low interference in the measurement, 0.06%. The maximum absolute error showed a high value of 1.5 kg (0.35%), requiring new settings on your hardware and load cells. © 2015, Universidade Estadual Paulista - UNESP. All rights reserved.

Terceiro Neto C.P.C.,Extencionista da EMATER PB | Medeiros J.F.,Rural University | Gheyi H.R.,Nucleo de Engineering de Agua e Solo | Dias N.S.,Rural University
IRRIGA | Year: 2014

Rio Grande do Norte state is the second largest exporter of melons in Brazil, and the scarcity of water of good quality has limited the expansion of irrigated areas in the Mossoró region, in which the major part of their production is concentrated. However, the high availability of saline water of low cost could be feasible if appropriate management was carried out. The objective of the study was to evaluate the effects of low and high salt concentrations in water, applied on an alternate basis, on growth and mineral composition of leaf tissue of melon plant. The experiment was conducted in Pedra Preta farm, Mossoró city, RN. Melon plants (Cucumis melo L., cv Sancho) were irrigated with low (CEa = 0.5 dS m-1) and high (ECw = 4.3 dS m-1) salinity water applied daily, on an alternate basis, according to the growth stage or with no crop alterations, totaling 10 treatments. Randomized blocks with four replications were used in the experimental design. The management strategies had no effect on dry phytomass accumulation in melon plants. The increased uptake of K by the melon tissue contributed to a high K/Na ratio in the shoots, which confirms the salinity tolerance of this cultivar.

de Sousa C.H.C.,Federal University of Ceará | de Lacerda C.F.,Federal University of Ceará | da Silva F.L.B.,Federal University of Ceará | Neves A.L.R.,Federal University of Ceará | And 2 more authors.
Engenharia Agricola | Year: 2014

The objective of this study was to evaluate the use of subsoiling, gypsum and organic matter associated with the cultivation of cotton, sunflower and cowpea in crop rotation, seeking the reclamation and use of a saline-sodic soil. The treatments were arranged in a randomized block design in split plots with four replications, during two crop cycles (2009/2010 and 2010/2011). The plots were formed by the treatments: T1. Subsoiling (S); T2. S + 20 Mg ha-1 of gypsum T3. S + 40 Mg ha-1 of organic matter; T4. S + 10 Mg ha-1 of gypsum + 20 Mg ha-1 of organic matter; T5. S + 20 Mg ha-1 of gypsum + 40 Mg ha-1 of organic matter and the sub-plots consisted of the cotton-cowpea (C/CP) and sunflower-cowpea (S/CP) crop rotation. The use of gypsum and organic matter contributed to decrease the soil salinity and sodicity. Cotton was not affected by the treatments, while the sunflower crop was favored by the application of amendments only in the second production cycle. Higher yields of cowpea in T5 treatment, during the 2009/2010 cycle, are indicative that higher doses of gypsum and organic matter applied in this treatment accelerate the reclamation process. For other treatments with amendment application there was a beneficial effect for this crop only in the second cycle, when the values of productivity were similar to T5.

Guedes Filho D.H.,Federal University of Campina Grande | dos Santos J.B.,Federal University of Campina Grande | Gheyi H.R.,Nucleo de Engineering de Agua e Solo | Cavalcante L.F.,Federal University of Paraiba | Santos Junior J.A.,Federal Rural University of Pernambuco
IRRIGA | Year: 2015

The use of brackish water in irrigation and soil fertilization with nitrogen has contributed to the expansion of sunflower cultivation. In this context, the components of production and yield of sunflower plants (Helianthus annuus L.) cv. EMBRAPA 122/v-2000 were evaluated under different water salinity levels (ECw) and Nitrogen doses. The experiment was conducted at the municipality of Remígio, Paraíba from November 2011 to February 2012. Treatments were allocated in randomized blocks in a split-plot and factorial (5 x 4) design. Levels of saline irrigation water – Ecw 0.15; 1.5; 2.5; 3.5 and 4.5 dS m-1 were the plots and doses of Nitrogen 40; 60; 80 and 100 kg ha-1 were the subplots with three replicates and 30 plants per plot. The productivity in achenes, oil yield, dry and fresh biomass of the chapter of sunflower decreased linearly with water salinity and increased linearly with Nitrogen doses. Dry matter of the chapter without achenes suffered no influence from doses of Nitrogen, but it was affected by increasing water salinity levels. A significant effect of interaction between water salinity levels and Nitrogen doses was found on the diameter of the chapter and drymass of chapter with achenes. A negative linear effect of water salinity levels and positive linear effect of doses of Nitrogen fertilization were observed on both variables. © 2015, Universidade Estadual Paulista - UNESP. All rights Reserved.

Santos Junior J.A.,Federal Rural University of Pernambuco | Gheyi H.R.,Nucleo de Engineering de Agua e Solo | Cavalcante A.R.,UFRB | Dias N.S.,UFERSA | Medeiros S.S.,Nucleo de Recursos Hidricos
Engenharia Agricola | Year: 2016

In view of the specific characteristics regarding infrastructure, soil, climate, hydrology and social conditions of the Brazilian semi-arid, it is of paramount importance the use of alternative cropping systems, which take into account such features, as well as considering local water quality. In this sense, our study aimed to evaluate saline stress effects on sunflower production and post-harvest which are grown in an alternative low-cost hydroponics. Experimental design consisted of completely randomized blocks in 4 × 3 factorial scheme, with three replications. Treatments assessed the effect four salinity levels in hydroponics nutrient solution (1.7 - control, 4.3, 6.0, and 9.0 dS m-1) on crop production of three sunflower cultivars ('Sol Noturno', 'Bonito de Outono', and 'Anão de Jardim'). Our results showed that even at a maximum salinity level in nutrient solution (9 dS m-1), number of petals postharvest life remained within commercial standards for both 'Sol Noturno' and 'Anão de Jardim' cultivars.

de Araujo A.P.B.,DeNA | Costa R.N.T.,DeNA | de Lacerda C.F.,DeNA | Gheyi H.R.,Nucleo de Engineering de Agua e Solo
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2011

The objective of the present study was to evaluate on the basis of profitability indicators, the economic viability of the reclamation processes of a sodic soil located at the Irrigated Perimeter Curu-Pentecoste, CE, relating the reclamation cost with the gross revenue obtained from the cowpea. The experimental design was a completely randomized block with five treatments and five replications. The reclamation treatments were T 0: control, T 1: 40 t ha -1 of organic matter (OM), T 2: 20 t gypsum ha -1, T 3: 20 t ha -1 gypsum + 40 t ha -1 MO, T 4: 10 t ha -1 gypsum + 20 t ha -1 MO. The profitability indicators were analysed through an "ex-ante" and an "ex-post" evaluation forms, considering the costs and/or investments on the sodic soil reclamation and the installation of an underground drainage system. The cowpea yield contributed only with 12% of the reclamation costs of the sodic soil. From a strictly financial point of view, and considering the alternative of applying only one soil amendment, the gypsum appeared as the most attractive alternative. The reclamation process showed a good economic viability with an interest rate of 12% per year and high economic viability with a rate of 6% per year, demonstrating the necessity of a creation of a policy of subsidized credit as a way to incorporate the extensive areas of degraded sodic soil to productive process.

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