Water application uniformity and fertigation in a dripping irrigation set

The purpose of this study was to evaluate the uniformity of distribution coefficient (UDC) and coefficient of variation (CV) of a familiar set of irrigation, classifying it the ASAE standard. The irrigation and fertigation are determined by two methods the KELLER & KARMELI and DENÍCULI . The two experiments were subjected to varying pressures: 12, 14, 16 and 18 kPa, in a completely randomized design of twenty samples composed of flows with three replications. Urea, potassium chloride (KCl) and ammonium phosphate (MAP) were the elements used for fertigation. The system consisted of a 200 L tank, which supplied another container of 30 L, it was moved vertically to control the pressure. The data was statistically compared between treatments for each methodology. In fertigation the best pressure was 16 kPa and was classified as "excellent" for UDC (91.03%) and "marginal" for C.V. (7.47%). For the irrigation treatment, the best pressure was 16 kPa rated "excellent" for UDC (91.2%) and "marginal" for C.V. (7.68%). The DENÍCULI et al. (1980) methodology proved more reliable for the evaluation of drip systems. It was observed that this set has good uniformity of distribution, but with great variability in flows.

Initial development of two eucalyptus hybrid submitted to irrigation

The eucalyptus offers several advantages compared to other forestry species and, by using the irrigation can increase productivity and decrease production time. The objective of the present study was to evaluate two hybrid eucalyptus (Grancam and Urograndis), no irrigation, dripping and micro sprinkler irrigated at 90, 120, 150 and 180 days after transplanting (DAT). The experiment was conducted at the experimental irrigation area in the State University of Mato Grosso do Sul, in the municipality of Aquidauna - State of MS, Brazil. The experimental design was randomized blocks, split plot with four blocks and two replications within each block, and the plots were composed by irrigation treatments (dripping, micro sprinkler irrigate and dry) and the subplots the hybrids (Grancam and Urograndis).The total area of the experiment had 3 hectares, where each plot consisted of 1 ha. It was evaluated plant height, stem diameter and canopy, stem basal area, the relationship between height and stem diameter, the relationship between height and canopy diameter and stem volume. Data were subjected to analysis of variance and compared by Tukey test at 5% probability. Irrigation systems and dripping sprinkle provide greater plant height, stem diameter, canopy diameter, stem basal area and stem volume.

Estimativa da exigência hídrica do amendoim usando um modelo agrometeorológico

In the experimental area of the Department of Environmental Sciences (21.85° S; 48.43° W; 786 m), in the School of Agronomical Sciences, UNESP, Botucatu, SP, an experiment was carried out using peanut (Arachis hypogaea L), cv. IAC-TATU-ST, to quantify the crop daily water requirements. During the peanut crop cycle, the environmental variables, such as rainfall, air temperature, air relative humidity, soil matric potential, soil heat flux and radiation balance, have been registered continually. These measurements were used to calculate the daily crop evapotranspiration, by the Bowen ratio method. The water replacement required by the peanut crop was done the dripping irrigation system, oriented by a dynamic agrometeorological model that computes the entrance and exit of water in the soil. During the peanut crop cycle, 9.0 mm of water was used from sowing to emergence; 67.0 mm of water, in the growth stage; 166.0 mm, in the flowering stage; 124.0 mm in the final stage and 46.0 mm from physiological maturity to harvest. Oot of 412.0 mm of the total consumption, 246.0 mm of water was supplied by irrigation and 166.0 mm by the rain. The grain yield was 3.15 t ha-1 for 15% of humidity, and the water use efficiency was 0.764 kg m-3.

Consumo e custo de energia elétrica na cultura de citros irrigado por gotejamento e microaspersão, com três lâminas de água

The objective of this work was to analyze the consumption, electric energy cost, and economic results of irrigated citrus (Citrus sinensis). The treatments consisted of a dripping irrigation system with one and two lateral distribution lines, a micro sprinkler irrigation system and a treatment without irrigation. For each irrigation system, three water depths were used: 100%, 75% and 50% of Etc (citrus evapotranspiration). The electric energy cost for two tariff groups, Group A and Group B, was studied. For Group A, the expenses with energy were determined for the Conventional Binomial Structure tariff, the Hour-seasonal tariff (green and blue) and the special tariff for nocturnal irrigation. The kWh cost for the tariff systems were obtained from the website of CPFL (São Paulo State Power and Light Company, Brazil). The best relation between the electric energy consumption (kWh.ha -1) and productivity (t.ha -1) occurred in the treatment irrigated with 50% of the Etc. The irrigated treatments increased productivity. The biggest productivity was observed in the irrigation treatments with 50% of the Etc when compared to the ones with 100% of the Etc. The blue and green Hour-seasonal tariff system of Group A (nocturnal irrigation) was the best option. A biggest economic turnover occurred in the treatments irrigated with 50% of the Etc.

Florescimento da lavoura cafeeira sob diferentes manejos de irrigaçâo

The objective of this work was to evaluate the effect of different irrigation managements on flower induction and bloom of coffee trees. The study was carried out at the experimental area of the Engineering Department at Universidade Federal de Lavras, on Acaia Cerrado MG-1474 coffee cultivar, planted 3.0 meters between rows and 0.6 meters between plants and drip irrigated since planting in 1997. The experimental design was randomized blocks with 4 replicates and 5 irrigation treatment: A= non irrigated; B= irrigated throughout the whole year every time the water available was at most 25% of total available water (TAW); C= irrigated during the whole year every time the water available was at most 75% of TAW; D = treatment C during January, February, March, July, October, November and December and treatment B during April, May, June, August and September; E= treatment C during April, May, June, August and September. Each plot was composed of 10 plants and used 2 plants for the evaluation of secondary branches, number of flowers per flowering, number of fruit and fruit set between September and May during the growing seasons of 2006/2007 and 2007/2008. The different irrigation managements did not significantly influence the total number of flowers, number of branches and percentage of flowers that resulted in fruits. Comparing data from two harvests verified the biennial effect in the total number of flowers, percentage of fruit set and branch gain.

Desempenho do abacaxizeiro cultivar Smooth Cayenne submetido a duas frequências e quatro lâminas de irrigação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quality of papaya hybrid grown under different irrigation depths

Irrigation is a practice widely used in fruit production in the Brazilian Northeast region, including in the papaya crop in order to increase their productivity. For the purpose of knowing the productive potential of papaya hybrid irrigated, an experiment was carried out in order to evaluate the performance of a papaya hybrid under different irrigations depths. Four irrigation depths (50, 75, 100 and 125% of ETo) were tested and the reference evapotranspiration was calculated by the Penman-Monteith model. The hybrid papaya used was UENF/Caliman 01, which was planted in single rows, spaced 4 x 2m from each other, and irrigated by dripping. The experimental design in randomized blocks was used with six replications and three plants per plot. The following variables were evaluated: transversal diameter, longitudinal diameter, pulp thickness, external and internal appearances, soluble solids, titratable acidity, pulp pH and soluble solids/titratable acidity relation. The higher transversal and longitudinal diameters of the fruit were obtained applying an irrigation depth of about 108% of evapotranspiration. The UENF/Caliman 01 hybrid can be cultivated in the semiarid region of the State of Paraiba, Brazil, with replacement rate of 100% ETo, without compromising the quality of the fruits.

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

The aim of this study was to compare the use of water and nitrogen on ratoon sugarcane during irrigated and rain-fed conditions, and to assess the production potential of stalks and sugar with different rates of N-fertilizer on the subsurface drip-irrigated management. The experimental design was a randomized block with four replications for each experiment and treatments: (T1) irrigated, 0kg N ha-1; (T2) irrigated, 70kg N ha-1; (T3) irrigated, 140kg N ha-1; (T4) irrigated, 210kg N ha-1; (T5) not irrigated, 0kg N ha-1, and (T6) not irrigated, 140kg N ha-1. Biometric, technological, dry matter and yield variables were analyzed among the treatments. The irrigation system together with the application of N-fertilizer at 140kg ha-1 presented significant differences in dry matter accumulation of shoots, and for the production of stalks and sugar, respectively 94, 105 and 106%, higher when compared to the not irrigated, without N-fertilizer (T5). There was a positive and synergistic effect of irrigation with N-fertilizer on the productivity of stalks and sugar. Ratoon sugarcane irrigated with subsurface dripping had the highest yield (22Mg ha-1 of sugar) with the dosage of 140kg ha-1 N.

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

The aim of this study was to compare the use of water and nitrogen on ratoon sugarcane during irrigated and rain-fed conditions, and to assess the production potential of stalks and sugar with different rates of N-fertilizer on the subsurface drip-irrigated management. The experimental design was a randomized block with four replications for each experiment and treatments: (T1) irrigated, 0kg N ha-1; (T2) irrigated, 70kg N ha-1; (T3) irrigated, 140kg N ha-1; (T4) irrigated, 210kg N ha-1; (T5) not irrigated, 0kg N ha-1, and (T6) not irrigated, 140kg N ha-1. Biometric, technological, dry matter and yield variables were analyzed among the treatments. The irrigation system together with the application of N-fertilizer at 140kg ha-1 presented significant differences in dry matter accumulation of shoots, and for the production of stalks and sugar, respectively 94, 105 and 106%, higher when compared to the not irrigated, without N-fertilizer (T5). There was a positive and synergistic effect of irrigation with N-fertilizer on the productivity of stalks and sugar. Ratoon sugarcane irrigated with subsurface dripping had the highest yield (22Mg ha-1 of sugar) with the dosage of 140kg ha-1 N.

A Microleakage Study Of Gutta-percha/ah Plus And Resilon/real Self-etch Systems After Different Irrigation Protocols.

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin. The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-etch systems. One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+eDTA; NaOCl+H3PO4; NaOCl+eDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+eDTA; CHX+ H3PO4; CHX+eDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal Se were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests. No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by eDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage. A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE.

Effectiveness of different final irrigation protocols in removing debris in flattened root canals

This study evaluated in vitro the capacity of debris removal from the apical third of flattened root canals, using different final irrigation protocols. Thirty human mandibular central incisors with a mesiodistal flattened root were prepared using rotary instrumentation by Endo-Flare 25.12 and Hero 642 30.06, 35.02, 40.02 files, irrigated with 2 mL of 1% NaOCl after each file. The specimens were randomly distributed into 5 groups according to the final irrigation of root canals: Group I: 10 mL of distilled water (control), Group II: 10 mL of 1% NaOCl for 8 min, Group III: 2 mL of 1% NaOCl for 2 min (repeated 4 times), Group IV: 10 mL of 2.5% NaOCl for 8 min, and Group V: 10 mL of 2.5% NaOCl for 2 min (repeated 4 times). The apical thirds of the specimens were subjected to histological processing and 6-μm cross-sections were obtained and stained with hematoxylin-eosin. The specimens were examined under optical microscopy at ×40 magnification and the images were subjected to morphometric analysis using the Scion image-analysis software. The total area of root canal and the area with debris were measured in square millimeters. Analysis of variance showed no statistically significant difference (p>0.05) among the groups GI (2.39 ± 3.59), GII (2.91 ± 2.21), GIII (0.73 ± 1.36), GIV (0.95 ± 0.84) and GV (0.51 ± 0.22). In conclusion, the final irrigation protocols evaluated in this study using the Luer syringe presented similar performance in the removal of debris from the apical third of flattened root canals.

Tabasco pepper production with CO(2) application using drip irrigation

Tabasco pepper production with CO(2) application using drip irrigation. Application of CO(2) through water reduces the soil solution pH, causing variations in nutrient mobility and consequent effects on the absorption. The objective of this study was to analyze the effects of carbon dioxide rates supplied by drip irrigation in the production of Capsicum frutescens L. crop. A randomized block design with four treatments and eight replications was used. The treatments were four rates of CO(2): 0 (T1), 451.95 (T2); 677.93 (T3) and 903.92 (T4) kg ha(-1). The fruits were counted and weighed; the length and the diameter were obtained from an average of 20 fruits per plant, randomly taken, from each treatment in the plot. The quadratic effect (p < 0.01) occurred for CO(2) on the yield and there was quadratic effect (p < 0.05) of the rates on the number of fruits. There were no effects of CO(2) rates on the green matter, dry matter and fruit length and diameter. The T2 treatment provided greater yield and higher number of fruits per plant with an increase of 16 and 26%, respectively in relation to T1 (without CO(2)). CO(2) application favored the increase in the yield because of the greater number of fruits per plant in the Tabasco pepper crop.

Distribution and storage characterization of soil solution for drip irrigation

The increased use of marginal quality water with drip irrigation requires sound fertigation practices that reconcile environmental concerns with viable crop production objectives. We conducted experiments to characterize dynamics and patterns of soil solution within wet bulb formed by drip irrigation. Time-domain reflectometry probes were used to monitor the distribution of potassium nitrate (KNO(3)) and water distribution from drippers discharging at constant flow rates of 2, 4 and 8 L h(-1) in soil-filled containers. Considering results from different profiles, we observed greater solute storage near the dripper decreasing gradually towards the wetting front. About half of the applied KNO(3) solution (48%) was stored in the first layer (0-0.10 m) for all experiments, 29% was stored in the next layer (0.10-0.20 m). Comparing different dripper flow rates, we observed higher solution storage for 4 L h(-1), with 45, 53 and 47% of applied KNO(3) solution accumulating in the first layer (0-0.10 m) for dripper flow rates of 2, 4 and 8 L h(-1), respectively. The results suggest that based on the volume and frequency used in this experiment, it would be advantageous to apply small amounts of solution at more frequent intervals to reduce deep percolation losses of applied water and solutes.

Economic feasibility of cowpea irrigation in Piaui State

The objective of this work was to evaluate the economic feasibility of cowpea irrigation in Piaui State Brazil. Water balances were carried out on a daily basis using the Thornthwaite and Mather (1955) method, for 165 sites, considering twelve sowings dates and available water capacity in the soil of 20, 40 and 60 mm. The net revenues were estimated with a probability of occurrence of 75%, later being spatialized to Piaui State. Cowpea irrigation was shown to economically viable for all sowing dates, irrespective of the available water capacity. Net revenues varied among several regions of the State, in function of the sowing date and available water capacity in the soil. Considering a planning strategy for Piaui State, sowing on February, I was shown to be most favorable, because it enabled higher net revenue values, covering larger areas of the State.

Optimal irrigation depth for bean crops considering water constraints and farmer`s risk aversion level

Nowadays, the rising competition for the use of water and environmental resources with consequent restrictions for farmers should change the paradigm in terms of irrigation concepts, or rather, in order to attain economical efficiency other than to supply water requirement for the crop. Therefore, taking into account the social and economical role of bean activity in Brazil, as well as the risk inherent to crop due to its high sensibility to both deficit and excessive water, the optimization methods regarding to irrigation management have become more interesting and essential. This study intends to present a way to determine the optimal water supply, considering different combinations between desired bean yield and level of risk, bringing as a result a graph with the former associated with the latter, depending on different water depths.