Microsprinkler Irrigation System Research Articles

Fertirrigação com diferentes doses de NPK e seus efeitos sobre a produção e qualidade de frutos de laranja (Citrus sinensis O.) 'Valência'

O experimento foi realizado na Fazenda Três Irmãos, no município de Pratânia, Estado de São Paulo, com o objetivo de estudar o efeito da fertirrigação com diferentes doses de NPK aplicadas por meio de um sistema de irrigação por microaspersão na cultura da laranja em comparação com a adubação convencional irrigada e não irrigada. A avaliação dos efeitos da irrigação e da fertirrigação na cultura foi feita com base na produção e qualidade dos frutos colhidos, na análise de solo da camada de 0-20 cm e na análise de folhas. Os tratamentos não influenciaram significativamente a produtividade de acordo com a análise estatística realizada, embora se tenha observado uma tendência de maior produtividade nos tratamentos de fertirrigação para uma mesma dose. A análise de qualidade dos frutos não mostrou diferenças significativas entre os tratamentos. Os teores de alguns dos elementos obtidos na análise de solo apresentaram diferenças significativas proporcionadas pela irrigação e/ou modo de aplicação dos fertilizantes à cultura. A análise de folhas diferiu quanto aos teores de Ca, Mg e K.

Using microsprinkler irrigation to reduce leaching in a shrink/swell clay soil

Preferential flow allows agricultural chemicals to rapidly move past crop root zone to subsoil, potentially contaminating groundwater. Deep shrinkage cracks in a shrink/swell soil may serve as preferential flow channels. Design and operation of an irrigation system is critical in shrink/swell soils in order to reduce or eliminate preferential flow while providing sufficient water for plant growth. The objective of this study was to compare microsprinkler irrigation (MI) and surface flood irrigation (FI) systems for their ability to reduce preferential flow and chemical leaching through a shrink/swell soil in a pear orchard. The MI system applied water at a rate of 2.8 mm h −1, and the FI followed the traditional orchard irrigation method. Bromide tracer was applied to the pear orchard. Soil cores and percolate samples from passive capillary samplers (PCAPS) installed at 1.2 m depth were collected to test for the presence of Br tracer in the soil and percolate. The MI system greatly decreased water and Br leaching from soil to the PCAPS in comparison to FI. The percolate in MI was nearly zero. Most of the loss of Br occurred in the first one or two FI events. MI systems, such as that used in this study should be considered as an alternative to FI in such shrink/swell soils to reduce macropore flow.

Uniformidade de sistemas de irrigação localizada: validação de equações

O coeficiente de uniformidade nos sistemas de irrigação localizada é importante por permitir a avaliação de sistemas ou somente projetados. Quanto aos diferentes métodos aplicáveis, é importante que se defina a correlação entre os mesmos, de forma a permitir a comparação entre os equipamentos. Para avaliação da eficácia de equações de correlação entre os coeficientes de uniformidade de emissão, uniformidade de emissão absoluta e uniformidade estatística, foram comparados os resultados de sua aplicação com valores obtidos pelo uso convencional de cada um desses métodos. A avaliação foi feita a partir de dados obtidos pela aplicação dos três métodos em dois diferentes sistemas de irrigação por microaspersão implantados, tendo sido usado como referência para a avaliação os respectivos coeficientes de uniformidade calculados com base no censo das vazões dos emissores instalados. As baixas diferenças porcentuais entre os valores estimados pelas equações propostas e os obtidos pela aplicação convencional de cada método confirmam a sua validade, permitindo a estimativa da uniformidade de um dos métodos analisados a partir do valor obtido por outro dos métodos estudados.

Yield and Root Growth Responses of Papaya to Partial Root Volume Irrigation by Drip or Microsprinkler Irrigation Systems

`Tainung 2' papaya seedlings were transplanted on 30 Jan. 1996 and irrigated with one, two, or three drip irrigation lines per row in one study and with 90°, 180°, or 360° microsprinkler spray patterns in a second study to determine the reproductive and vegetative growth responses to irrigation design. Variable irrigation duration was used to supply a homogeneous amount of water to each plant in the drip irrigation study. The trench profile method was used in the drip irrigation study, and a monolith method was used in the microsprinkler study to determine root distribution at the end of the dry season (30 May to 2 June). All fruits were harvested and weighed on 26 Aug. Roots proliferated underneath the drip lines during the dry season, and root concentration on the profile walls was inversely related to the number of drip lines. Root concentration underneath one drip line was 3.7 times greater, underneath two drip lines was 2.3 times greater, and underneath three drip lines was 1.9 times greater than root concentration in the non-irrigated zones. Roots also proliferated in the wetted zones of the microsprinkler spray patterns. Mean fruit weight and total harvested fruit weight did not differ among the irrigation treatments within each study. The results indicate that papaya roots are highly morphoplastic and proliferate in wetted zones under partial root volume irrigation. One drip line per row supplied ample irrigation coverage under the conditions of this study.

Insect (Neuroptera: Lepidoptera) Clogging of a Microsprinkler Irrigation System in Florida Citrus

The use of subcanopy irrigation, including microsprinkler systems, has been steadily increasing over the past 15 years by the Florida citrus industry (Smajstrla et al. 1992). Reduced water volume, more efficient delivery of irrigation water to the tree roots, limited water application to competitive weeds all provide the grower with incentives to use these systems (Parsons 1989, Zekri & Parsons 1988, 1989). This technology is especially important to growers because of freeze protection. Various insect and mammal problems have been identified in recent years in association with irrigation systems in Florida. Fire ant colonies, mainly Solenopsis invicta Buren (Hymenoptera: Formicidae), have been observed by the first author to utilize the solar heating potential of the black polyethylene tubing to maintain their eggs and developing young. The eggs and immature ants are found along the underside of feeder lines that run parallel to tree rows in Florida citrus groves. Fire ant species in Florida have caused occasional localized problems by clogging tubing and individual emitters (L. R. Parsons, University of Florida, IFAS, Citrus Research and Education Center, personal communication). Secondary nests of the Argentine ant, Iridomyrmex humilis Mayr, have been found in sprinkler heads in California citrus groves (Haney 1984). Mature larva of Selenisa sueroides (Guenee) (Lepidoptera: Noctuidae) have damaged microsprinkler irrigation systems in several citrus groves in central and southwest Florida since 1987 (Brushwein et al. 1989). The mature larvae leave their host plants (i.e., Aeschynomene spp., Sesbania spp. and Macroptilium lathyroides (L.)) prior to pupation in October and November, climb nearby irrigation sprinklers and chew holes in the flexible pvc tubing. The larvae then enter the tubing and pupate. The level of damage caused by Selenisa sueroides was shown to be related to the abundance and distribution of certain legume host plants, larval population levels, sprinkler type and grove cultural practices (Brushwein et al. 1989). Damage to sprinklers and connecting tubing averaged $797 per site in 1987 (Brushwein et al. 1989). Four species of rodents including the house mouse, Mus musculus L., the cotton mouse, Peromyscus gossypinus palmarius Bangs, the rice rat, Oryzomys palustris natator Chapman and the hispid cotton rat, Sigmodon hispidusfiordanus A. H. Howell were associated with damaged sections of irrigation tubing in tomato fields in southwest Florida (Stansly & Pitts 1990). The rodents had chewed on irrigation tubing resulting in leaks. Of 45 leaks observed in the field, eight were found to be caused by mice and 37 by the two rat species. Most of the damage occurred on 4 mil tubing compared with damage on the 15 mil irrigation tubing. A 52.6-ha citrus grove was planted southeast of Arcadia in DeSoto County during the first 3 weeks in July, 1991. The trees were set at 3.05 x 7.62 m (= 430.5 trees per ha). The citrus varieties included 'Hamlin' orange on Bittersweet rootstocks and 'Rohde Red Valencia' orange on Swingle rootstocks. Japanese millet, Setaria italica (L.) Beauvois, was planted throughout the citrus grove about 1 June 1991.

Over-tree Microsprinkler Irrigation for Spring Freeze Protection of Peaches

“The feasibility of using an over-tree microsprinkler irrigation system for spring freeze protection of `Loring' peach trees [Prunus persica (L.) Batsch] was evaluated under a range of meteorological conditions during Winter 1988-89. Microsprinklers were attached to the underside of polyethylene laterals 2.5 m above ground level and centered over the tree rows. Irrigation rates of 0, 27, 36, and 44 liters/hour per tree were tested on trees trained to an open-center habit using microsprinklers that produced a circular wetting pattern. Microsprinkler irrigation maintained average bud temperature above -2C and 2 to 5C above those of nonirrigated trees under calm conditions, but provided no protection under windy conditions. Flower bud temperatures of irrigated trees were similar for 36 and 44 liters·hour-1, but were slightly lower for 27 liters·hour-1 under conditions typical of spring freezes. Limb breakage due to ice loading was negligible for all application rates, even under advective freeze conditions. Calculated water and energy consumption were reduced by at least 50% and 88%, respectively, by the microsprinkler system, compared to a typical overhead sprinkler system.

Selenisa sueroides (Lepidoptera: Noctuidae): A Pest of Subcanopy Irrigatrion Systems in Citrus in Southwest Florida

Mature larvae of Selenisa sueroides (Guenee) damaged micro-sprinkler irrigation systems in three citrus groves located in Hendry Co., Florida during October and November 1987. After completing development on fabaceous food plants, American jointvetch, Aeschynomene americana L., or phasey bean Macroptilium lathyroides (L.) Urban, larvae left the host plants, climbed nearby irrigation sprinklers, and chewed holes in the flexible polyvinylchloride tubing. Larvae then entered the tubing and pupated. Damage to sprinklers and connecting tubing resulted in additional grove costs that averaged $797 per site (range, 50 to $1,500). The level of damage within each grove was related to the abundance and distribution of host-plants, larval population levels, sprinkler type, and grove cultural practices.

Management of Microsprinkler Systems for Florida Citrus

Irrigation is an essential part of the Florida citrus production system. In one study, irrigation increased yield by 39 to 64% over the non-irrigated controls. Microsprinkler irrigation systems have become the standard for Florida citrus. Microsprinkler and drip systems have been collectively referred to as trickle, low volume irrigation, or microirrigation systems. Compared to overhead sprinklers, low volume systems can save water if they are properly managed. Because these systems usually operate at lower pressures than conventional overhead systems, there can also be appreciable savings from reduced energy costs. In addition, microsprinkler irrigation can provide partial frost protection for both young and mature trees. This document is HS-958, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Date printed: October 2004. 
 HS958/HS204: Management of Microsprinkler Systems for Florida Citrus (ufl.edu)