Determining injection strategies of phosphorus‐coupled nitrogen fertigation based on clogging control of drip emitters with saline water application *

2021 ◽  
Author(s):  
Zhen Wang ◽  
Jiusheng Li ◽  
Xiaoqi Yang
Author(s):  
Francisco I. F. Oliveira ◽  
Wiliana J. F. de Medeiros ◽  
Claudivan F. de Lacerda ◽  
Antônia L. R. Neves ◽  
Davi R. Oliveira

ABSTRACT Biosaline agriculture is an option for using waters with lower quality. Thus, the objective of this study was to evaluate the growth of ornamental species under irrigation with increasing water salinity levels in two methods of water application. The study was conducted in a greenhouse, in the municipality of Fortaleza, Ceará, Brazil. The treatments were distributed in randomized blocks in split plots, with six levels of water salinity in the plots (0.6 - control, 1.2, 1.8, 2.4, 3.0 and 3.6 dS m-1), two methods of water application in the subplots (localized and sprinkler irrigation) and four ornamental species in the sub-subplots (Catharanthus roseus, Allamanda cathartica, Ixora coccinea and Duranta erecta), with four replicates. Increase in irrigation water electrical conductivity reduced the growth of the studied ornamental species. It was not possible to establish an ideal method for irrigation of ornamental species. Effects of non-localized irrigation on leaf growth were more evident in the species C. roseus and D. erecta, which showed higher specific leaf area.


2021 ◽  
Vol 9 (04) ◽  
pp. 68-113
Author(s):  
D. Kausalya M.Sc Nursing ◽  

Objectives:To assess the level of painresponse during heel prick among newborn.To evaluatetheeffectivenessofwarmsalinewaterapplicationonpainresponseduringheelprickamongnewborn.Toassociatethepainresponseduringheelprickamongnewborn at NICU, Government Rajaji Hospital, Madurai with their baseline variables. Hypotheses: There isa statistically significant difference betweenthe post test levelof pain response during heel prick among newborn both in intervention and controlgroup.Thereisastatisticallysignificantassociationbetweenthelevelofpainresponse during heel prick among newborn at NICU with their baseline variables.Conceptual framework: Roys adaptation model. Methodology: True experimentalresearchdesignwasused,60samplesselectedby Simplerandomsamplingandintervention given 2 minutes before heel prick. Post test was assessed by NeonatalInfantPainScale.Results:Thestudyrevealedthattherewasasignificantreductionin level of pain response during heel prick (t=1.25, p=0.21) at 0.05 level. Conclusion:Statistical evidence shows that warm saline during heel prick was effective.


2000 ◽  
Vol 40 (5) ◽  
pp. 739 ◽  
Author(s):  
R. J. Elder ◽  
W. N. B. Macleod ◽  
K. L. Bell ◽  
J. A. Tyas ◽  
R. L. Gillespie

Highly variable, outcrossed papaya lines irrigated with overhead sprinklers were grown at Yarwun (151.3˚E, 23.75˚S) in Queensland, Australia. The inherent variability made scientifically based comparative studies impractical. The advent of uniform hybrid papaya lines allowed the testing of 2 of these hybrids under 3 irrigation methods, 2 of which had the potential to greatly reduce water use compared with overhead sprinklers. Yields of 92 t/ha.year were achieved by both papaya Hybrids 29 and 1E. Water application method did not influence yield. About 26% of plants were lost due to the phytoplasma diseases dieback, yellow crinkle and mosaic over the life of the trial. Downward yield fluctuations were related to poor fruit set in winter when pollinators (Family Sphingidae) were not present and growth was slow due to hot dry periods affecting fruit set. The resultant fruit (about 6 months later) were small and reduced in number. Irrigation with overhead sprinklers using saline water (1400–4000 S/cm) damaged leaves and reduced growth of plants. Winter spot was most severe in July, August and September, in Hybrid 29 with overhead irrigation. Height of plants 13 weeks after planting was greater under trickle irrigation due to less damage from the saline water supply than in the overhead sprinkler treatment. Hybrid 29 set fruit at 94.3 cm above ground compared with 117.6 cm for Hybrid 1E.


1990 ◽  
Vol 33 (5) ◽  
pp. 1563 ◽  
Author(s):  
R. G. Evans ◽  
C. J. Smith ◽  
J. D. Oster ◽  
B. A. Myers

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 321 ◽  
Author(s):  
Donald L. Suarez ◽  
Nydia Celis ◽  
Ray G. Anderson ◽  
Devinder Sandhu

Diminishing availability of non-saline water in arid and semiarid regions is of concern to all irrigated agricultural producers, including wine and grape producers. Grapes are not a salt tolerant crop and producers often face the choice of either limiting fresh water application, using alternative saline waters or a combination of both. We examined the salt tolerance and effect of restricted water application on three purported salt tolerant rootstocks grafted to Cabernet Sauvignon scion in a 4-year replicated field experiment. ANOVA indicated significant effects of salinity water stress and rootstock on fruit yields. The 140 Ruggeri scion was the top producer across all treatments including control, followed by Salt Creek, with St. George significantly less productive than 140 Ruggeri across all treatments. In terms of salt tolerance, Salt Creek and 140 Ruggeri were not statistically different but St. George was significantly less tolerant than Salt Creek. In terms of drought tolerance (relative yield), there were no statistical differences among rootstocks. Soil salinity profiles and soil moisture sensors indicated reduced water consumption under high salinity, thus no matric stress under 60% of optimal water application when high salt stress was present. The multiplicative stress model where salt and water stress are individually evaluated did not satisfactorily predict yield under combined salinity and reduced water application, likely due to decreased water consumption under saline conditions. Short term (one year) experiments underestimate salt damage to grape vines as salt tolerance decreased over the 4-year experiment.


2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Khaled Ahmad Aali ◽  
Abdoulmajid Liaghat ◽  
Hossein Dehghanisanij

Author(s):  
Roberto González-De Zayas ◽  
Liosban Lantigua Ponce de León ◽  
Liezel Guerra Rodríguez ◽  
Felipe Matos Pupo ◽  
Leslie Hernández-Fernández

The Cenote Jennifer is an important and unique aquatic sinkhole in Cayo Coco (Jardines del Rey Tourist Destination) that has brackish to saline water. Two samplings were made in 1998 and 2009, and 4 metabolism community experiments in 2009. Some limnological parameters were measured in both samplings (temperature, salinity, pH, dissolved oxygen major ions, hydrogen sulfide, nutrients and others). Community metabolism was measured through incubated oxygen concentration in clear and dark oxygen bottles. Results showed that the sinkhole limnology depends on rainfall and light incidence year, with some stratification episodes, due to halocline or oxycline presence, rather than thermocline. The sinkhole water was oligotrophic (total nitrogen of 41.5 ± 22.2 μmol l−1 and total phosphorus of 0.3 ± 0.2 μmol l−1) and with low productivity (gross primary productivity of 63.0 mg C m−2 d−1). Anoxia and hypoxia were present at the bottom with higher levels of hydrogen sulfide, lower pH and restricted influence of the adjacent sea (2 km away). To protect the Cenote Jennifer, tourist exploitation should be avoided and more resources to ecological and morphological studies should be allocated, and eventually use this aquatic system only for specialized diving. For conservation purposes, illegal garbage disposal in the surrounding forest should end.


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