Automatically controlled deficit irrigation of lettuce in “organic potponics”

Valença, David da Cunha; Carvalho, Daniel Fonseca de; Reinert, Fernanda; Azevedo, Ricardo Antunes; Pinho, Camila Ferreira de; Médici, Leonardo Oliveira

doi:10.1590/1678-992x-2016-0331

Cited by 12 publications

(19 citation statements)

References 29 publications

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“…On leafs important physiological processes occur such as photosynthesis, respiration and transpiration. These processes are dependents of stomatal opening, which is closely correlated with soil moisture (Valença et al, 2018;Mu & Fang, 2017). Undoubtedly, the condition of high soil water depletion is unfavorable to growing of coriander.…”

Section: Discussionmentioning

confidence: 99%

“…Under moderate soil water deficit, maybe the coriander produce more chlorophyll "a" in order to maximize the efficiency of solar radiation absorption or it is possible that occurs the effect of concentration due to the lower growth observed for the leafs (Valença et al, 2018). However, under severe soil water deficit can increase the degradation of chlorophyll "a" (Valença et al, 2018) as observed in arugula (Freitas et al, 2017) and sweet potato (Delazari et al, 2018). Low chlorophyll "a" means decreasing of photosynthesis efficiency and consequently, less biomass accumulation.…”

Section: Discussionmentioning

confidence: 99%

“…The LAI was correlated negatively with LICb (r 2 : -0.84, P: 0.027). Probably, occur the effect of concentration of chlorophyll "b" (Valença et al, 2018). Possibly, the chlorophyll "b" is more resistant to degradation than chlorophyll "a" and can be an important index of hydric stress.…”

Section: Discussionmentioning

confidence: 99%

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Morphological and Ecophysiological Indicators for Coriander Under Irrigation Depths and Nitrogen Levels

Delazari¹,

Copati²,

Silva³

et al. 2019

JAS

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Nitrogen fertilization and supplying of water are crucial factors for quality and quantity produces of coriander. The objective of this study was to evaluate morphological and ecophysiological characteristics for coriander under five irrigation depths and two doses of nitrogen (N). Experimental layout was completely randomized design in a split plot scheme with five replications. The irrigation depths (plot) was 25, 50, 75, 100 and 125% of crop evapotranspiration (ETc). The doses of N (subplot) corresponded to 35 and 70 kg ha-1. The cultivation of coriander (“Vedete”) was in a protected environment. The ratio between the aerial part and roots linearly increased with the increment of the irrigation depths and was highest under 70 kg ha-1 of nitrogen. The leaf area index linearly increased with the increment of the irrigation depths at both doses of N. The leaf index of chlorophyll “a” was highest under irrigation depths of 87 and 75% of ETc for 35 and 70 kg ha-1 of N, respectively. The leaf index of chlorophyll “b” decrease linearly with the increase of irrigation depths in both doses of N. The nitrogen use efficiency was maximized with high soil moisture conditions. The water use efficiency decreases linearly with increasing of irrigation depth. The best irrigation depth and nitrogen dose obtained in this study was 125% of ETc and 70 kg/ha. The leaf index of chlorophyll “a” and “b” are important indicators of hydric stress. The leaf index of chlorophyll “b” are negatively correlated with leaf area index. N supply increase the water use efficiency.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Morphological and Ecophysiological Indicators for Coriander Under Irrigation Depths and Nitrogen Levels

Delazari¹,

Copati²,

Silva³

et al. 2019

JAS

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“…This device has been used in several field studies [ 17 ] and greenhouse studies [ 18 ], using different soils or substrates for plants. It is presented as an alternative in irrigation management [ 19 ] and has the advantage of being built with low cost materials [ 20 ]. Two actuators were used for each plant species studied, independently installed in two tubes with treatment corresponding to the highest flow rate (V4), totaling 6 actuators for the 3 experiments.…”

Section: Methodsmentioning

confidence: 99%

Water requirement and growth indicators of forest tree species seedlings produced with automated irrigation management

et al. 2020

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The lack of information regarding the water requirement of tree species results in water waste in the seedlings production in nurseries. Water requirement, the growth plant factors and water efficiencies for height and diameter were determined for Schizolobium parahyba (Vell.) Blake, Cytharexylum myrianthum Cham. and Ceiba speciosa Ravenna seedlings, under automated irrigation management and greenhouse conditions, located at 22 o 45’53” S and 43 o 41’50” W. We used sewage sludge biosolids as substrate in the seedling phase (280 cm -3 tube), and sandy soil material in the initial pot growth phase (18 dm -3 pot). In the seedlings phase, four water replacement levels were applied to the substrate, by drip irrigation, corresponding to average replacement ranging from 40 (V1) to 100% (V4) of the species water requirement. Seedlings developed properly and 80 days after emergence, S . parahyba , C . myrianthum and C . speciosa seedlings received, respectively, 2.40, 1.08 and 0.85 L per plant, for V4. After growth phase (230 DAE), the total water volumes were, respectively, 70.0, 50.3 and 52.7 L per plant. Under adequate water supply, there were rapid recovery and growth of the species, even for the seedlings which showed different height and diameter in the tube phase. The growth plant factors values found were below 0.5 for all species indicating low sensitivity to growth, both in height and in diameter, in response to water deficit. Water efficiency indicators point to distinct trends between the two phases, and C . speciosa has higher values of water efficiencies for height (80.7 and 17.0 cm L -1 ) and diameter (2.1 and 0.5 mm L -1 ) in both phases.

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“…In a horticultural medium, Newby et al [42] used a Ψm ranging from −20 to −100 hPa as non-stressing conditions for growing flowers. Valença et al [43] indicated that Ψm ranging from −40 to −120 hPa caused water stress for papaya, but not for lettuce. For vegetable crops growing in a loamy sand, Bonachela et al [40] considered −100 to −200 hPa, −200 to −300 hPa and −300 to −500 hPa as high, conventional and low soil water availability, respectively.…”

Section: Water Stress Controlmentioning

confidence: 99%

Can Organic Amendments Improve Soil Physical Characteristics and Increase Maize Performances in Contrasting Soil Water Regimes?

et al. 2021

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Organic amendments are believed to help increase the soil carbon storage and therefore improve soil quality, which may be important in the context of climate change. However, the added value of organic amendments for farmers must be clearly demonstrated in order to convince them of the utility of their use. The aims of this study were: (i) to investigate the impact on maize of compost and vermicompost combined with two levels (negligible and significant) of plant water stress; and (ii) to determine how the organic amendments affected the soil’s physical properties and maize productivity. Water stress levels were imposed by controlling the matric potential of soil columns in which cultivated soil characteristics was mimicked (10 cm topsoil with organic amendments, above a 50 cm subsoil without any inputs containing the majority of the roots). Plant and soil characteristics were monitored daily for 70 days. Our results show that the use of organic amendments is profitable for farmers as: (i) maize performances were increased in both moisture regimes; and (ii) the improvement was particularly striking in terms of yield. No additional benefits were measured when using vermicompost instead of compost. The data suggest that the improvement in plant characteristics did not result from increased water storage in the soils with organic amendments, but rather from better access to the water, resulting in faster root development in the macroporosity of the amended soils.

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Automatically controlled deficit irrigation of lettuce in “organic potponics”

Abstract: Concerns with water crisis involve all sectors of society and irrigated agriculture remains the main water consumer. This study evaluated an agricultural production system for lettuce cultivation in greenhouse, "organic potponics", to economize water and manure use, using

Cited by 12 publications

References 29 publications

Morphological and Ecophysiological Indicators for Coriander Under Irrigation Depths and Nitrogen Levels

Morphological and Ecophysiological Indicators for Coriander Under Irrigation Depths and Nitrogen Levels

Water requirement and growth indicators of forest tree species seedlings produced with automated irrigation management

Can Organic Amendments Improve Soil Physical Characteristics and Increase Maize Performances in Contrasting Soil Water Regimes?

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