Distribution of nutrients and water in rockwool slabs

Sasaki

J. Japan. Soc. Hort. Sci.

et al. 2010

We compared the effects of quantitative control in closed system versus electrical conductivity (EC)-based control in open system of nutrients on the growth and yield of tomatoes in rockwool cultivation. Quantitative control supplied all nutrients once a day based on criteria for three application rates (1.0 ×, 1.25 ×, and 1.5 × the standard). These criteria were previously developed in the deep flow technique (DFT) to estimate their nutrient requirements, which used the three-day average amount of water absorbed by tomato plants. We compared the quantitative control in a closed system with two EC treatments in an open system, in which we supplied nutrient solution at high and low EC ranges. The 1.0 × quantity standard reduced the nutrient supply to 30-37% of the levels used in the low-EC treatment. N, P, and K concentrations in the 1.0 × substrate solution remained low and stable for two months after transplanting. The 1.0 × treatment had 27% lower total leaf dry weight and 23% higher total fruit yield than the low-EC treatment. However, greatly reduced growth and nitrogen content of upper leaf and slightly lower soluble solids content in the fruits suggest that the 1.0 × standard might provide insufficient nutrients during late growth stages. Excessive nutrient supplies, which were much lower than the low-EC treatment, increased substrate salinity owing to the accumulation of nutrients during the latter half of the growth period in the 1.25 × and 1.5 × treatments. The stable EC and nutrient concentrations in the 1.0 × substrate solution over time suggest that the three-day adjustment interval would be short enough. The quantity criteria developed for the DFT system could generally be applied to long-term rockwool culture, but the optimum range of nutrient supply was found to be from 1.0 × to 1.25 × the DFT standard in the later growth stages.

Section: Introductionmentioning

confidence: 99%

Growth and Yield of Tomato Plants as Influenced by Nutrient Application Rates with Quantitative Control in Closed Rockwool Cultivation

Sasaki

J. Japan. Soc. Hort. Sci.

et al. 2010

“…The occurrence of soil-limited factors (expensive chemical soil disinfection methods, low yields and possible plant residues, water shortage and increase in salinity of natural soils) has increased demand for a suitable technology adapted to soilless culture (De Rijck and Schrevens 1998) and exploitation of local materials for use as growing media with specific physicochemical properties (Ortega et al 1996). Inorganic substrates such as perlite, sand and pumice, are chemically inert, making it possible to supply nutrients in a controlled manner (De Rijck and Schrevens 1998). Several studies reported the favorable effect that organic materials have on plant growth (Sawan and Eissa 1996, Tehranifar et al 2007, Tzortzakis and Economakis 2008, as increased substrate porosity and water holding capacity (Hardgrave and Harriman 1995).…”

mentioning

confidence: 99%

Use of sawdust, coco soil and pumice in hydroponically grown strawberry

Marinou¹,

Chrysargyris²,

Tzortzakis³

2013

Plant Soil Environ.

Strawberry (Fragaria × ananassa Duch.) plants were grown hydroponically in different ratio of sawdust (Saw-100), coco soil (Coc-100) and/or pumice (Pum-100) mixtures. Leaf number doubled in plants grown in Saw-100 while runners (stolons) number increased up to 70% in plants grown in Coc-100 compared with the control treatment (Pum-100). Fruit number increased (up to 50%) in plants grown in Pum-100. Leaf stomatal conductance, photosynthetic rate and internal concentration of CO 2 differentiated according to the plant vegetative or reproductive stage and/or substrate medium. Leaf and stem fresh weight as well as leaf area was increased (up to 32, 24 and 44%, respectively) in case of Coc-100 compared with the Saw-100 or Pum-100. Plant yield was doubled when Pum-Saw (50-50) was used compared with the Saw-100, which is due to the reduced fruit number produced rather than the difference in fruit fresh weight. Substrate affected fruit quality parameters. The present findings highlight the putative use of organic medium i.e. Sawdust on top of the widely used coco soil as substrate medium in strawberry culture.

“…Leachate EC was the highest after each flushing event in RWF (data not shown), although the average leachate EC during the experiment was the same for RWL and RWF (Table 1). This can be explained by the tendency of water in drip irrigation to flow downwards rather than to spread horizontally (De Rijck & Schrevens, 1998). In this way, salt accumulated around the wet bulb produced by the dripper and the flushing washed out some of these salts.…”

Section: Resultsmentioning

confidence: 99%

Saline reclaimed wastewater can be used to produce potted weeping fig (Ficus benjamina L.) with minimal effects on plant quality

Valdés¹,

Miralles²,

Ochoa³

et al. 2012

Span. j. agric. res.

The objective of the present study was to investigate the limitations of irrigation with saline reclaimed wastewater (RW) for producing potted weeping fig (Ficus benjamina L.). Furthermore, two different levels of leaching were studied to ascertain whether either reduces the negative effects of RW. Three irrigation treatments were applied: a) well water (control), b) RW (5 dS m -1 ) with a constant leaching fraction of 23% (RWL), and c) RW (5 dS m -1 ) with a constant leaching fraction of 15% and 50% flushing every nine irrigation events (RWF). After five months of exposure to the RW, plant size, leaf area, specific leaf area, plant DW, stem diameter and shoot/root ratio were reduced, but both compactness and the appearance of the plants remained high. RWF reduced leaf area, plant dry weight, stem diameter, leaf lightness, leaf chroma and leaf SPAD compared with the RWL. Water consumption per pot was higher in control (50.58 L), followed by RWL (24.29 L) and RWF (19.6 L). Photosynthesis and stomatal conductance were 50% lower in RWL plants than in the control, while the RWF plants had the lowest rates. RWF caused damages in the photochemical apparatus. This study confirms that: a) weeping fig is a good candidate for being grown with saline RW without compromising its aesthetic value; b) RW may be regarded as a good alternative to the retardants used in this plant; and c) the recommended irrigation would be RWL.Additional key words: irrigation; ornamental plant; pot plant; salinity. Resumen El riego con agua residual depurada salina permite producir ficus (Ficus benjamina L.) en maceta con una pérdida de calidad mínimaEl objetivo del estudio fue investigar las limitaciones del riego con agua residual regenerada salina (RW) en la producción de Ficus benjamina L. en maceta. Se valoró también la efectividad de dos niveles de drenaje para reducir los efectos negativos del RW. Los tratamientos fueron: a) agua no salina (control), b) RW con 5 dS m -1 y un 23% de drenaje (RWL), y c) RW con 5 dS m -1 y un 15% de drenaje, más un 50% de lavado cada 9 riegos (RWF). Después de 5 meses bajo RW el tamaño de la planta, área foliar, área foliar específica, peso seco de la planta, diámetro del tallo y el ratio parte aérea/raíz fueron reducidos, mientras que la compacidad y el aspecto ornamental estuvieron dentro de los patrones comerciales adecuados. RWF produjo una disminución del área foliar, peso seco de la planta, diámetro del tallo, luminosidad y saturación del color de la hoja, y de la clorofila foliar (SPAD) en comparación con RWL. El consumo de agua fue mayor en el control (50,58 L), seguido de RWL (24,29 L) y RWF (19,6 L). La fotosíntesis y la conductancia estomática fueron un 50% menor en las plantas bajo RWL respecto al control, mientras que las plantas bajo RWF presentaron los registros más bajos. RWF produjo daños en el aparato fotoquímico. Este estudio indica que: a)