Agriculture group symposium. Visit to the glasshouse crops research institute

Winsor, G. W.; Massey, D. M.; Adams, Philip; Hurd, R. G.; Besford, R. T.; Menhenett, Roger

doi:10.1002/jsfa.2740290712

Cited by 5 publications

(4 citation statements)

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“…A detailed and comprehensive summary of the early studies was published by Homer Chapman in 1963 [30]. Additional summaries have been published by Robinson [31] and Bennett [32]. A thorough discussion of principles and a concise table of optimal nutrient concentrations is provided by Marschner ([33], Table 11.5).…”

Section: Optimal Nutrient Concentration In Leaf Tissuementioning

confidence: 99%

Principles of Nutrient and Water Management for Indoor Agriculture

et al. 2022

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Mass balance principles are a cornerstone of efficient fertilizer use and can be utilized to optimize plant nutrition without discarding or leaching solution. Here, we describe the maintenance of closed hydroponic and soilless substrate systems based on mass balance. Water removed by transpiration is restored with solution that replaces the nutrients that were taken up with the water. The concentration of nutrients in this refill/irrigation solution is determined by multiplying the optimal concentration of each nutrient in plant tissue by the water-use efficiency (WUE; ratio of dry mass to water transpired). Optimal leaf nutrient concentrations are well established, but WUE in controlled environments varies widely and is less well characterized. Elevated CO2 increases photosynthesis and demand for nutrients, but partially closes stomata and reduces transpiration; so high CO2 dramatically increases WUE. The concentration of the refill/irrigation solution must be adjusted to account for a two-fold range of WUE, from 3 g L−1 in ambient CO2 in lower humidity, to 6 g L−1 in elevated CO2 in higher humidity. WUE and nutrient requirements vary during the vegetative and reproductive stages of growth, and adjustment of the solution over the lifecycle can be beneficial. Measurement of solution electrical conductivity (EC) is helpful, but if the solution is appropriate, low EC usually means healthy plants and active nutrient uptake. The ammonium to nitrate ratio is critical to pH management. We have applied these principles across multiple species and environments to achieve long-term, steady-state nutrient concentrations with no discharge or leaching of solution.

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Section: Optimal Nutrient Concentration In Leaf Tissuementioning

confidence: 99%

Principles of Nutrient and Water Management for Indoor Agriculture

et al. 2022

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“…The nutrient film technique was developed during the late 1960s by Dr. Allan Cooper at the Glasshouse Crops Research Institute, Little hampton, England (Winsor et al 1979); a number of subsequent refinements have been developed at the same institution (Graves 1983). Together with the modified systems to which it has given rise (which will be described subsequently), NFT appears to be the most rapidly evolving type of liquid hydroponic system today.…”

Section: A Nutrient Film Technique (Nft)mentioning

confidence: 99%

Hydroponic Vegetable Production

Jensen

Collins

1985

Horticultural Reviews

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“…NFT systems (as described by e.g. Cooper, 1979;Graves, 1983;Hall & Wilson, 1986;Wild et al, 1988;Winsor et al, 1979) are suita ble to study uptake patterns under commercial conditions, since they have the smallest buffering, i.e. changes can be observed rapidly, and mixing is almost com plete.…”

Section: Introductionmentioning

confidence: 99%

Uptake of nutrients by lettuce on NFT with controlled composition of the nutrient solution.

Heinen¹,

Jager²,

Niers³

1991

NJAS

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An automatically-controlled recirculating NFT system was developed, consisting of a growth unit and a measuring and control unit. It is described together with some basic growth and uptake models. Results are presented of a preliminary experiment with the lettuce cultivar Sitonia (using manual control and nutrient dosage). The % DM in the heads decreased from 6.86 (week 1, 20 June 1988) to 3.89 (week 5, 25 July). The shoot:root ratio increased from 0.50 (week 1) to 6.47 (week 6). The time courses of DW increase and cumulative uptake of macronutrients were well described by exponential equations. The cumulative uptake determined from the loss of nutrients from the nutrient solution exceeded that determined from plant analysis. Cumulative uptake as a function of cumulative daily radiation was well described by a logistic equation. Some constant plant uptake ratios between micro- and macronutrients were observed: Cl uptake was related to that of N, K, P or Mg, and B uptake to that of K. DW as a function of transpiration was also well described by a logistic model, with an average DM production of 3.1 g/litre transpired; a logistic model also expressed transpiration as a function of radiation, with an average transpiration output of 5.8 litres/unit (kJ/cmsuperscript 2) increase in radiation. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Agriculture group symposium. Visit to the glasshouse crops research institute

Abstract: Some aspects of the nutrition of tomatoes have been studied in shallow, recirculating, solution culture ('nutrient film culture'). The plants (cv Sonato) were grown in greenhouses under semicommercial conditions. In a factorial experiment with nitrogen (25 % NH4-N+ 75 % Nos-N) at

Cited by 5 publications

References 5 publications

Principles of Nutrient and Water Management for Indoor Agriculture

Principles of Nutrient and Water Management for Indoor Agriculture

Hydroponic Vegetable Production

Uptake of nutrients by lettuce on NFT with controlled composition of the nutrient solution.

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