In plant light problem, what is one of the most serious problems of spectrum?How many PPFD?
If you do not provide the planting varieties and environmental conditions, it is unable to accurately answer this question, plants are optical radiation can conversion process, optical radiation can follow the law of conservation of energy in the transformation process, for a variety of plants, must first determine the plants need the optical radiation energy every day, otherwise, a series of parameters calculation, there is no basis.
What is a DLI?
DLI (Daily light integral) solar product component
Refers to a day in sunlight available radiation (PAR) per square meter of optical radiation to the product components, unit: mol/m2d.
DLI in agriculture is an important amount of photosynthetic parameters, is the main parameters of agricultural scientific research, has universal guiding significance of planting, in the sun, the sun of photosynthetic irradiance (converted to PPFD) with the weather changing over time, this change will even from below the compensation point and higher than its saturation point, therefore, DLI need according to the method of integral calculation, just can be calculated by multiplying the average PPFD and effective at the beginning of time (hours) to calculate.
In the sun according to the average method to calculate the calculation formula of DLI:
DLI = 0.0036 * PPFD (on average) * valid time.Effective time: hours.
PPFD measured values and the effective time need to adjust according to the compensation point and saturation point.So DLI value fluctuation is bigger, every day need data regression method to determine.
What is the DLA?
DLA (Daily light amount) sunlight is reasonable
Refers to the artificial light every day of every square metre under photoperiodic PPFD generated by the molar number of photons, unit: mol/m2d.
Disclaimer: institute of DLA parameters by the nice bright light solid Xu Dong definition, reference to indicate the source.
As a result of plant lamp light under the light cycle is constant, the calculation formula of DLA:
DLA PPFD = 0.0036 * * PP.PP - light cycle (h)
DLA is calculated on the basis of plant varieties and planting environment comprehensive, different plants of DLA.
DLA is plant factories and planting technology, the main parameters of greenhouse fill light is the main basis of plant lamp design, DLA through experimental data or by DLI after weighted preliminary concluded that need correction on the experimental data, below are two plant varieties of DLA value for reference:
Lettuce DLA: September 11.
Tomato DLA: 16-20.
The difference between the DLA and DLI
Calculation formula of DLA with DLI close, unit is the same, but the ways of the selection of different amount of calculation.
DLA is set for plant varieties, DLI is solar radiation in the area.
DLA is to determine the value of the, DLI has randomness, DLI lasts only average said.
DLI only can be used in field and greenhouse greenhouses, cannot be used in indoor, DLA with plant attributes, can be applied in the field, greenhouse, indoor plants.
DLA is planting process, the main parameters used in quantitative analysis, DLI auxiliary parameter, is used for qualitative analysis.
Optical radiation parameters of plant factories if there is no basis for DLA, produces the result of the uncertainty.
DLA ray radiation energy consumption determines the artificial environment, this parameter can be calculated by planting cost.
In greenhouses, outdoor and indoor DLI less than DLI, greenhouse DLI is usually less than the DLA of many plant species, when indoor DLI is less than the DLA, you need to fill light, the light is a DLA - DLI, when indoor DLI is greater than the DLA, need not fill light.
DLA parameters established scientific greenhouse whether fill light and provides theoretical basis to fill light amount of.System DLA artificial environment to establish database, system can provide the basis of plant factory application data, has very important significance.
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Plants lamp enterprises can participate in the light spectrum technology BBS, to participate in the plant light spectrum technology project communication.