Comprehensive Study On Carbon Budget Of Organic Vegetable’s Growth Based On The Internet Of Things Monitoring Technology

Based on the theory of system dynamics(SD) and vensim PLE modeling software, this paper established the organic vegetable growth and carbon balance estimation model taking four kinds of organic vegetables as the research object. Choosing four kinds of organic vegetables: lettuce(leaf vegetables), cucumber(actindia)tomato(solanaceous) and cowpea(beans) as the research object, we obtain the diurnal variation of the various environmental factors by monitoring the real-time environmental factors such as surface temperature and humidity of vegetable field and soil,light intensity, CO2 concentration and so on. Then combined with the related research, we estimate the carbon sequestration ability of vegetable field and verify the model by using the data of field observation and records. The main research results are as follows:(1) In terms of the carbon sink capacity sequestration,tomato(3436.11 kgCO2·hm-2) hold the most,cowpea(3122.83 kgCO2·hm-2) rank second and at last is the lettuce(2897.1 kgCO2·hm-2). Although tomato hold the largest total carbon,soil respiration carbon emissions is also large. From the perspective of the carbon budget for the vegetable farmland ecosystem, cucumber farmland ecosystem occupy the first place for the carbon sink capacity sequestration of(1668.87 kgCO2·hm-2), then comes the cowpea(1647.43 kgCO2·hm-2), followed by tomato(1534.06 kgCO2·hm-2), lettuce hold a minimum of solid carbon(326.97 kgCO2·hm-2).(2) The ability of per day per unit area of carbon fixation of lettuce, cucumber, tomato and cowpea are 9.80 gCO2·m-2·d-1, 23.39 g CO2·m-2·d-1, 18.56 gCO2·m-2·d-1 and 26.86 gCO2·m-2·d-1 respectively. Cowpea has the strongest ability of carbon sequestration while the lettuce has the worst carbon sequestration ability. The carbon sequestration ability of cowpea, cucumbers and tomatoes are higher than alpine grassland(11.52 gCO2·m-2·d-1) and below the oasis C4 plants of maize(38.47 gCO2·m-2·d-1).(3) In order of the leaf area, it goes: lettuce(0.0256 m2), cucumber(0.0169 m2),cowpea(0.0113 m2), tomato(0.0089 m2). All in all, the total leaf area has a certain relationship with the carbon sink capacity. The vegetable with a larger leaf area always has stronger carbon sink capacity.(4) The photosynthetic rate of vegetable is positively correlated with the solid carbon. The cucumber with the strongest photosynthetic rate has the highest carbon sink capacity, followed by the cowpea. And the lettuce has the minimum carbon sink capacity with the weakest photosynthetic rate.(5) The diurnal variation CO2 concentration during the period of observation presents the characteristics of low during the day and high at night because of the vegetable photosynthesis during the day. Comparing with the daily change curve of PAR, the time of CO2 concentration starting to decline is basically the same with PAR. And it picks up after PAR reaching maximum value which takes on a consistent rule with the vegetable photosynthesis. From the point of total CO2 concentration, cucumber field hold the largest total CO2 concentration, followed by the cowpea field with the strongest carbon sequestration capacity, lettuce field has the minimum total CO2 concentration with the weakest carbon sequestration ability.