| Chinese solar greenhouse plays an important role in the production of vegetable in China.The resources and environmental problems of soil cultivation,including soil continuous cropping obstacles,water and fertilizer resources waste and groundwater pollution,restrict its sustainable development in Chinese solar greenhouse.In addition,the problem of high and low temperature in the process of Chinese solar greenhouse production is an important factor that restricts the production of Chinese solar greenhouse.Therefore,it is great practical significance to solve the problems of resources and environment and the high and low temperature stress in the production of Chinese solar greenhouse.This study constructed a new method called soil-ridged substrate-embedded cultivation method in Chinese solar greenhouse.This study researched the temperature change,mechanism and the effect in high and low temperature environment.The water and fertilizer management system of sweet pepper cultivated on SSC was preliminarily determined.In addition,the application and effect of heating and lighting on SSC in the low temperature environment in winter was studied,and the performance of cooling in high temperature environment in summer also was studied.SSC method makes full use advanges of soilless culture with high yield and high efficiency and soil culture with root zone temperature stability characteristics.SSC method which combined with the integration of water and fertilizer technology,improve the crop root zone environment?temperature,water and fertilizer etc.?,and promote crop growth and yield.1.Changes of root zone temperature,pepper growth and yield index of the SR?soil ridge cultivation?,SSC-P?polyethylene groove embedded in ridge?and SSC-W?wire mesh plus plastic film made embedded in ridge?and PG?polyethylene groove?were studied by the method of field experiment.The utilization and profit and loss of the formulated nutrient solution were monitored.During 16 to 20March,PG,SSC-P and SSC-W improved average minimum root zone temperature by 1.01,0.75 and1.16?compared with SR,respectively.During 1 to 5 June,SSC-P and SSC-W decreased average maximum root zone temperature 1.28 and 1.29?compared with SR,respectively,while PG was 1.44?higher than that of SR.Temperature difference of daytime and nighttime of SSC-W was the lowest,while the temperature difference between the highest and the lowest temperature of SSC-W also was the lowest during two periods.SSC patterns improved remarkably the buffer capacity of root zone temperature,and the buffer capacity of SSC-W was slightly better than SSC-P.SSC-P and SSC-W improved plant height,stem diameter,leaf chlorophyll contents of sweet pepper compared with SR,and SSC-W performed best.SSC-W significantly improved the single fruit weight,fruit size and single plant yield compared with other treatments.Similarly,fruit yield per square meter of sweet pepper cultivated on SSC-P and SSC-W improved by 21.24%and 50.33%than that of SR(3.06 kg·m-2),while PG lowered the yield by 13.72%compared with SR.The amount of nutrient solution in the three periods is basically reasonable,but there are still some surplus in the cultivation tank,which can further reduce the amount of water and fertilizer,so as to achieve more efficient purposes.2.Effects of SSC ridge with different width,embedded depth and lateral soil forms on root zone temperature and heat on sweet pepper growth and fruit yield index were studied by the method of field experiment.The results showed that T6 was higher 0.55,1.27 and 1.33?than that of T1,T2 and T5,respectively,with different width.For ridges with different embedded depth and lateral soil forms,T6was higher 0.44,0.84 and 1.55?than T3,T4 and T5,respectively.The temperature change was related to the intensity of heat flux transfer,and the heat transfer in the lateral and vertical direction of T6 is relatively slow,and the temperature is the highest.In addition,sweet pepper growth of T2,T5,T6 were better than that of T1 with different width,and T6 was the best.For ridges with different embedded depth and lateral soil forms,sweet pepper growth of T5 was worse than that of other treatments,and T3and T6 were not significantly different,but T6 was better than that of T3.In short,the low temperature resistant ability of T6 was stronger than other treatments,and it can promote the growth of pepper seedling.Sweet pepper fruit yield of T6(3.69 kg·m-2)was the highest,and the fruit yield was decreased with the decrease of the height and width of ridges.And monitoring found that the adjusted nutrient solution system can meet the growth needs of SSC sweet pepper with less residue,high utilization of nutrients and more efficient3.Effects of LED supplemental lighting and root zone heating on root zone temperature heat changes,growth and fruit yield of SSC sweet pepper were studied by the method of field experiment in Chinese solar greenhouse.The results showed that SSC had higher root zone temperature compared with CK?without heating and lighting treatment?.Compared different root zone heating treatments,T18maintained a high temperature all day long.The change of heat flux in the root zone and the root zone temperature changes were corresponding,and the change of heat flux in the root zone of T15 and T18treatment were more severe than CK.Both T15 and T18 significantly increased the growth of sweet pepper,and the effect of T18 was more obvious than T15.T18 increased the ground and underground fresh and dry weight significantly.The effect of T18+L treatment on biomass was significantly better than that of T15+L treatment.Yield of T15+L and T18+L were 32.86%and 15.50%higher than that of T15 and T18,respectively,and they were higher 51.29%and 53.87%than that of L.4.Effects of different kinds of plastic films cultivated on SSC on root zone temperature and heat flux and the growth of tomato were studied by the method of field experiment in Chinese solar greenhouse in summer.The results showed that method could decrease under film temperature and root zone temperature compared with CK before planting.Temperatures under film and in root zone of QF were the lowest.Average maximum temperatures under film and in root zone of QF were 12.78 and9.73?cooler than CK,and the average daytime temperatures under film and in the root zone of QF were 7.88 and 6.16?cooler than CK.After planting,average maximum temperatures under film and in root zone of QF were 8.96 and 8.97?cooler than CK,and average daytime temperatures under film and in root zone of QF were 6.02 and 5.47?cooler than CK.But the cooling effect of QF was worse than the previous period caused by high environmental temperature.On the root zone cooling effect,cooling capacity followed by QF>PF>HM>TM>CK.The root zone heat transfer and root zone temperature of QF were the slowest in all treatments.Plant height and stem diameter of tomatoes cultivated on PF and QF were both higher than that of CK.The biomass of tomato seedlings was gradually increased with effect of heat insulation and cooling increasing,and the fresh and dry shoot and root weight of QF was the best,and the growth of tomato seedlings was the best. |
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