日光温室甜椒起垄内嵌式基质栽培根区温度日变化特征

针对我国北方地区日光温室冬春季低温胁迫、土壤连作障碍、单产低和水肥资源利用率低等问题,本文设计了一种新型的栽培方法——起垄内嵌式基质栽培方法(soil ridge substrate-embedded cultivation,SRSC),并在早春季节,研究了两种模式的SRSC嵌槽式垄(SRSC-P)和嵌膜(铁丝网槽支撑)式垄(SRSC-W)]及土垄(SR)和单一基质槽垄(NPG)栽培下的甜椒幼苗根区温度的日变化特征。结果表明,日光温室内栽培垄根区温度与温室内、外的气温变化呈显著正相关,室内和栽培垄根区的平均温度分别比室外提高8.07℃和10.93℃,夜间分别提升9.90℃和14.81℃。在夜间低温阶段,SRSC-W维持根区较高温度的能力相对优于SR和SRSC-P,其根区平均温度分别比SR和SRSC-P高1.34℃和0.52℃;在白天高温阶段,SR、SRSC-P、NPG、SRSC-W最高温度平均值分别为28.06℃、27.21℃、29.93℃、26.05℃,SRSC-W抗高温效果最佳,NPG抗高温效果最差。阴天条件下,栽培垄的蓄热保温性能比晴天条件下差。SR白天和夜间的中心根区平均温度皆高于外侧,但SRSC-P和SRSC-W白天外侧温度高,夜间中心根区温度高。栽培垄北部根区温度高于南部根区温度,具有空间差异性,其中SRSC-W栽培模式的南部中心根区温度和北部中心根区温度差异相对于其他处理最小。此外,SRSC-W中心根区温度变化滞后时间最长,温度缓冲能力强。总之,SRSC-W栽培方法维持早春季节夜间甜椒根区温度能力和对低温及高温胁迫的缓冲性最强,且成本低,在日光温室抗低温生产中具有较好的应用前景。

Diurnal change in root zone temperature of soil ridge substrate-embedded cultivation method for sweet pepper in solar greenhouse

In order to deal with the production problems associated with low temperature stress in winter and early spring, continuous cropping obstacles, low yields and low utilization efficiencies of water and fertilizer in solar greenhouses in North China, a novel cultivation method named‘soil ridge substrate-embedded cultivation’ (SRSC) was designed and its performance was investigated. An investigation on root zone temperature of sweet pepper seedlings in two types of SRSC patterns SRSC-P (polyethylene groove embedded in soil ridge) and SRSC-W (plastic film with wire mesh as support embedded in soil ridge)], SR (soil ridge) and NPG (naked polyethylene groove) were conducted in early spring. The results showed that the dynamic changes of ridge root zone temperatures were significantly positively correlated with both inside and outside temperatures of greenhouse. Moreover, daily mean temperatures inside greenhouse and in ridge root zone were increased by 8.07 ℃ and 10.93 ℃, respectively, than temperature outside greenhouse. The effect of greenhouse was more remarkable at night, temperatures inside greenhouse and in ridge root zone enhanced by 9.9 ℃ and 14.81 ℃, respectively, compared with outside temperature. Based on the data analysis, the performance of root zone temperature in terms of preservation of SRSC-W was better than that of SR and SRSC-P at night. And average night temperature were increased by 1.34 ℃ and 0.52 ℃, respectively, compared with those of SR and SRSC-P. The highest root zone temperatures of SR, SRSC-P, NPG and SRSC-W were 28.06 ℃, 27.21 ℃, 29.93 ℃ and 26.05 ℃, respectively, at daytime. This suggested that SRSC-W had the best buffering capacity for high temperature while NPG had the worst buffering capacity. The performance of SRSC in terms of heat storage and preservation under cloudy conditions was worse than that under sunny conditions. Root zone temperature in ridge center of SR was higher than that in lateral ridge at both daytime and nighttime. On the contrary, SRSC-P and SRSC-W had higher lateral temperatures in the daytime and higher center temperature at night. Root zone temperature in north part of ridge was higher than that of south part, and temperature difference was the smallest between south and north under SRSC-W condition. In addition, the lag time for dynamic change in root zone temperature in ridge center was the longest under SRSC-W condition due to powerful temperature buffer capacity. In short, the effect of preservation temperature in root zone of SRSC-W was the best with strongest temperature buffer capacity during low temperature period among all treatments. SRSC-W had a broad prospect for application with low cost and most stable performance of heat storage and preservation.