CAJ | 학술논문

根际高温是影响夏季蔬菜集约化育苗主要障碍因子之一，水冷苗床是根际降温的一种有效方式。为了科学利用水冷苗床这一根际降温装置，该文以水冷苗床作为根际降温方式，设置了5个不同的降温时段，依次为M1（07：00－11：00）、M2（11：00－15：00）、M3（07：00－19：00）、M4（19：00－07：00）和M5（全天降温），以根际不降温的苗床为对照。研究了水冷苗床不同时段的根际降温效果及对番茄幼苗生长的影响。结果表明：水冷苗床任一时段根际降温均降低了番茄幼苗根际日均温和最高温度，其中处理M3（07：00－19：00）和处理M5（全天降温）降温效果最为显著，番茄幼苗根际日均温分别为23.6和22.6℃，比对照苗床依次降低了3.3和4.3℃。根际温度变化幅度受冷水循环时间及时段的影响，M4（夜间降温）处理番茄幼苗根际温度日变化曲线波动大于其他处理，番茄幼苗根际温度日较差达到10.3℃，而M3（白天降温）处理番茄幼苗根际温度日较差仅有1.7℃。所有降温处理均提高了番茄幼苗干物质积累和单株叶面积，其中 M5（全天降温）和 M3（07：00－19：00）这两个处理番茄幼苗单株干质量和叶面积均显著高于对照（P<0.05）。与对照相比，M3处理番茄幼苗的茎粗与壮苗指数分别增加了35.1%和39.5%。所有根际降温处理增加了根系总长和根系表面积，提高了叶片叶绿素含量和根系活力。从节能和培育壮苗的效果综合考虑，水冷苗床M3（07：00－19：00）白天降温是一种科学的降温方法。
근제고온시영향하계소채집약화육묘주요장애인자지일，수랭묘상시근제강온적일충유효방식。위료과학이용수랭묘상저일근제강온장치，해문이수랭묘상작위근제강온방식，설치료5개불동적강온시단，의차위M1（07：00－11：00）、M2（11：00－15：00）、M3（07：00－19：00）、M4（19：00－07：00）화M5（전천강온），이근제불강온적묘상위대조。연구료수랭묘상불동시단적근제강온효과급대번가유묘생장적영향。결과표명：수랭묘상임일시단근제강온균강저료번가유묘근제일균온화최고온도，기중처리M3（07：00－19：00）화처리M5（전천강온）강온효과최위현저，번가유묘근제일균온분별위23.6화22.6℃，비대조묘상의차강저료3.3화4.3℃。근제온도변화폭도수랭수순배시간급시단적영향，M4（야간강온）처리번가유묘근제온도일변화곡선파동대우기타처리，번가유묘근제온도일교차체도10.3℃，이M3（백천강온）처리번가유묘근제온도일교차부유1.7℃。소유강온처리균제고료번가유묘간물질적루화단주협면적，기중 M5（전천강온）화 M3（07：00－19：00）저량개처리번가유묘단주간질량화협면적균현저고우대조（P<0.05）。여대조상비，M3처리번가유묘적경조여장묘지수분별증가료35.1%화39.5%。소유근제강온처리증가료근계총장화근계표면적，제고료협편협록소함량화근계활력。종절능화배육장묘적효과종합고필，수랭묘상M3（07：00－19：00）백천강온시일충과학적강온방법。
The growth and physiological metabolism of plant are greatly affected by root-zone temperature. The heat stress around root zone in hot summer is an important factor limiting the seedling growth. Compared with air temperature cooling, root-zone cooling is more economical and is an effective solution to alleviate high temperature stress. A new water-cooled seedling bed (WSD) has been proved to be an effective method to lower the root-zone temperature. In order to utilize WSD scientifically, 5 different root-zone cooling periods were designed using the WSD device for root-zone cooling of tomato (Solanum lycopersicum) seedling. The 5 different root-zone cooling periods were as follows: M1 (cooling from 7:00 to 11:00), M2 (cooling from 11:00 to 15:00), M3 (cooling from 7:00 to 19:00), M4 (cooling from 19:00 to 7:00) and M5 (cooling all day). Non-cooling seedling bed was used as control. The objective of this study was to investigate the cooling effect of the WSD under 5 different root-zone cooling periods and its effect on the growth of tomato seedling. The root-zone temperature, seedling growth, root morphological traits and physiological characteristics of tomato seedling were tested. The results showed as follows: The root-zone daily mean temperature and daily maximum temperature of tomato seedlings under 5 cooling periods of the WSD were all lower than those under the non-cooled seedling bed (CK) during tomato seedling period. The cooling effect of the WSD was significantly (P<0.05) correlated with cooling duration and cooling period. Compared with cooling during night, mean temperature in the daytime, daily mean temperature and maximum temperature for the treatments cooling during the day time were lowered significantly (P<0.05). Compared with other treatments, the treatment M3 (cooling from 7:00 to 19:00) and M5 (cooling all day) got the best cooling effects. The daily mean root-zone temperatures of tomato seedlings under M3 and M5 were 23.6 and 22.6℃respectively, which were lowered by 3.3 and 4.3℃ respectively compared with CK during tomato seedling period. The daily variation of root-zone temperature of tomato seedlings was affected also by cooling duration and cooling period. Root-zone temperature of treatments cooling during the day time showed a small variation, while root-zone temperature of treatments cooling during the night got a big fluctuation. The daily variation of root-zone temperature under M4 was maximum among all treatments and its diurnal temperature range reached 10.3℃.In contrary, the daily variation of root-zone temperature under M3 was minimum among all treatments and its diurnal temperature range was only 1.7℃.Dry mass and leaf area per plant of tomato seedling in 5 treatments were enhanced significantly, of which the differences of the 2 growth indices between M3, M5 and CK reached significant level (P<0.05). Tomato seedling stem diameter and healthy index under the M3 treatment were improved by 35.1% and 39.5% respectively compared with the CK treatment. Total length of root, toot surface area, chlorophyll content and root activity were all improved in the 5 treatments. Considering the factors such as energy conservation and strong seedling culturing, root zone cooling from 7:00 to 19:00 (M3) is an effective way for the scientific utilization of water-cooled seedling bed.