节点文献
巨型塑料大棚边际效应初步研究
Preliminary Studies on Marginal Effect in Wide-span Plastic Covered Tunnel Greenhouse
【作者】 霍颖君;
【作者基本信息】 河南农业大学 , 设施栽培, 2009, 硕士
【摘要】 随着现代化设施农业的发展,设施大型化是发展的必然趋势。本实验对新型园艺设施巨型塑料大棚的环境因子尤其是边际区域环境因子进行定期观测,并同步观测边际和中部作物的生长状况,分析秋冬和早春季节巨型塑料大棚边际环境因子的变化状况及对作物产生的影响;通过对东侧不同区域土温、气温、照度、风速等数据的分析,找出了边际土温的界点和各环境因子的变化特点,为更好的研究巨型塑料大棚边际效应和真正提高土地利用率与性价比提供理论依据。具体结果如下:1.边际土温的研究结果东侧边际土温界点在不同时期不同,2008年11月中旬,东侧南部土温界点距东底脚705cm,边际效应已存在。12月中、下旬,土温低温变温界点处于测点3,距东侧295cm。到最冷的2009年2月中旬,边际效应区域与2008年11月中旬相似。2009年3月下旬,此界点距东底脚295cm,处于作物的第二种植行,边际效应影响范围在缩减。南部土温界点在一天内不同时段也不同:最远土温界点出现在08:00-10:00,最近界点出现在16:00-18:00,这与土壤温度最大值和最小值的出现时间十分吻合。一天中最远界点与最近界点相距545cm,南部土壤温度昼夜温差大。东侧中部土温界点在不同时期不同:2008年11月中旬到12月上旬,土温界点徘徊在测点6至7,边际效应已经存在;12月下旬,界点位于第2测点,距东侧160cm,随后又远离东侧2009年2月上旬,界点为测点7,距东底脚705cm。到3月中、下旬,此区土温界点距东底脚100cm,尚未到达种植区,边际效应的影响已不存在。中部土温界点在一天内不同时段也不同:最远土温界点出现在02:00-0 6:00,是第7个测点,距东底脚705cm,最近界点是第1个测点,距棚东侧100cm,出现时间达6个小时。从18:00起,界点又开始向内延伸。要重视东侧中部边际土温在夜间对大棚环境及作物的影响。东侧北部土温界点在不同时期变化不同,08年11月中旬到12月上旬,界点为第7个测点,距离东侧705cm,作物的边六行都已在低温区内。随着外界气候的改变而出现不同的低温变温界点,整体上低温变温界点距东侧较远,距东底脚705cm(第7个观测点),北部边际种植的作物很长一段时期处于土温低温的影响范围之内。东侧各部土温界点在不同时期变化趋势基本相同;到2009年3月下旬东侧的南、中、北部土温低温变温界点基本位于测点3附近,中部和北部日变化呈相同趋势,南部界点出现的最大值和最小值均比中部和北部滞后一个时段。2.边际气温的变化东侧边际区域气温的日变化趋势与室外同高度气温的变化趋势一致。正午前后气温高,早晚气温低。阴天变化趋势较缓且稳定,表现为中部﹥南部﹥北部;晴天,14:00时棚外与棚内北部的温度达到最高值,而中、南部气温最高值则出现在12:00。早晨06:00气温均达最低值,此后东侧气温整体开始上升.观测日的傍晚至次日08:00,中部的气温都略高于南、北部的,从08:00—16:00则情况正好相反。由于受辐射等因素影响较大,气温随测点的变化情况比较复杂,没有确定出明确的界点。3.巨型塑料大棚边际光照度的变化巨型大棚内东侧不同部位边际冠层光照度日变化均呈单峰曲线,峰值均出现在12:00左右。棚内外光照度变化一致,随太阳高度的升高而增大、太阳高度的降低而减弱,棚内光照度的变化较棚外平缓。各部位边际冠层光照度的日变化随时间的变化而不同。4.巨型塑料大棚边际效应对作物的影响从株高、茎粗、LAI等方面进行观测,东侧南部的作物较中部和北部的高,并且各部相应的中间对照值相对较高。东侧北部的茎粗总体而言均较中部和南部小,中部的增长率相对较高,植株较粗壮。5.巨型塑料大棚内风速的变化在不通风的情况下,棚内风速变化很小。总体趋势:上午11:00前后风速较大,早晚风速较小。其水平分布,以中心部位较小,边缘相对较大。棚内垂直方向上风速受棚内上下温差造成的热压作用的影响而不同。大棚中风速在南北方向的水平分布规律为:大棚内南部和中部的风速差异不大,北部风速明显大于南部和中部;在东西方向的水平分布规律为:中间测量点的风速小于东、西部测点的风速,东部风速较大。大棚内的风速在水平方向的分布规律为南北方向变化不大,东西方向呈半V字型分布。
【Abstract】 With the development of modern facility agriculture, the large-sized facility is an imperative trend. The wide-span plastic covered tunnel greenhouse is becoming the new favorite of gardening facility. This study observed environmental factors especially marginal environmental factors, and the Conditions for growing of crops which in the marginal and center area grows; analyzed the change of marginal environmental factors and the effects to the crops in autumn-winter and early-spring. By analyzing the data of soil temperature, air temperature, illumination, air speed in the east, we found out the boundary point of marginal soil temperature and characteristics of the various environmental factors, provided basic theory for the studying of wide-span plastic covered tunnel greenhouse marginal effect and improving land utilization rate and Performance-to-price ratio in deed. The concrete results are as follows:1. Results of marginal soil temperature:The soil temperature boundary points of east side were various at different observing period, the distance from soil temperature boundary point of southeast side to east in the wide-span plastic covered tunnel greenhouse was 705cm in the middle ten-day of November 2008,the marginal effect had been existed.The number of soil temperature boundary point was 3,the distance to east was 295cm in the middle ten-day and the last ten-day of December,2008.the soil temperature boundary point of southeast side to east base of the plastic covered tunnel greenhouse was 295cm in the middle ten days of February, 2009, there were the same border area with the middle ten-day of November, 2008. And the point existed in the second cultivation line in the last ten-days of March, 2009, the marginal effect reduced. The soil temperature boundary points of southeast side were various at different times in a day: the farthest soil temperature boundary point appeared in 08:00-10:00, the nearest boundary point appeared in 16:00-18:00, which keeps the same steps with the maximum and minimum values of soil temperature. The distance between farthest soil temperature boundary point and the nearest boundary point was 545cm, which shows that the temperature between day and night was high in soil temperature. The soil temperature boundary point of center in the east were various at different observing period: The marginal effect had been existed from the middle ten-day of November to the first ten- day of December, 2008, the soil temperature boundary point was the number of 6 or 7. The soil temperature boundary point was 2 ,the distance to east was 160cm in the last ten-day of December,2008.Later the soil temperature boundary point began to depart the east. The soil temperature boundary point was 7,the distance to east was 705cm in the first ten-day of February,2009.The middle ten-day or the last ten-day of March, 2009, the soil temperature boundary point was 100cm to east, the marginal effect did not exist. The soil temperature boundary points in center of the east were various at different period of a day: the farthest soil temperature boundary point appeared in 02:00-06:00 and the distance was 507cm to the east, the nearest boundary point appeared in 12:00-18:00 and the distance was 100cm to east, which in this period marginal effect did not exist. The temperature boundary point away from the east. So attention should be paid to the effects of marginal soil temperature to crops.The changes of soil temperature boundary point of northeast was: the boundary point was 7, it was 705cm to the east in the middle of ten-day of November to the first ten-day of December, 2008, and there were six lines of crops growed in the low area. As long as the change of climate, the soil boundary point changed. All in all, the crops which growed in the area would be affected by marginal effect in a long time.The change of soil temperature boundary points in east side were similar. It had levelled at around 3 by the last ten days of March, 2009; scenarios in the centre and north were the same; maximum and minimum values appeared in the south were lagged one period compared with the centre and north.2. Results of marginal air temperatureThe daily change trend of marginal air temperature in the east side was similar with the same height outside. The air temperature was high at noon, and it was lower in morning and night.The change trend was muted and stable in cloudy,it was middle part﹥south part﹥north part;In sunny,outside and the northeast of plastic shelter was the highest level, and the highest appeared at 12:00,whith the center and north of the east side.In 06:00,the air temperature attained the lowest,and later the air temperature began to rise.From nightfall to 08:00 of next day, the air temperature of center in the east was higher than the north and south,and the situation was opposite from 08:00 to 16:00. The change of air temperature with the measuring point was relatively complex affected by radiation, so it’s very difficult to determine the boundary point.3. Results of illuminationThe daily change of marginal illumination was a single peak curve in east side of the wide-span plastic covered tunnel greenhouse, and the maximum value appeared at about 12:00. There were similar trends in and out of wide-span plastic covered tunnel greenhouse. When the solar height is big, the illumination enhanced, when the solar height is small, the illumination reduced, and the change of illumination in the plastic covered tunnel greenhouse was flat.Then, the daily change of marginal illumination of east at the wide-span plastic covered tunnel greenhouse was affected by the times of a day .4. Results of marginal cropThe growth vigor of the middle cucumber was better than marginal, this can be found from plant height, stem diameter and LAI, which indicated that the influence of marginal effect to crop was quite distinct.the cucumber’s vigor was better than the south and north, which grow in middle of the east side. The stem was thinner than the south and center of the north, and the growth rate was bigger ,so the crops was more hairchested which growed in the center of the east.5. Result of air speed researchThe change of air speed was very small when had no wind. The overall tendency assumes: in 11:00 around air speed was bigger than in the morning and night. In level distribution, it was small in the central spot and edge is relatively bigger. In the vertical direction, air speed overall change tendency was that the air speed increased along with the temperature difference caused by heights.The distributing rule of air speed in the north and south direction: the air speed was similar in the south and the middle, and it was bigger in the north than in the south and middle. The distributing rule of air speed in the east and west direction: the air speed in the middle was smaller than in the east and west, the east air speed was bigger. The distributing rule of air speed in horizontal direction level: there was little change in north-south direction, east-west direction was half V-shaped distribution.
【Key words】 wide-span plastic covered tunnel greenhouse; marginal effect; soil temperature boundary point; environmental factors;
- 【网络出版投稿人】 河南农业大学 【网络出版年期】2010年 06期
- 【分类号】S625
- 【被引频次】4
- 【下载频次】117