ISWC OpenIR  > 水保所知识产出(1956---)
温室番茄生长期水分诊断研究
刘 婵
Subtype硕士
Thesis Advisor范兴科
2012-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword番茄 气象因子 冠层叶-气温差 土壤含水率 根系活动层
Abstract

水分是制约作物生长发育的重要环境因子,其对作物的产量和品质有着重要的影响。对于温室大棚作物而言,灌溉是作物获得水分供给的唯一来源,水分的亏缺不仅会使作物品质降低,其对作物的产量也有着深远的影响,因而对于日光温室土壤水分的研究有着重要的意义。虽然目前对于土壤水分诊断的方法有很多种,但通过作物自身的变化来确定土壤水分的变化的指标并不是很多。为了提高作物需水效率的诊断,本文将番茄分为苗期、开花期和结果期三个阶段,确定其各个阶段所需的水分上、下限,研究了番茄全生育期内的冠层叶面温度与土壤含水率和环境因子之间的关系,通过冠层叶-气温差与土壤含水率之间的关系,确定番茄的临界冠层叶面温度,并进一步通过试验研究了番茄冠层叶-气温差与其根系活动层土壤含水率的关系,确定番茄根系的主要吸水区,为农田土壤水分诊断提供科学依据。根据研究结果得出以下结论: 1)番茄冠层叶面温度的变化主要是通过蒸腾作用进行调节的,而环境因子对番茄的蒸腾作用起着一定的调节作用,因而对冠层叶面温度有着一定的影响。本试验主要研究了气温、光照强度、湿度和冠层叶面温度之间的关系,研究表明,温室内环境气温对番茄冠层叶面温度的影响最大,光照强度次之,湿度最小,因而可以确定气温是影响冠层叶面温度的主要环境因子。 2)通过分析番茄不同生育期内的冠层叶面温度日变化,可以得出,冠层叶面温度的日变化规律与气温的日变化基本相似,呈抛物线结构,同时期的冠层叶面温度基本低于气温的变化,冠层叶面温度和气温一般在下午13:00-15:00达到最高值,由于此时的作物蒸腾强度最大,作物需水量与土壤水分之间的供需矛盾最为突出,所以最能反映作物的水分状况,因而选择下午14:00对冠层叶面温度和气温进行观测。
3)日光温室下,番茄全生育期内的冠层叶-气温差的日变化呈曲线分布,冠层叶-气温差的最高值出现在13:00-15:00之间。通过该时期内的数据分析发现,冠层叶-气温差(△T)与土壤容积含水率(SW)呈负相关关系,随着土壤含水率的增加,冠层叶-气温差降低,反之,冠层叶-气温差升高。相关方程式为SW=-0.015△T+0.127,相关系数R2为0.778,并通过数据验证,实测值(Y)与模拟值(X)相关性较好,关系式为Y=0.016+0.941X,相关系数R2为0.723。因此可通过监测13:00-15:00的冠层叶-气温差来了解温室条件下土壤对作物的水分供给状况,为农田土壤水分状况诊断提供科学依据。 4)临界冠层-气温差是指冠层叶-气温差的临界值,该值对于作物水分临界值的诊断具有重要意义。本文主要研究了番茄结果期的临界冠层叶-气温差,对番茄苗期和开花期的临界冠层叶-气温差也做了简单的研究。研究表明,番茄结果期的冠层叶-气温差(△T)与土壤含水率(SW)之间有着较好的负相关关系,两者之间的关系式为SW=-0.014△T +0.130。因而根据方程式并结合临界的土壤含水率即作物在结果期所需的最低含水率(田间持水量的65%)可以确定冠层叶-气温差的最高值为-1.5,即当冠层叶-气温差值大于-1.5时作物开始表现为缺水症状。同理可以确定番茄在苗期和开花期的临界冠层叶-气温差值。 5)根系的生长对作物吸收水分和营养物质具有重要的作用,根系的大小和分布对作物的生长和产量有着重要的影响。研究表明,冠层叶-气温差与不同深度范围内的土壤容积含水率呈负相关关系,且与20-30cm土层内的土壤容积含水率相关性最为显著,相关系数R为-0.808,通过回归分析,得出冠层叶-气温差(△T)与20-30cm土层内的土壤容积含水率(SW)两者之间的回归方程为SW=-0.017△T +0.155,因此可以确定番茄根系的活动层主要分布在土层的20-30cm范围内。 关键词:番茄;气象因子;冠层叶-气温差;土壤含水率;根系活动层

Other Abstract

Water is an important environmental factor restricting the growth of the crops, which has an important impact on the yield and quality of crops. Irrigation is the only source of water supply for greenhouse crops. Moisture deficit will not only reduce the crop’s quality, but also profoundly influence the crop’s yield. Because of this, it is significant to study soil moisture in the greenhouse. Although there are various methods to diagose the soil moisture, the indicators reflecting the change of soil moisture are rare, which are determined by the change of crop itself. In order to improve the diagnosis of the efficiency of crops’ water requirement, the whole of the tomato’s growth period is divided into three parts: seeding, flowing p and fruiting period, and the upper and lower limits of water requirement are also determined during each period. Besides, we also study the relationship among the canopy leaf temperature and soil moisture and the environmental factors in the growth period of the tomato. According to the relationship between canopy leaf-air temperature difference and soil volumetric water content, tomato’s critical canopy leaf tempetature is determined. Furtherly, through studying the relationship between soil volumetric water content and canopy leaf-air temperature difference, the main absorbent area of tomatoes’ root is determined, and supply a scientific basis for diagnosis of farmland soil moisture. The result shows that:
1)The change of canopy leaf temperature is mainly regulated by transpiration. The tomatoes’ transpiration is adjusted by the environmental factors which has a certain impact on canopy temperature. This experiment studied the relationship among temperature, light intensity, humidity and canopy leaf temperature. It shows that the temperature have the greatest effect on the canopy leaf temperature in the greenhouse, which is followed by the  light intensity, and the minimum effect is humidity. Therefore, it can be identified that the temperature is the main environmental factors which affect the canopy leaf temperature. 2)By analyzed the diurnal variation of the canopy leaf temperature in the different growth stages of the tomato, it can get: the canopy temperature change consistently with the temperature, which is parabolic structure, and the canopy leaf temperature is lower than the temperature change in the same period, the canopy leaf temperature and temperature reached the maximum value during 13:00-15:00 for the leaf evapotranspiration being the strongest at this time, the contradiction between supply and demand on the crop water requirement and soil moisture is most prominent, which very easily lead to water shortage of tomatoes. Thus this paper mainly observed the canopy leaf temperature and temperature’s change at 14:00 each day in order to analyze the water supply and demand of the plant. 3)In sunlight green house conditions, there were some peaks in the diurnal curve of canopy leaf-air temperature difference from tomato’s seeding stage to fruiting period, and the maxmum of canopy leaf-air temperature difference’s value appear during 13:00-15:00 each day. Accoding to the data at 13:00-15:00 which in tomato’s main growth period, We can get a result which is the △T has a negative relationship with water content(SW), with the increase of soil moisture, canopy leaf-air temperature difference reduced, on the contrary, the canopy leaf-air temperature difference increased. The related equation is SW=-0.015△T+0.127,correlation coefficient R2 is 0.778, After validated with the measured data, it was found that the measured SW (Y)was well correlated with the simulated one(X), the related equation is Y=0.016+0.941X,and the correlation coefficient R2 is 0.723. Therefore, we could get scientific basis for diagnosis of farmland soil moisture from the water status data which was monitored from canopy leaf-air temperature difference at 13:00-15:00.
4)Threshold of the canopy leaf –air temperature difference refers to the critical value of the canopy leaf –air temperature difference. The value has a great significance for the diagnosis of the critical value of the crop water. This paper has analyzed threshold of the canopy leaf –air temperature difference during the tomato’s fruiting period, and also has done a simple research on the tomato’s seeding and flowering period. The results show that there is a good linear negative correlation between canopy leaf –air temperature difference  (△T )and soil water content (SW), and the equation is: SW=-0.014△T +0.130. It can be determined that the maximum of the threshold of the canopy leaf –air temperature difference is -1.5 according to the equation combined the critical soil moisture content which is the minimum of water content in the fruiting period (65% of the field capacity). That is, the plant will be in the state of water shortage when the △T is greater than or equal to -1.5. It can similarly defined that the threshold of the canopy leaf –air temperature difference of tomato’s seeding and flowering. 5)The growth of root has an important role in the crop’s water and nutrients absorb, Its growth and the distribution play an important role in water use and yield. The result showed that the canopy leaf-air temperature difference (△T) was negatively correlated to the difference depths of the soil volumetric water content(SW), At the same time, there has been the most significantly linear negative correlation in the range of 20-30cm depth, and the correlation coefficient is -0.808. By regression analysis, the equation is SW=-0.017△T+0.155. Thus, it also could be concluded that active zoon of tomatoes’ root is mainly distributed in the range of 20-30cm depth. Key words: tomato; meteorological factor; canopy leaf-air temperature; soil volumetric moisture content; root zone

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8928
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
刘 婵. 温室番茄生长期水分诊断研究[D]. 北京. 中国科学院研究生院,2012.
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