| 摘要: |
| 【目的】研究有机营养液基质袋式栽培条件下，依据称重法决策灌溉量与甜瓜茎流的关系，分析茎流与根际环境因子和温室内空气环境因子的相关性，以及灌溉量对甜瓜养分吸收和产量的影响，为进一步推广称重法决策灌溉量提供依据。【方法】以薄皮甜瓜“千玉6号”为试材，采用盆栽方式，每个处理10盆。每个处理随机选取3盆植株放置在连续称重仪上测定，以获得甜瓜每个处理的蒸腾耗水总量（WET）。从开花期开始进行水分处理，即分别按照WET的80%（T1），100%（T2），120%（T3）对甜瓜进行灌溉，其余正常管理，监测甜瓜生长的空气环境因子（空气温度、空气相对湿度、冠层净辐射、饱和蒸气压差）和根际环境因子（根际含水率、根际电导率）以及不同处理甜瓜的茎流速率，分析茎流速率与空气环境因子和根际环境因子的相关性，并测定了不同处理甜瓜干物质积累、产量及各个器官的全氮（N）、全磷（P）、全钾（K）含量。【结果】晴天甜瓜茎流流速为不稳定的宽型单峰曲线，阴天为双峰曲线，多云转晴情况下为窄型单峰曲线。各处理甜瓜茎流速率表现为T3>T2>T1，而且T3处理的变幅最大。茎流速率与空气环境因子的直接通径系数的绝对值表现为根际电导率>冠层净辐射>根际含水量>空气相对湿度>饱和蒸气压差>空气温度。根际环境因子中，甜瓜根际电导率对茎流流速的直接效应最强；空气环境因子中，冠层净辐射对茎流流速的直接效应最强。晴天不同处理甜瓜茎流总量大于蒸腾耗水总量，且晴天和阴天不同处理的茎流总量差异显著。随着灌溉量的增加，各处理甜瓜蒸腾耗水总量、总鲜质量、产量均表现为T3>T2>T1。3个灌水量处理根、茎、叶中N、P、K含量差异不显著，果实中N、P、K含量差异显著。根中N、P、K含量均表现为T3>T1>T2；茎中N、P含量表现为T3>T2>T1，K含量表现为T3>T1>T2；叶片中N、P、K含量表现为T1>T2>T3；果实中N、P含量表现为T2>T1>T3，K含量表现为T1>T2>T3。【结论】用称重法决策灌溉量属于按需精准灌溉，可以满足基质袋式栽培甜瓜的正常生长。增加灌溉量有益于经济产量的积累，但不利于干物质积累。茎流反映了甜瓜水分从根系运输至各器官的总流量，而蒸腾耗水总量反映了植物实际消耗且所需要补充的水分总量。 |
| 关键词: 甜瓜；灌溉量 茎流 环境因子；养分吸收 |
| DOI： |
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| 基金项目:陕西省重点研发计划项目（2018TSCXL-NY-05-01）;青海省科技计划项目（2018-NK-123）;陕西省农业协同创新与推广联盟项目（LMAD201802） |
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| Effects of irrigation amounts by weighting method on stem flow and nutrient absorption of melon in substrate bag culture |
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REN Ruidan,FAN Binghua,WANG Guipeng,et al
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| Abstract: |
| 【Objective】This paper studied the relationship between the irrigation amount and the stem flow of muskmelon under the condition of organic nutrient solution matrix bag cultivation,and analyzed the correlation between the stem flow and the rhizosphere environment factors and the air environment factors in the greenhouse,as well as the influence of the irrigation amount on the nutrient absorption and yield of muskmelon,so as to provide a basis for the further popularization of the weighing method to determine the irrigation amount.【Method】The thin skin melon “qianyu 6” was used as the test material.Potted plants were used to treat 10 pots each.For each treatment,3 plants were selected and placed on a continuous weighing machine to obtain the daily transpiration water consumption per plant of each treatment of melon,which was denoted as WET.Starting from the flowering period,irrigation was conducted in accordance with 80% (T1),100% (T2) and 120% (T3) of WET,and the normal management of the rest was consistent.Monitoring of muskmelon growth factor of temperature,humidity,air canopy net radiation,vapor pressure deficit and rhizosphere environment factor,the water content,conductivity,and different processing stem flow,nutrient uptake and yield,analysis of stem flow rate and air environment factor and rhizosphere environment factor,and the determination of the different processing melon accumulation of dry matter,yield and total nitrogen(N)、total phosphorus（P）、total potassium（K） elements contents of each organ.【Result】The stem flow of muskmelon was a wide unimodal curve on sunny days,a double peak curve on cloudy days,and a narrow unimodal curve in cloudy clears days.The stem flow rate of each treatment was T3>T2>T1,and the variation of T3 treatment was the largest,showing a trend of increasing first and then decreasing.The direct path coefficient between stem flow rate and environmental factor is the rhizosphere conductivity > net canopy radiation > rhizosphere water content > air relative humidity > vapor pressure deficit > air temperature.The direct path effect of rhzospheric conductivity on sap flow was high.Among air environment,the direct path effect of canopy net radiation on stem flow was high.The total amount of daily stem flow in different treatments was greater than that in daily evapotranspiration on sunny days,and the total amount of daily stem flow in different treatments on sunny and cloudy days was significantly different.With the increase of irrigation,the total daily evapotranspiration,total fresh mass and output of each treatment were T3>T2>T1.The contents of N,P and K in fruits were significantly different from that in roots,stems and leaves among three irrigation treatment.The contents of N,P and K in the root were all shown as T3>T1>T2.The content of N and P in the stem was T3>T2>T1,and the content of K was T3>T1>T2.The N，P and K content in the leaves was T1>T2>T3.The content of N and P in fruits was T2>T1>T3,and K was T1>T2>T3.【Conclusion】The weighing method to determine the irrigation amount belongs to precise irrigation on demand,which can satisfy matrix bag cultivation.Increasing the amount of irrigation is beneficial to the accumulation of economic yield,but not conducive to the accumulation of dry mass.Stem flow can reflect the total water flow rate from the root system to each organ,while evapotranspiration water consumption can reflect the amount of water the plant actually consumes. |
| Key words: melon irrigation amount stem flow environmental factors nutrient uptake |
