负压供水下土壤水分对樱桃萝卜生长及水分利用效率的影响

为探究负压供水下土壤水分对樱桃萝卜生长及水分利用效率的影响，采用盆栽试验，设置-5（T1）、-9（T2）、-14 kPa（T3）三个负压供水压力处理和一个常规浇灌（CK）处理，分析不同水分处理对樱桃萝卜土壤含水量、农艺性状、光合特性、水分利用效率等指标的影响。结果表明：①整个水分处理期间，CK、T1、T2、T3的土壤含水量分别平均为12.60%、12.63%、10.07%和8.47%，其中T1和T2为弱时间变异土壤水分，而T3和CK为中等时间变异土壤水分；全生育期累计灌水量和蒸散量均表现为CK>T1>T2>T3，各处理间均差异显著。②成熟期时，T1、T2、T3三个处理的樱桃萝卜株高、最大叶长、根径、干物质量、根鲜重等指标整体上均随土壤含水量的下降而下降；土壤含水量基本相同的T1和CK处理，前者的最大叶长、根鲜重显著高于后者，但株高、根径、干物质量等无明显差异。③不同处理樱桃萝卜叶片的SPAD值整体上无明显差异，生长前期净光合速率在处理之间没有表现出明显差异，但生长后期T1和T2显著高于CK，T3显著低于CK。④采收后不同处理的根鲜重、干物质量均表现为T1>T2>CK>T3，其中T1、T2显著高于T3，T1的根鲜重较CK显著提高36.09%，T3的根鲜重较CK显著降低42.36%；不同处理的根冠比没有显著差异，在0.95~1.05之间；产量水分利用效率(WUEY)和生物量水分利用效率(WUEB)均表现为T2>T1>T3>CK，T1、T2的WUEY和WUEB较CK分别显著提高了43.42%、57.89%和52.67%、62.00%。综上所述，土壤含水量和土壤水分时间变异性共同影响了樱桃萝卜的生长发育和产量形成，平均含水量基本相同时弱时间变异的土壤水分条件能够促进植株生长发育，显著提高樱桃萝卜的产量及水分利用效率。以上研究结果对进一步明确土壤水分与作物关系具有重要的科学指导意义。

Effect of Soil Moisture on Growth and Water Use Efficiency of Cherry Radish Under Negative Pressure Irrigation

In order to explore the effect of soil water on the growth and water use efficiency (WUE) of cherry radish under negative pressure water supply, pot experiments were conducted to set up three negative pressure irrigation treatments of -5(T1), -9(T2), -14 kPa (T3) and one conventional irrigation (CK) treatment, and the effects of different treatments on soil water content, agronomic traits, photosynthetic characteristics, WUE and other indicators of cherry radish were analyzed. The results showed that: ① During the whole water treatment period, the average soil water contents of CK, T1, T2 and T3 were 12.60%, 12.63%, 10.07% and 8.47%, respectively, of which T1 and T2 were weak time-varying soil moisture, while T3 and CK were medium time-varying soil moisture. Cumulative irrigation and evapotranspiration during the whole growth period were showed CK>T1>T2>T3, with significant differences among the treatments. ② The plant height, maximum leaf length, root diameter, dry matter content and fresh weight of cherry radish in mature stage all decreased with the decrease of soil water content in treatments T1, T2 and T3. For T1 and CK treatments with basically the same soil water content, the maximum leaf length and root fresh weight of the former one were significantly higher than those of the latter one, but there was no significant difference in plant height, root diameter and dry matter content. ③ SPAD values of cherry radish leaves in different treatments showed no significant difference between treatments. In early growth stage, net photosynthetic rate showed no significant difference between all treatments; but in late growth stage, those of T1 and T2 were significantly higher than CK, those of T3 was significantly lower than CK. ④ After harvest, fresh weight and dry weight of roots in different treatments were showed T1>T2>CK>T3, of which T1 and T2 were significantly higher than T3, root fresh weight of T1 was significantly higher than CK by 36.09%, and T3 was significantly lower than CK by 42.36%. Root-shoot ratio of different treatments had no significant difference, ranging from 0.95 to 1.05. WUEY of yield and WUEB of biomass were showed T2>T1>T3>CK. WUEY and WUEB of T1 and T2 were significantly increased than CK by 43.42%, 5789% and 52.67%, 62.00%, respectively. In summary, soil water content and soil moisture time variability affected the growth and yield formation of cherry radish together. When the average soil water content was basically the same, soil moisture with weak time variability could promote plant growth and development, thus significantly improve the yield and water use efficiency of cherry radish. The present research was of important scientific guiding significance for further clarifying the relationship between soil moisture and crops.