CONSUMPTION, EFFICIENCY AND WATER CONTENT OF ARUGULA UNDER DIFFERENT MANAGEMENT OF BRACKISH NUTRITIONAL SOLUTIONS

ABSTRACT The need to use strategies for using brackish water in agriculture, especially in semi-arid conditions, is evident. Based on this information, this study was developed with the aim of evaluating the consumption, efficiency and water content, as well as the dry mass of the arugula plants (cv. Broad Leaf) exposed to brackish nutrient solutions as a function of replacement strategies and circulation frequencies. The treatments consisted of six salinity levels of the nutrient solution (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 dS m-1) and two circulation frequencies (twice a day 8 a.m. and 4 p.m., and three times a day at 8 a.m., 12 p.m. and 5 p.m.). In Experiment I, the evapotranspiration line was replaced with the respective brackish water used in the preparation of the solution, and in Experiment II, the water supply was used. In both treatments, the experimental design was completely randomized, in a 6 x 2 factorial scheme, with five replications. The conclusion is that it is technically feasible to circulate the nutrient solution twice a day and there were lower losses in the water relations, in the biomass production of the shoot and in the partition of photoassimilates when the replacement with water supply was adopted.

摘要 农业生产中咸水利用策略的需求尤为凸显，尤其在半干旱环境下。基于此背景，本研究旨在评估暴露于咸水营养液下的宽叶芝麻菜（cv. Broad Leaf）的耗水量、水分利用效率、植株含水量以及地上部干物质质量，探究其与营养液替换策略及循环频率的关联。试验设置6个营养液盐度水平（1.5、3.0、4.5、6.0、7.5和9.0 dS·m⁻¹）与2种循环频率：每日两次（上午8时与下午4时）、每日三次（上午8时、中午12时与下午5时）。试验一中，以配制营养液所用的对应咸水补充植株蒸散耗水量；试验二中，则采用常规供水进行水分补充。两组试验均采用完全随机设计，设置6×2因子组合，共5次重复。研究结果表明，每日循环两次营养液在技术上具备可行性；且当采用供水补充方式时，植株水分关系、地上部生物量积累以及光合产物分配的损耗均更低。