Physiological responses of arugula/nirá intercropping under different arrangements and growing seasons

ABSTRACT In intercropping between vegetable species, little is known about physiological responses. Thus, getting to know the physiological behavior of these crops is essential to define whether the species are efficient. The aim of this study was to evaluate the physiological responses of arugula/nirá intercropping under different arrangements and growing seasons. The experiment was conducted in a randomized block design, in a split-plot scheme, using the following cultivation arrangements: T1 = arugula monocropping; T2 = two rows of arugula with three rows of nirá (2R:3N); T3 = two rows of arugula with two rows of nirá (2R:2N); T4 = two rows of arugula with one row of nirá (2R:1N), in plots and growing seasons in the subplots (July 24th and September 3rd). We evaluated net photosynthesis rate, stomatal conductance, transpiration, internal carbon concentration, water use efficiency, leaf area and productivity. The highest rates of net photosynthesis were obtained in 2R:3N arrangement in the first growing season. Transpiration, stomatal conductance and internal carbon concentration were lower in the second growing season. The intrinsic and instantaneous water-use efficiencies were higher in the second growing season. Arugula monocropping and the 2R:1N arrangement reached similar productivity. The physiological responses of arugula were not influenced by the nirá cultivation arrangements, indicating that the crop can be arranged without harming the efficiency of the photosynthetic process. The 2R:1N intercropping allowed the best productive performance in the first growing season.

摘要：针对蔬菜物种间套作体系的生理响应相关研究仍较为匮乏，因此明晰此类作物的生理表现是判定其种植效能优劣的关键前提。本研究旨在探究不同配置模式与种植季下，芝麻菜（arugula）与尼拉菜（nirá）间套作的生理响应特征。试验采用裂区-随机区组设计，以栽培配置模式为主区，种植季（分别为7月24日与9月3日）为副区，共设置4种栽培模式：T1为芝麻菜单作；T2为2行芝麻菜配3行尼拉菜（2R:3N）；T3为2行芝麻菜配2行尼拉菜（2R:2N）；T4为2行芝麻菜配1行尼拉菜（2R:1N）。本试验测定了净光合速率、气孔导度、蒸腾速率、胞间二氧化碳浓度、水分利用效率、叶面积与作物产量。试验结果显示：首个种植季中2R:3N配置模式下的净光合速率最高；第二个种植季的蒸腾速率、气孔导度与胞间二氧化碳浓度均显著低于首个种植季，而内在水分利用效率与瞬时水分利用效率则在第二个种植季中表现更优；芝麻菜单作与2R:1N配置模式的产量无显著差异；芝麻菜的生理响应不受尼拉菜栽培配置模式的影响，表明该间套作模式不会损害光合过程的运作效能；2R:1N间套作模式在首个种植季中实现了最优的生产性能。