Irrigation with saline water in soybean (Glycine max (L.) Merr.) in a soil with bovine biofertilizer

ABSTRACT Salinity is a complex phenomenon that affects the metabolic processes of the plant, changing the physiological and biochemical parameters. In this context, the objective of this study was to evaluate the effect of irrigation water salinity on growth, biomass and gas exchanges in soybean crop in soil with and without biofertilizer. The experiment was carried out in a greenhouse at the experimental area of the Agrometeorological Station of the UFC, Fortaleza, CE, Brazil, from May to June 2016. The treatments were distributed in randomized blocks in a 5 × 2 factorial scheme, corresponding to the levels of irrigation water salinity: 0.8; 1.6; 2.4; 3.2 and 4.0 dS m-1, in soil without and with bovine biofertilizer, in five replicates. The following variables were evaluated: growth (plant height, number of leaves, stem diameter, and leaf area), biomass (leaf, root and total dry matter) and gas exchanges (photosynthesis, stomatal conductance and transpiration). Irrigation water salinity reduced photosynthesis, stomatal conductance and transpiration, but with less intensity in the plants that received bovine biofertilizer. The aerobically fermented bovine biofertilizer attenuates saline stress on the initial growth and biomass of soybean plants.

摘要：盐分是一类复杂的环境胁迫现象，可干扰植物代谢过程，改变其生理与生化指标。本研究旨在探究灌溉水盐分对施加与未施加生物肥料（biofertilizer）的土壤中大豆生长、生物量及气体交换特性的影响。

实验于2016年5月至6月间，在巴西塞阿拉州福塔莱萨市UFC农业气象站实验区的温室中开展。实验采用5×2因子设计的随机区组排列，设置5个灌溉水盐分梯度：0.8、1.6、2.4、3.2及4.0 dS·m⁻¹，分别在未施加与施加牛源生物肥料的土壤中进行，每组设置5次重复。

本研究测定的指标包括：生长指标（株高、叶片数、茎粗与叶面积）、生物量指标（叶片、根系及总干物质重量）以及气体交换指标（光合速率、气孔导度与蒸腾速率）。结果表明，灌溉水盐分胁迫会抑制大豆的光合速率、气孔导度及蒸腾速率，但施加牛源生物肥料的植株受抑制程度显著降低。好氧发酵型牛源生物肥料可缓解大豆苗期生长与生物量积累过程中所受的盐分胁迫。