Agricultural Water Footprint of Southern Highbush Blueberry Produced Commercially with Drip Irrigation and Sprinkler Frost Protection

A study was conducted from 2010 to 2017 to determine the water footprint for producing blueberries in the Entre Ríos province of Argentina. Three cultivars of southern highbush blueberry (hybrid cross of Vaccinium sp.) were evaluated in the study, including “Star”, “Emerald”, and “Snowchaser”. In each case, the plants were irrigated by drip and protected from frost using overhead sprinklers. Water requirements for irrigation and frost protection varied among the cultivars due to differences in the timing of flowering and fruit development. The annual water footprint for fruit production in each cultivar is expressed in units of cubic meters of water used to produce one ton of fresh fruit and ranged from 212 - 578 m3∙t−1 for “Star”, 296 - 985 m3∙t−1 for “Emerald”, and 536 - 4066 m3∙t−1 for “Snowchaser”. “Snowchaser” flowered earlier than the other cultivars and, therefore, needed more water for frost protection. “Star”, on the other hand, ripened the latest among the cultivars and required little to no water for frost protection. Frost protection required a minimum of 30 m3∙h−1 of water per hectare and in addition to drip irrigation was a major component of the water footprint.

巴塔哥尼亚(阿根廷)海洋与河水中腐植酸组成比较

比较了Engao海湾海水(大西洋)和丘布特河水(阿根廷的巴塔哥尼亚)中腐殖质的结构。这些腐殖质被分离、纯化后,通过元素分析法,核磁共振法(13C和1H谱),红外光谱法,紫外吸收法和荧光法等对其结构特性进行了分析鉴定,并以氮含量、氧含量、H/C比、C/N比、红外波段中氮和羧基官能团含量、核磁共振吸收谱线中官能团的斜率系数、250和365nm处的吸收比率(E2/E3)、激发—发射模型和荧光量子产率等指标对二者的相似性进行比较。Engao海湾和丘布特河水中的腐殖质主要由黄腐酸组成。尽管它们具有一定的相似性,都含有较高的直链脂肪碳含量(低芳香烃碳含量),但其差异性也十分显著,二者所含蛋白质和羧酸不同。Engano海湾腐殖质主要来自于水生的植物或动物;丘布特河腐殖质也同样来自于水生动植物,但是也有证据表明它可能来自土壤黄腐酸。