The effects of irrigation water salinity level on faba bean (Vicia faba L.) productivity

Original scientific paper Journal of Central European Agriculture, 2020, 21(3), p.537-542 DOI: /10.5513/JCEA01/21.3.2872 The effects of irrigation water salinity level on faba bean (Vicia faba L.) productivity Učinci razine zaslanjenosti vode za navodnjavanje na produktivnost boba (Vicia faba L.) Lana FILIPOVIĆ (✉), Davor ROMIĆ, Gabrijel ONDRAŠEK, Ivan MUSTAĆ, Vilim FILIPOVIĆ University of Zagreb Faculty of Agriculture, Department of Soil Amelioration, Svetošimunska 25, 10000 Zagreb, Croatia ✉ Corresponding author: Received: April 19, 2020; accepted: May 27, 2020 ABSTRACT In Mediterranean region where seawater intrudes porous karst matrix and salinizes soil and water resources, water used for the irrigation of crops is frequently of inadequate quality. Measuring the productivity of horticultural crops under saline conditions helps to determine whether and when to irrigate crops if water is saline, thus balance between crop water and salt stress. A greenhouse pot experiment was set to study the effects of saline irrigation water on faba bean (Vicia faba L.) biomass and yield parameters. NaCl salinity was applied in a nutrient solution as follows: NaCl0 as control (nutrient solution without added NaCl), NaCl50 (control + 50 mM NaCl), and NaCl100 (control + 100 mM NaCl). Five weeks after salinity treatment started, plant height (cm), number of lateral branches per plant, number of pods and seeds per plant, shoot weight (g), pod weight (g) and seed weight (g) were determined. Compared to control, increased irrigation water salinity statistically significantly decreased measured parameters (P<0.01), except for number of branches and pods. Faba bean productivity decreased proportionally to the irrigation water salinity level, suggesting that optimal saline agriculture management strategy can be to allow for the acceptable yield loss in order to avoid plant water stress. Keywords: saline agriculture, drip irrigation, crop productivity, crop salt stress SAŽETAK Na području Mediterana, gdje dolazi do prodora morske vode kroz porozni krški materijal i zaslanjivanja tala i vodnih resursa, voda koja se koristi za navodnjavanje usjeva često nije odgovarajuće kakvoće. Mjerenje produktivnosti hortikulturnih usjeva u zaslanjenim uvjetima pomaže odrediti može li se navodnjavati zaslanjenom vodom i kada, kako bi se pronašla ravnoteža između vodnog stresa usjeva i stresa soli. Postavljen je pokus u loncima u plasteniku kako bi se istražili učinci zaslanjene vode za navodnjavanje na biomasu i parametre prinosa boba (Vicia faba L.). NaCl sol je primijenjena u hranjivoj otopini kako slijedi: NaCl0 kao kontrola (hranjiva otopina bez dodanog NaCl), NaCl50 (kontrola + 50 mM NaCl), i NaCl100 (kontrola + 100 mM NaCl). Pet tjedana nakon početka tretmana zaslanjenom vodom, izmjerena je visina biljaka (cm), određen broj bočnih izdanaka, mahuna i sjemenki po biljci, masa nadzemnog dijela biljke (g), masa mahune (g) i masa sjemena (g). U usporedbi s kontrolom, povećana zaslanjenost vode za navodnjavanje statistički je značajno smanjila mjerene parametre (P<0.01), osim broja izdanaka i mahuna. Produktivnost boba smanjila se proporcionalno razini zaslanjenosti vode za navodnjavanje, sugerirajući da optimalna strategija poljoprivrednog gospodarenja u zaslanjenim uvjetima može biti dozvoljavanje prihvatljivog gubitka prinosa kako bi se izbjegao vodni stres usjeva. Ključne riječi: poljoprivreda u zaslanjenim uvjetima, navodnjavanje kapanjem, produktivnost usjeva, stres soli usjeva 537 Original scientific paper Filipović et al.: The effects of irrigation water salinity level on faba bean (Vicia faba... INTRODUCTION High crop productivity is an unfeasible objective without the irrigation of crops. In Mediterranean coastal areas seawater frequently intrudes into rivers and aquifers (Zalidis et al, 2002), while surface and groundwater are used as the irrigation water supply. Because of the climatic conditions, agricultural production in these areas is unfeasible without the irrigation (Romic et al, 2008), therefore farmers often use water of poor quality DOI: /10.5513/JCEA01/21.3.2872 which leads to unspecific oxidation of proteins and membrane lipids, causing DNA injuries (Schützendübel and Polle, 2002). Plant salt stress has been frequently studied, usually focusing on certain plant physiological aspects affected by the salinity; however, from the agronomical perspective, it is especially important to conduct research addressing the issue of salinity effect on crop productivity, i.e., growth, development and yield (Sen and Mandal, 2016). (Ondrasek et al, 2006). Irrigation of crops with a low- Faba bean (Vicia faba L.) is a legume crop produced quality water favors secondary salinization of soil, and worldwide, including the Mediterranean area. It is one contrary to its initial purpose, it is limiting the productivity of the major cool season grain legume crops produced of crops (e.g., Askari-Khorasgani et al., 2017). It is worldwide, as its high yield makes it attractive to producers considered that 20 - 50% of the irrigated land worldwide and its high protein content appealing to consumers is affected by the salinity (Pitman and Laüchli, 2002). Use (Merga et al., 2019). Legumes can support biological of saline irrigation water changes soil physical, chemical, nitrogen fixation; thus, they offer an environmentally and biological properties (e.g., Filipović et al., 2018), sustainable source of nitrogen to cropping systems which negatively affects crop development, growth and (Crews and Peoples, 2004). Legumes are usually classified yield. Even though high productivity is the aim of crop as either sensitive or moderately tolerant to salinity. Vicia irrigation, use of irrigation water of poor quality threatens faba (L.) is considered moderately tolerant to salinity, the sustainability of crop production on the irrigated land with a reduction of vegetative growth at irrigation water (Matijević et al., 2014). electrical conductivity of 6 dS m-1 or higher (Al-Tahir and High concentration of soluble salts in the rhizosphere causes plant salt stress. Salt stress instigates water and nutrient imbalances, as well as triggers unspecific oxidation processes in plant cells. Growing in a saline environment is leading to morphological, physiological, biochemical, and molecular changes in plant cells, which negatively affects crop growth and productivity (Wang et al., 2003). Thus, plant salt stress is defined by the osmotic and ionic stress, accompanied with the oxidative stress. High soil Al- Abdulsalam, 1997). Furthermore, Katerji et al. (2000) identified faba bean as moderately sensitive to salinity, possibly less sensitive at later developmental stages (AlTahir and Al-Abdulsalam, 1997). Faba bean has been frequently studied under saline conditions for its nutrient removal, growth performance, water use efficiency and yield (e.g., Katerji et al, 2005; Abdelhamid et al., 2010; (...truncated)