The Effect of Long Term Irrigation by Treated Effluent on Boron Accumulation in Soil and Citrus Plants

Abstract

The aim of the current research is to assess the long term effect of boron concentration in treated wastewater on citrus plants cultivated in various soil textures. Boron concentrations of treated wastewater used in sandy and clay soil were 1.45±0.37 and 1.03±0.45 mg/l, respectively. In sandy soil, Boron concentrations were 0.53 ± 0.15 and 3.94 ± 0.97 mg/ kg soil showed significant variation at p < 0.05 between the top 0-30 and the second layer 30-60 cm, respectively, while the leaves of citrus have boron concentration of 104.1 mg/kg dry weight. In clay soil boron concentrations were 0.79 mg/kg in both soil layers and in citrus leaves was 267.1 mg/kg dry weight which slightly exceeds the recommended limits 250 mg/kg dry weight. Therefore, the fate of Boron depends mainly on the soil texture; in the sandy soil leaching to deeper layers is occurred, while boron is accumulated in clay soil and citrus leaves. Thus, the municipal treated wastewater could be used safely to irrigate citrus cultivated in sandy soil textures.

Short-Term Response of Young Mandarin Trees to Desalinated Seawater Irrigation

“…The B 3+ concentration in the irrigation waters exceed the maximum threshold proposed for citrus [4,31] (0.5 mg/L; Table 1). In this context, Abu-Daba'an and Al-Najar [38] irrigated a citrus orchard for ten consecutive years with a treated effluent with a B 3+ concentration of 1.03 ± 0.45 mg/L and did not reach toxic levels for B 3+ leaf concentration. However, they also concluded that, since B 3+ is accumulative, if the same irrigation water is used for 30 years, leaf B 3+ concentrations could reach that harmful level.…”

Impact of boric acid and saline water irrigation on germination and seedling establishment of wheat*

“…Recycled wastewater contains a significant level of sodium and boron (Feigin, Ravina, & Shalhevet, 1991;Rehman & Cheema, 2017;Abu Daba' & Al-Najar, 2018), affecting its use for irrigation, especially for sensitive plants. Such ions are potentially harmful to plants, and crop production and long-term soil sustainability can be jeopardized without effective soil and water management.…”

“…Boron and NaCl are commonly found in irrigation water (Abu-Sharar, Hani, & Al-Khader, 2014;Abu Daba' & Al-Najar, 2018). The aim of this research is to determine whether the presence of both boron and NaCl in water in high concentrations inhibits the germination and growth of wheat seedlings or to determine if one factor has an antagonistic relationship with the other.…”