Atriplex nummularia Lindl. represents a cost-effective alternative for improving salt-affected soils in arid and semiarid environments due to its high adaptability to salinity and water deficiency. This study aimed to investigate soil physical-chemical changes in response to A. nummularia cultivation under field condition. Additionally, we quantified its biomass yield and phytoextraction potential. Two treatments were evaluated: soil cultivated with Atriplex under two crop densities (1 × 1 and 2 × 2 m), and a control (bared soil) with four replicates. The samples were taken at three soil depths (0-5, 15-20, and 40-45 cm). In general, dry biomass yield for leaves, stems and roots, as well as the bulk density and the hydraulic conductivity of the soil were sensitive to crop densities. Thus, the use of A. nummularia can be recommended for phytoremediation of salt-affected soils, as well as to improve soil physical condition. When it comes to salt phytoextraction per area, we recommend planting A. nummularia at a 1 × 1 m crop density. The greater accumulation of salts was observed in leaves, as observed for Na (82% roughly). However, in order to improve soil physical conditions, we suggest the management of A. nummularia under 2 × 2 m crop density. Pruning was fundamental to increase the biomass yield and, consequently, the phytoextraction of specific ions, e.g., Na, Cl. It was responsible for 83% and 88% of the total dry biomass at 1 × 1 and 2 × 2 m crop density, respectively.

RESUMODesenvolveu-se este trabalho em um Cambissolo salino sódico do Perímetro Irrigado Cachoeira II, Serra Talhada, PE, com o objetivo de avaliar a dinâmica de cátions e ânions básicos em um solo salino sódico submetido a fitorremediação com Atriplex nummularia e correção com aplicação de gesso. Realizaram-se amostragens semestrais com quatro coletas de solo (0, 6, 12 e 18 meses). O delineamento experimental utilizado foi de blocos ao acaso avaliando-se quatro tratamentos: controle (sem nenhum manejo do solo), correção química com gesso (sem cultivo) e dois com cultivo de Atriplex nummularia Lindl (espaçamentos 1 x 1 m e 2 x 2 m), com quatro repetições. Os resultados das análises do solo revelaram a contribuição da aplicação de gesso, especialmente do cultivo de plantas de atriplex na redução dos teores de sais no solo.Palavras-chave: solos afetados por sais, erva-sal, corretivo químico Dynamics of ions in saline-sodic soil under phytoremediation with Atriplex nummularia and gypsum applications ABSTRACT The study was conducted in a saline-sodic Inceptisol from the Cachoeira II Irrigation Perimeter, Serra Talhada (PE), with the objective of evaluating the dynamics of basic cations and anions in a saline-sodic soil subjected to phytoremediation with Atriplex nummularia and correction with application of gypsum. Samples were taken every six months, at four times (0, 6, 12 and 18 months). The experimental design was in randomized blocks, the four treatments evaluated were: control (without any management practice), chemical correction with gypsum (no crop) and two Atriplex nummularia cultivation (1 x 1 m and 2 x 2 m plant spacing), with four replications. The results of soil analysis revealed the contribution of gypsum application and especially the cultivation of Atriplex plants in reducing the levels of salts in the soil.

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Sorghum bicolor (L.) Moench, one of the most important dryland cereal crops, is moderately tolerant of soil salinity, a rapidly increasing agricultural problem due to inappropriate irrigation management and salt water intrusion into crop lands as a result of climate change. The mechanisms for sorghum’s tolerance of high soil salinity have not been elucidated. This study tested whether sorghum plants adapt to salinity stress via stomatal regulation or osmotic adjustment. Sorghum plants were treated with one of seven concentrations of NaCl (0, 20, 40, 60, 80, or 100 mM). Leaf gas exchange (net CO2 assimilation (A), transpiration (Tr); stomatal conductance of water vapor (gs), intrinsic water use efficiency (WUE)), and water (Ψw), osmotic (Ψo), and turgor Ψt potentials were evaluated at 40 days after the imposition of salinity treatments. Plants exhibited decreased A, gs, and Tr with increasing salinity, whereas WUE was not affected by NaCl treatment. Additionally, plants exhibited osmotic adjustment to increasing salinity. Thus, sorghum appears to adapt to high soil salinity via both osmotic adjustment and stomatal regulation.