Reclamation of a calcareous saline-sodic soil using phosphoric acid and by-product gypsum

Abstract

Phosphoric acid is increasingly used as a source of water‐soluble P, but it has not been widely tested for its effectiveness in reclaiming calcareous sodic and saline‐sodic soils relative to chemically equivalent rates of gypsum. In lysimeters experiments, we showed that a calcareous saline‐sodic soil can be ‘reclaimed’ using phosphoric acid and leaching with moderately saline irrigation water (sodium adsorption ratio = 4.1 and electrical conductivity = 2.2 dS/m). Phosphoric acid (50% pure) was dissolved directly in the leaching water at application rates of 450, 600 and 900 kg/ha, and phosphogypsum (80% pure) was mixed with soil prior to leaching at application rates of 15, 20, 30 and 40 t/ha. Phosphoric acid was more efficient than the chemical equivalent of phosphogypsum in improving soil hydraulic conductivity, and in reducing the exchangeable sodium percentage (ESP). The ESPs after leaching were: 10 (water only), 5.5–5.3 (phosphoric acid) and 8.2–5.9 (phosphogypsum).

First and second-year assessments of the rapid reconstruction and re-vegetation method for reclaiming two saline–sodic, coastal soils with drip-irrigation

“…Traditional methods such as engineering, mechanical, chemical and biological to reclaiming saline soils for landscape reconstruction have been found ineffective due to high costs or water limitations (Ahmad et al, 1986;Gharaibeh et al, 2010;Li et al, 2015). And using them to create an attractive landscape in a short time and maintain good plant growth was difficult.…”

“…Over time, gypsum (Ahmad et al, 1986;Gharaibeh et al, 2010;Hanay et al, 2004;Joshi and Dhir, 1990;Mahmoodabadi et al, 2013;Miranda et al, 2011;Sidhu et al, 2004;Vander Pluym et al, 1973), sulfuric/phosphoric acid (Gharaibeh et al, 2010;Mahmoodabadi et al, 2013;Yazdanpanah and Mahmoodabadi, 2013), fly ash (Angin et al, 2011), phosphogypsum (Agar, 2011), municipal solid waste (Hanay et al, 2004), polyvinyl-alcohol (Nawar and Petch, 1987) and organic matter Miranda et al, 2011;Somani, 1981;Yu et al, 2010) have been used for soil reclamation. These amendments can effectively improve physical and chemical qualities of saline-sodic soil.…”

Uso de resíduos de gesso como corretivo em solo salino-sódico

“…Contudo, com relação à aplicação de gesso jazida, os resultados aqui encontrados se assemelharam aos observados por Leite et al (2010), quando utilizaram gesso de jazida e ácido sulfúrico, na recuperação de solo salino-sódico proveniente de Condado (PB), concluindo que a aplicação de gesso de jazida ao solo promoveu redução de 79% no teor de sódio solúvel, sendo que este corretivo, associado a uma lâmina de lixiviação, foi mais eficiente do que o ácido sulfúrico, na lixiviação deste íon. Gharaibeh et al (2010) , quando se utilizou o gesso de jazida e o resíduo de gesso, respectivamente.…”

“…Os solos afetados por sódio são comuns em zonas áridas e semiáridas, sendo caracterizados pela presença de sódio em concentrações tão elevadas que ocorre a destruição da estrutura do solo, acarretando a diminuição da taxa de infiltração da água no solo, reduzindo, assim, a produção agrícola (Leite et al 2007, Jalali & Ranjbar 2009, Gharaibeh et al 2010, Tavares Filho et al 2012.…”

Chemical forms of cadmium in a calcareous soil treated with different levels of phosphorus-containing acidifying agents

“…MAP is an acidifying fertiliser that is often used in the blending of dry agricultural fertilisers and it can supply the soil with N and P in plantavailable forms. Phosphoric acid is increasingly used as a source of water-soluble P and is an acidifying agent that can enhance P availability in calcareous soils (Gharaibeh et al 2010). The objectives of the present study were to evaluate the impact of the two P-containing acidifying agents (MAP and phosphoric acid) on soil pH and chemical transformations of Cd in calcareous soil and to study the potential factors affecting the chemical transformation of Cd in an incubation experiment.…”