Success of Reclamation Trials of Saline-sodic Soils in Oman Reported

Muscat, Phases 1 and 2 of a research on using special fertilizers for the reclamation of saline-sodic soils in Oman with the aim of finding viable solutions to address soil salinity across the Governorate of South Al Batinah succeeded. The research was conducted by Oman Shell, Shell Agriculture and Forestry and Sultan Qaboos University (SQU).

Oman Shell in collaboration with SQU, carried out a research between 2020 and 2022, to study how effective Special-S (a sulphur fertilizer produced using Shell Thiogro technology) is in remediating saline-sodic soils through soil acidification.

In Phase 1 of the research, incubation trials and column experiments were performed with Special-S on decreasing soil pH (measure of the acidity or alkalinity of the soil), and salt leaching was carried out on five different types of soil collected from different Omani farms. Special-S showed significant acidification of the soil, and was effective in salt leaching, doubling salts leached as compared to control.

Field trials were carried out to evaluate the response of plants to this amendment. With the application of Special-S, there was a 13% increase in yield of Rhodes grass and 59% increase in yield of wheat. The calcium and phosphorous uptake by Rhodes grass plants were 75% and 14% higher respectively as compared to the control category.

In Phase 2 of this research, a socio-economic survey was conducted to understand current Omani farmers’ perception of the soil salinity issue and its management, as well as their willingness to apply new technologies to alleviate soil salinity. Though 62% were not currently using any specific techniques to alleviate salinity, 82% of farmers indicated a willingness to purchase soil amendment to manage soil salinity.

Additionally, improving the active management of soil salinity would increase the sustainability of these farms, and mitigate a myriad of social and economic problems associated with the decay of soil quality and productivity.

Further studies in Phase 2 testified to Special-S effectiveness in leaching salts compared to agricultural gypsum and control, with Special S being 31 – 37% more effective in leaching. Compared with agricultural gypsum, Special-S enables the replacement of Na+ ions without the addition of external Ca2+ ions that are already abundant in Oman’s soils.

With the conclusion of Phase 1 and Phase 2, SQU recommends 1 ton per hectare per year Special-S application on soils with electrical conductivity between 4 – 20 dS/m that experience poor irrigation water quality. Referencing to Oman Salinity Strategy 2012, about 30 - 40% of farms in South Al Batinah meet these conditions.

Walid Hadi, Oman Shell’s Country Chairman, commented on the research saying, “Soil salinity is an increasing concern for South Al Batinah. We have worked together with SQU to conduct critical research which has been a big contributor to a productive and sustainable agricultural sector.” He added, “It has been a privilege to work with the brilliant minds at SQU to meet this real-life challenge facing the industry head-on.”

Zain Hak, Shell’s Global Vice President of Agriculture and Forestry (A&F) said, “Soil salinity puts pressure on existing agricultural communities. As the research with SQU validates, Special-S alleviates soil salinity and increases productivity in farms. This helps address Oman’s food security concerns while empowering Omani farmers to raise their income with more arable land and higher yields.”

He also added, “This research collaboration with SQU is a great example of how Shell A&F continues to look for opportunities to offer sustainable and integrated solutions to meet productivity and emissions related challenges across the agriculture and forestry value chains.”

Dr. Daniel Blackburn, Project Leader from the Department of Soils, Water and Agricultural Engineering of Sultan Qaboos University said, “The salt contamination of agriculture soils in South Al Batinah has been a real agricultural challenge, reducing farm yields and profitability, and in extreme cases, forcing farmers to abandon their lands.”

He further said that, “Our collaboration with Oman Shell represents a fantastic public-private partnership directed at community wellbeing, as we believe that the use of Special-S will provide continuous Sulphur and nitrogen nutrition to crops. This product will aid in the reclamation of salt affected soils, helping in leaching excess sodium salts, whilst decreasing soil alkalinity and improving plant nutrition. With this technology and data from the research results, we hope to make a substantial contribution to the sustainable management of Oman’s soil and to Oman’s food security.”

Source: Oman News Agency