Issue 10 2019
13th IPI-CAU-ISSAS International Symposium in Kunming, China:
Polysulphate hits all the senses


What is one of the best ways to make a memorable impression? The answer is to engage the senses. By way of an example, this edition of the Polysulphate Missive takes you to China. We want you to share all that there was to see, hear, smell, taste and touch on the subject of balanced crop nutrition at a major fertilizer event.

Feeding the global appetite for balanced crop nutrition advice

The 13th International Symposium had the theme “Potash and Polyhalite: Potassium, Sulphur, Magnesium and Calcium for Efficient Balanced Plant Nutrition”. It was organized by the International Potash Institute (IPI) together with Chinese Agricultural University (CAU) and the Institute of Soil Science of Chinese Academy of Science (ISSAS). The National Agro-Tech Extension and Service Center (NATESC), China Inorganic Salts Industry Association (CISIA) and Yunnan Agricultural University were co-organizers of the event in Kunming, China, 6-8 November 2019. More than 300 professionals – including researchers, students, farmer advisors and fertilizer retailers, from China and other parts of the world – invested three days to learn, discuss and share.

Seeing and hearing

Senses of sight and hearing were put to good use, concentrating on the evidence presented from research into the benefits of balanced plant nutrition in China and other countries including Brazil, India, USA, Switzerland, Israel and UK. This evidence, from painstaking research and observations, is essential for inspiring and developing better fertilizer strategies in China and beyond.

From around the world, speakers stressed the facts that sulphur (S), magnesium (Mg) and calcium (Ca) nutrient deficiencies are increasingly becoming an important limiting factor in intensive crop production systems and their depletion in soils is a growing concern.

Philip White (The James Hutton Institute, UK) presented the role of Ca in plant nutrition, while Jiwan Palta (University of Wisconsin, USA) went deeper in illustrating the role of Ca for potato and its importance in skin quality. The crucial functions of S were presented by Surinder K. Bansal (Potash Research Institute of India). Magnesium’s role was explained by Chunjian Li (China Agricultural University).

An efficient solution to the need for S, Mg and Ca in agriculture is of course polyhalite (marketed by ICL as Polysulphate): a new multi-nutrient fertilizer with a prolonged nutrient release pattern that constantly delivers S, Mg, K, and Ca, reducing the risk of leaching. Different experiments presented during the symposium showed the positive effect of polyhalite on crop growth, yield and quality worldwide.

More than 300 professionals invested three days to learn, discuss and share.
A world of experience brought together

Listening to the speakers was a globe-trotting experience. Kang Ni (Tea Research Institute, China) presented work on tea quality following polyhalite application. Michael Castellano (Iowa State University, USA) summarized Polysulphate trials in corn and soybean in USA. Polysulphate fertilizer management was explained for potatoes in Inner Mongolia by Mingshou Fan (Inner Mongolia Agricultural University, Hohhot, China); for pastures in Brazil by Alberto Bernardi (Embrapa); for greenhouse tomatoes by Mollie Sacks (Israel Ministry of Agriculture, Extension Service), and for soybean in Brazil by Fabio Vale (IPI coordinator for Latin America).

An update on research with Polysulphate in a range of crops including pasture, coffee and groundnut in Vietnam was presented by Toan Tran Duc (Soils and Fertilizers Research Institute). Patricia Imas (IPI, Switzerland) presented polyhalite as a new potassium fertilizer with the benefit of three additional nutrients.
Strength in numbers: multinational evidence of benefits of Polysulphate

The conference heard examples from four continents of the benefits of Polysulphate:
  • From Brazil – IPI experiment in Tocantins state presented a 12.7% yield increase of soybean due to Polysulphate application as compared to potassium chloride. Another experiment in alfalfa showed the positive effect of Polysulphate on nutritive value for livestock: Polysulphate decreased lignin by 11%, while increased protein percentage by 4%.  
  • From China – an IPI experiment on potato showed 21% increase in yield with Polysulphate as compared with SOP in Inner Mongolia. In Guandong province, 16% more yield was obtained with Polysulphate application to wax gourd as compared with the farmers’ practice. Polysulphate was also shown to be an effective source of magnesium for pepper, showing a 19% increase in yield as compared with no Mg application.  
  • From India – Polysulphate enhanced lycopene and ascorbic acid contents in tomato by 31% and by 21% respectively, as compared with farmers’ practice. In onion, Polysulphate application increased yield by 38% while also increasing the quality as measured by enhanced protein content and higher TSS.  
  • From USA – corn trials showed that compared to other sulphate-based fertilizers, lab and field results suggest Polysulphate redresses sulphur deficiency in the first year and has residual effect.
Opening ceremony of the Symposium.
Pointing out the need for precision with potash

Potassium (K) requirements vary. Fast-growing fruits and vegetables have different needs to cereals or oil seeds. Several presentations in the symposium dealt with potassium’s role in crop production and the importance of using potash to achieve optimum crop productivity and sustainability.

From basic breeding and genetics for K-efficient rice, through to K issues in plant physiology, and the role of K in increasing plant resistance to diseases – all these and more were covered in different presentations. Sharing new knowledge and ideas is helping to evolve new strategies for promoting balanced fertilization.
Demonstrating Polysulphate application with a manual device during the field trip to vegetables and flowers tunnels.
A scented crop nourished with Polysulphate

There was also inspiration outside of the conference hall. The poster session provided a wide variety of stimulating snapshots of research underway.

The sight and fragrance of flowers, on one of the field visits, was another sensory opportunity. The host farmers welcoming Symposium visitors in one village showed how they grow sweet-scented and beautiful Hoary Stocks for the regional cut flower market. In their polytunnels, they happily demonstrated their novel portable spinner to apply Polysulphate and explained that with Polysulphate the flowers are more colorful and the plants stronger and higher. Other tunnels with leafy vegetables showed that Polysulphate application results in better root development.
A taste of things to come

During the final session, there was a call for high quality ‘green’ agriculture. This presented the chance to show the role of polyhalite and potash for each of the steps to achieve that goal:
  • To transform from production-oriented to quality-oriented agriculture – using polyhalite, supplying 4 quality-enhancing nutrients is evidently beneficial.
  • To achieve high nitrogen use efficiency and less environmental damage – by applying K, S, Mg and Ca, farmers ensure better uptake of N, improved utilization of precious irrigation water, more robust growth and yield, and increased profits.
  • To increase sustainability – efficient and balanced nutrient management is closely related with the 17 Sustainable Development Goals set by the United Nations.
  • To benefit the whole food supply chain – balanced use of fertilizers is key to serve food companies, supermarkets and consumers with nutritional and quality food.
  • To use precision to feed the world – evidence and data, big data and metadata analysis will lead to fertilizer optimization and site-specific fertilization recommendations to help farmers maximize crop yields in the most efficient and cost-effective way.

We hope this Missive gives you a taste of Kunming Symposium: a remarkable international event hosted in China providing inspiration and information in a memorable way.

The presentations from the event are available on the Presentations from the 13th IPI-CAU-ISSAS International Symposium page.
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Mined in the UK, ICL is the first – and only - producer in the world to mine polyhalite, marketed as Polysulphate