Year-2021 was the end of the first 5-year period of the International Magnesium Institute (IMI) establishment and the beginning of the second 5-year period of cooperation. In the past 5 years, IMI has paid close attention to the plant magnesium (Mg) nutrition, application effect of Mg fertilizer, and focused on Mg effects in the integrated management of NPK fertilizers in China's agricultural production. It has drawn the 'IMI's attention to the reducing use of fertilizers while increasing the quality of cereal crops, fruits, vegetables, and other horticultural crops. The planting area of the horticultural crops has increased rapidly since the few decades, while fertilizer input per unit area is still very high. However, effective nutrient management practices are still lacking and need great attention to reduce the input of fertilizers while improving the quality of horticultural products.

China has achieved food self-sufficiency relying on its own. It has been producing enough food by minimizing fertilizer use during food production. Meanwhile, it has also been the key focus to improve the quality of agricultural products and fertilizer use efficiency. In the past five years of IMI, significant progress has been made in the basic research and promotion of reducing the use of NPK fertilizers and Mg supplementation to increase the fertilizers use efficiency and quality of agricultural products and their application in practice. Hence, most of the work summary related to the aforementioned has been discussed in detail in this annual report. In the second phase of the 5-year period cooperation, IMI will continue to focus on improving the quality of agricultural products, fertilizer use efficiency, and utilization of Mg fertilizer in agricultural production. It has also been encouraged to produce green and intelligent fertilizers to promote green agriculture development in China.

In 2021, the global coronavirus continued to rage and affected everyone's work and life under such global epidemic circumstances. However, the teachers and graduate students of IMI and NMN (National Magnesium Network) extensively carried out academic exchanges. They spread the Mg knowledge and scientific use of Mg fertilizers through online tools and other social media platforms. Together with K+S, IMI publicized the importance and practical application of Mg fertilizers to entrepreneurs and farmers who worked closely in agriculture production and promotion, and it ensured the progress of the scheduled planned work.

The monograph "Magnesium Nutrition and Its Effects on Crop Yield and Quality" was published in 2021. It brought together the research results of IMI and NMN members over the past years. It systematically introduced the latest research progress made in plant Mg nutrition, the requirement of Mg for various crops, and the effect of Mg fertilizer on crop yield and quality improvement. The status of the exchangeable Mg concentration in soils across the country has been shown. The photos of typical Mg deficiency symptoms in fruit trees, vegetables, and other crops collected in the field could help to understand better the Mg importance and its deficiency phenomenon in the production. It could play a critical role in the promotion and application of Mg fertilizer.

Over the past 5 years, IMI and NMN have trained a number of young researchers to become experts in different crop species to solve the problems in the production of different regions. They have gradually developed their expertise and carried out scientific research independently. They also have shown their responsibilities in guiding graduate students, solving the production problems, and using the research results for promotion and application. They are expected to be the leading force in China's agricultural production at present and future, and making more outstanding contributions to the green development of agriculture in China and worldwide.