With the arrival of spring rain, all things come to life. Rain Water, the second term of the Chinese 24 Solar Terms, is known as the time for plowing. Farmers in most places of China begin to do their spring farmwork. Winter crops gradually enter the critical period of turning green from south to north, leading to a rapid increase in nutrient demand.

"What kinds of fertilizers are mostly wanted as wheat will soon need additional fertilizers?" said Xu Yanyun, a farmer from Guantao couty of North China's Hebei province, to the owner of an agricultural supplies store.

As the solar term of Rain Water arrives, farmers in many regions across the country have gradually entered the busy time of spring farmwork. Fertilizers are major agricultural supplies that provide crops with mineral nutrients and are responsible for about 50 percent of crop yield increase.

Statistics show that in 2024, the fertilizer utilization rates for China's three major grain crops—rice, wheat, and corn—reached 42.6 percent, an increase of 1.3 percentage points from 2022. Fertilizer utilization rate reflects the effectiveness of fertilizer utilization in agricultural production. The improvement of scientific fertilization practices has become a window of the shift in agricultural development methods.

How will farmers bring down their fertilizers usage?

Appropriate amount of fertilizers crucial for crop growth: from customized fertilization services to AI assistance

Xu owns 11 mu of wheat farmland. In the past ,he often blindly spread fertilizers and followed the views of others. In recent years, he has realized that crops also have "feast and famine." Improper fertilization will not only increase costs but also negatively affects yield and soil fertility.

"It is suitable to use compound fertilizers since wheat seedlings have high nutrient requirements during the greening period," explained Zhang Junfen, manager of the agricultural supplies store. Although compound fertilizers have more diverse nutrients and higher efficiency, yet it is essential for farmers to select compound fertilizers with appropriate nutrient ratios in accordance with the application of base fertilizers.

Over the past years, farmers have attached more importance to the relations between investment and output and to the concept of ecological efficiency and become highly savvy about fertilization practices. Currently, there are over 30 types of fertilizer products in China, which cover essential mineral nutrients and beneficial elements needed for various crops in solid, liquid, and other forms, and meet the needs of agricultural production.

Meanwhile, technological services have been easily reachable by farmers in parallel with the fast circulation of fertilizers.

Soil testing and formulated fertilization is an important foundation for improving the utilization rate of fertilizers. "We have established a three-level technical service team to visit villages and households to guide farmers in the scientific use of fertilizers," said Wang Shuai, manager of the Channel and Collaborative Business Department of Sinochem Fertilizer Co., Ltd. In response to the differences in soil organic matter and pH in different regions, the company has provided soil sampling and testing services, analyzed and determined the optimal ratio of nitrogen, phosphorus and potassium, and come up with special compound fertilizers for production and operation entities. Since the beginning of this year, it has undertaken more than 480 technical training sessions for spring farmwork and over 300 soil testing and fertilizer formulation.

Supported by agricultural technology promotion departments at all levels, the annual promotion area of the soil testing and formulated fertilization technology nationwide has exceeded 2.3 billion mu. Among them, the application coverage rate of relevant technology on the three major grain crops has surpassed 95 percent. All localities have focused on the five major links of "testing, formulating, producing, supplying and applying", strengthened the connection between agriculture and enterprises, and promoted the implementation of formulated fertilizers. Right now, there are more than 17,000 social service organizations for scientific fertilization and over 2,000 intelligent fertilizer formulation service outlets distributed on the farmland, providing farmers with an "one-stop" scientific fertilization service that includes intelligent diagnosis, digital fertilizer formulation and mechanized application.

In addition to social service organizations, farmers can also seek the help of artificial intelligence for fertilization. By opening the "NE Nutrient Expert" intelligent scientific fertilization expert recommendation system on their mobile phones, farmers will find a simulated farmland marked with geographical information such as location, temperature, humidity and wind direction on the screen. A personalized fertilization plan will be generated through the algorithm model for reference when users input plot information such as crop type, plot location, soil texture, and soil fertility of the plot.

"The intelligent recommended fertilization technology, which is based on a large amount of soil testing and field experiment data, can provide a reference for precise fertilization," said He Ping, researcher of the Institute of Agricultural Resources and Regional Planning of the Chinese Academy of Agricultural Sciences (CAAS). He is also the chief scientist of a national key research and development program titled "Precise Regulation of Crop Nutrients and Reduction Substitution Technologies in Major Grain-Production Areas".

The "NE Nutrient Expert" system has been connected with some provincial-level agricultural service platforms to provide farmers with real-time fertilization recommendations. It is anticipated that the application of this technology will reduce the amount of fertilizers by 10 to 30 percent and the investment per mu by 50 to 100 yuan. Meanwhile, the yield has steadily increased (with an increase of corn from five to eight percent), and the fertilizer utilization rate has grown by 10 percent.

Specialized fertilization: continuous adoption of new products, technologies and equipment

"Fertilizing a large area is not as good as fertilizing in a line." The adoption of the side-deep fertilization technology for rice will increase the utilization rate of nitrogen fertilizers nationwide by 3.7 percentage points.

In the past, with the conventional fertilization method, fertilizers were spread on soil surface after the rice seedlings were transplanted. They were easily blown away by the wind or washed away by water, resulting in a low utilization rate. "Now with the new technology, the fertilizer is 'fed' to the roots simultaneously with the rice transplantation. It won't be blown away by the wind or washed away by water, and the nutrients can be absorbed more effectively," said Du Xinming, head of Fugen Agricultural Machinery Service Professional Cooperative in Yixing city of East China's Jiangsu province. From the transplantation to rice harvest, the number of fertilization has been significantly reduced, from the conventional 4 to 5 times to 1 to 3 times. There is no need to apply the base fertilizer before soil preparation and rice transplantation, and the average nitrogen fertilizer usage per mu is reduced by more than 15 percent.

However, compared with conventional fertilization technology, side-deep fertilization requires supportive side-deep fertilization devices, special fertilizers, etc. The price of each ton of slow and controlled-released fertilizer is about 1,000 to 1,500 yuan higher than that of ordinary formulated fertilizers.

How are farmers willing to actively adopt this technology? Qiu Meihua, a senior agronomist at the Cultivated Land Quality and Agricultural Environmental Protection Station in Jiangsu, introduced that since 2021, the province has used financial fund from the central government to provide a subsidy of 5,000 yuan for each set of rice side-deep fertilization devices purchased by farmers. It has also provided about 75 million yuan of special provincial financial funds every year for the promotion of relevant technologies intended to reduce fertilizer utilization and increase operational efficiency. Last year, the promotion area of rice side-deep fertilization in the province reached 1.14 million mu, doubling that of 2020.

Slow and controlled-released fertilizers, water-soluble fertilizers, microbial fertilizers, soil testing and formulated fertilization, diagnostic fertilization, variable-rate fertilization, combined seeding and fertilizing machines, side-deep fertilization machines, fertilizer-spraying drones... From new products and technologies to new agricultural machinery, fertilizer field continues to introduce new items. Wang introduced that in response to the saline-alkali land in the northwest China and other regions, this year Sinochem Fertilizer has worked together with China Agricultural University to successfully develop a beneficial microbial technology for targeted regulation of saline-alkali land that can regulate the soil pH, reduce salinity and improve the soil structure. On this basis, a new type of organic water-soluble fertilizer has been developed to help improve the quality of cultivated land.

The organic combination of various technical models has led to a progressive increase in fertilizer utilization efficiency. In Inner Mongolia autonomous region, the technical model of "soil testing and formulated fertilization + combined seeding and fertilizing + integration of drip irrigation and fertilization under the film" has not only ensured uniform drip irrigation and fertilization but also saved water and fertilizers and reduced labor costs. In Henan province, during the heading and flowering to filling stage of wheat, drones have been used for spraying fertilizers on nutritional diagnosis, achieving precise quantification of fertilizer application. In Anhui province, with the method of combined seeding and fertilizing, soybeans have been inoculated with rhizobium inoculant, which significantly enhances the nitrogen fixation ability.

"It is also very important to master the corresponding knowledge and skills when farmers make good use of these integrated and supportive technical models," said He. On the one hand, it is necessary to increase investment in research and development, deepen cooperation between scientific research institutions and enterprises, and optimize the adaptability between new fertilizers and intelligent application technologies. On the other hand, it is also necessary to strengthen training services, demonstration and promotion to ensure that the technical achievements can bring the greatest benefits.

Diversified fertilizer substitution: organic and fertilizers boast different advantages

In addition to focusing on fertilizers themselves, the realization of multiple substitution through such methods as planting soil-improving crops like green manure and returning manure to the fields nearby is also an important measure to improve the utilization rate of fertilizer.

In Yuanjiang city of Hunan province, the wild fields in the early spring are covered with a soft layer of new green. This is milk vetch, a green manure crop promoted by local government. The city has provided the seeds for free and the planting area has reached nearly 200,000 mu at its peak.

"The milk vetch is growing vigorously this year and can be plowed back into the field in March," said Zhang Weiying, head of Baomin Rice Professional Cooperative in Yuanjiang. Milk vetch belongs to the legume family, and its root system has a strong nitrogen fixation ability. The humus formed after it is plowed and buried can increase the active organic matter in the soil. The rotation of "green manure - rice" can reduce the application of five kilograms of urea and five kilograms of superphosphate per mu, and scale down the use of pesticides once a year. Moreover, farmers can harvest 45 kilograms of milk vetch seeds, and the yield of the subsequent rice crop is expected to increase by about 5 percent, with an average cost reduction and efficiency increase of about 100 yuan per mu.

In the organic fertilizer fermentation workshop of Qingfeng Biotechnology Co., Ltd. in Guangtao, workers are busy turning and tossing the organic fertilizer to promote the decrease of moisture and uniform fermentation. "During this period, our six production lines are operating at full capacity, producing more than 1,000 tons of organic fertilizer every day. It products have been sold locally and beyond such as Shandong and Henan," said Wu Qingfeng, manger of the company. In Guangtao, several centralized treatment centers for livestock and poultry manure have been built in accordance with the planting and breeding businesses, and the resource utilization rate of livestock and poultry manure in the whole county has exceeded 90 percent.

Many people are wondering whether organic fertilizers can replace chemical fertilizers?

"Organic fertilizers and chemical fertilizers each have their own advantages," said Du Sen, chief expert of the National Agro-tech Extension and Service Center. Organic fertilizers play a unique role in increasing soil organic matter, improving the granular structure, and enhancing soil fertility. However, under the current circumstances of high-intensity agricultural planting and high-yield requirements, the mere dependence on soil nutrient supply or utilization of organic fertilizers cannot continuously meet the needs of high-yield and high-quality crops in terms of quantity or intensity. Many field experiments have proven that without the application of chemical fertilizers, the crop yield will decrease by more than half within three years.

Using chemical fertilizers scientifically and making the best use of them is of great significance for ensuring food security. In recent years, the Ministry of Agriculture and Rural Affairs has introduced a series of major actions such as the zero growth of chemical fertilizer usage, the reduction of chemical fertilizer utilization, and the pilot projects of green planting and breeding circular agriculture, continuously promoting the reduction of chemical fertilizer utilization and the improvement of its efficiency. According to the data from the National Bureau of Statistics, the amount of chemical fertilizers applied in agriculture nationwide in 2023 was 50.2174 million tons, down 16.6 percent from the year 2015. It has been on decline for eight consecutive years.

According to the Planting Management Department of the Ministry of Agriculture and Rural Affairs, the country will focus on the improvement of a new round of 50-billion-kilogram grain production capacity. More specifically, the ministry will strengthen policy support for improving efficiency through scientific fertilization, and do a good job in basic tasks such as crop nutrition diagnosis, farmers' fertilization surveys, and field experiments.

Additionally, It will support social service organizations in providing services for manure collection, treatment, and returning to the fields, and establish a more stable interest linkage mechanism for the planting-breeding cycle.