By targeting three major soil types prevalent in different regions of China, researchers have revolutionized farming methods and boosted crop yields.

Overcoming high salt concentrations in saline-alkali soils (pictured) has been a priority for Institute of Agricultural Resources and Regional Planning.Credit: Moritz Wolf/imageBROKER/Getty

The range of climates and environments across China pose distinct challenges for farming systems. Different agricultural approaches are needed for three major soil types found in the country: saline soils in the north, black soils in the northeast, and red and yellow soils in the south.

Over six decades, the Institute of Agricultural Resources and Regional Planning (IARRP) at the Chinese Academy of Agricultural Sciences in Beijing has been developing strategies to address this challenge through agricultural research and innovation."Our mission is to harness cutting-edge technologies to enhance traditional farming practices, promoting both productivity and sustainability," says Wenbin Wu, agricultural scientist and director of IARRP.

IARRP adopted a core research strategy known as the '3+3+1' system: three soil types, three regional research stations and one digital agriculture system. Tailored to the characteristics of each soil type, IARRP's research focuses on enhancing soil quality, increasing crop yields, and fostering sustainable agricultural practices.

Blocking salt

Saline-alkali soils, which cover a vast and widely distributed area of China, are crucial resources for agriculture. But, these soils contain high concentrations of soluble salts, which can stunt plant growth by limiting their ability to absorb water.

Yuyi Li, a soil scientist and chief researcher at IARRP, developed a 'stratification' technique to reduce salt concentrations. The technique involves embedding organic materials, such as straw, at various depths in the soil to obstruct the capillary movement of saline water from below.

At a depth of about 40 centimetres, a dense layer of straw acts as a barrier to prevent salt from rising to the root zone, protecting crops from salt stress1. Furthermore, as the straw decomposes, it stimulates microbial activity in the soil, leading to improved soil health and increased nutrient availability.

This innovative approach has yielded great results, say the scientists. Field studies in the Yellow River Delta and the arid region of northwest China, where salinity levels historically hindered agriculture, show that the technique has helped revitalize vast tracts of once unproductive land and improved the overall soil structure and fertility, resulting in 10-20% increases in crop yields2.

Crucial nutrient

A prevalent problem in southern tropical and subtropical regions with red and yellow soils is phosphorus deficiency. Red soils are characterized by a high prevalence of iron minerals which can oxidize and cause yellowing.

Phosphorus is an essential nutrient for plant growth and development. When plants lack sufficient phosphorus, they can experience stunted growth, underdeveloped roots and increased susceptibility to stress — which in crops leads to decreased yields. Fertilizers containing inorganic orthophosphate are often applied to soils to remedy the deficiency. As a type of phosphorus compound, inorganic orthophosphate can be easily absorbed by plant roots and utilized for various cellular processes.

An 'orthophosphate visualization' technique allows scientists to study the distribution of nutrients within rice plant cells.

"While phosphorus fertilizer boosts crop yields, its overuse can negatively impact the environment," says Wenyuan Ruan, an IARRP researcher who specializes in soil-plant interactions.

Ruan and his colleagues at IARRP have developed an 'orthophosphate visualization' technique3 to dye and tag orthophosphate. Using dye, researchers can observe the concentration of orthophosphate within plant cells through high-resolution imaging.

The technique allows the scientists to directly observe how orthophosphate is distributed and utilized within the cells of plants. It enables precise fertilizer application tailored to the exact needs of crops.

"This technique gives us the unprecedented ability to directly monitor the orthophosphate status of each cell, enabling the precise design of phosphorus use strategies at the cellular level to improve crop phosphorus efficiency," Ruan explains.

Digital system

The technique also opens the door to the development of genetically engineered crops that can thrive in phosphorus-deficient soils, say the researchers. This is because it could help identify genes linked to phosphorus uptake and metabolism, explains Ruan. This would be especially beneficial for crops such as rice and wheat, because they rely heavily on phosphorus for growth.

Under the guidance of Wu, the IARRP has pioneered a transformation in agricultural practices with its 'Digital Tillage System' (DTS).

An image from the Institute of Agricultural Resources and Regional Planning's Digital Tillage System helps with precise planning.

Under this system, Internet of Things (IoT) devices, such as sensors, collect vital data on soil conditions, while drones equipped with high-resolution cameras monitor crop health and manage the application or resources, such as fertilizer, with precision. Through data integration, the system provides a comprehensive overview of the agricultural conditions in a specific region, guiding agricultural planning.

A prominent example is its application in Tibet, where the rugged terrain makes it difficult to collect data using traditional methods. To address this, a 'crowdsourcing' approach to data collection was implemented, engaging advanced equipment and local residents through easily accessible platforms and tools. "It shows how technology and community engagement can be integrated to improve agricultural planning in challenging regions," Wu says.

With the DTS, IARRP has also significantly improved China's national soil surveys. The technological advancements have helped collect more precise and actionable data for the ongoing third national soil survey, compared to the previous survey, Wu says.

"The DTS enhances policy-making and targeted agricultural interventions, setting new standards in soil research and management, ensuring that interventions are targeted and effective," says Wu.

Looking ahead, IARRP scientists have their sights set on climate resilience and sustainable agriculture to address future agricultural challenges. Wu says that the institute's research and technologies can provide sustainable solutions to global agricultural challenges acrossthe world.

"As we advance, our goal is to preserve and harness arable lands, adapting to changing climate conditions while ensuring global food security," Wu says.

Nature Research Custom : https://www.nature.com/articles/d42473-024-00186-0