A splendid array of straw-made miniatures of classic ancient buildings adorn Xu Jian's home. They range from the Yellow Crane Tower in Central China's Hubei province to Forbidden City's turrets in Beijing. They are all full of details and delicately crafted, tied and arranged by Xu's ingenious hands from countless sorghum straws.

"All the pillars, beams, eaves, brackets, doors and windows and everything else are crafted from sorghum stalks," Xu points to the Yellow Crane Tower that is 1 meter high at his base in Yongqing county, Langfang city, North China's Hebei province.

This particular piece was made out of hundreds of thousands of sorghum stalks and took him two years to complete without the use of any nails or glue.

"It relies entirely on interlocking, tenon-and-mortise construction," the man in his 30s explains.

The craft involves carving grooves into the sorghum stalks, before multiple stalks are then locked together through those identically sized grooves, a technique referred to as tying, Xu says, adding that the art form combines elements of geometry, physics, architecture and mechanics.

"The framework of all the carved and tied straw works is composed of six interlocked sorghum stalks. Starting from the bottom and working from the inside out, the interlocked stalks are layered, much like building a house," Xu explains.

He emphasizes that the sorghum straw art requires a great deal of patience, especially for works depicting ancient architecture.

"The extensive tenon-and-mortise structures all need to be manually grooved and fitted, taking several months or even one to two years to complete," he says.

Additionally, all the beams and columns are straightened after being individually heated over an alcohol lamp.

"It's the only way that every door and window installed can open and close properly, ensuring a neat final work," Xu says.

The sorghum straw art adheres to strict standards from raw material selection to production.

Xu has cultivated over 3 mu (2,000 square meters) of sorghum in his farmland, and selects those of the highest quality to create straw works when they mature.

"The sorghum stalks range from the finest at 1.8 millimeters to the thickest at 12 mm. Almost every piece involves hundreds of crafting steps," Xu says.

He doesn't waste the leftover scraps either, as he turns them into windmills.

"In the eyes of many, sorghum straw is merely an agricultural waste, but through the creativity of craftsmen, it can be turned into a treasure, being transformed into exquisite works of art," Xu says.

Xu has a long scar on his right thumb due to an accident, as if a testament to the challenges of the craft.

Cultivation of interest

Under the influence of his father Xu Yanfeng, who was named a national inheritor of the art in 2009, Xu Jian got his hands on sorghum straws in childhood.

He still vividly remembers how his father would follow a film featuring scenes of Tian'anmen Square when it was circulated among neighboring villages and then note down all the details before creating a delicate miniature of it for over three years.

"The city wall, city tower, auxiliary building, Jinshui Bridge and ornamental columns were all complete, and every door and window could open and close freely," he recalls.

The work was then sent to Japan for exhibition and collected by a local museum. Ever since, many of his father's works made their way to exhibitions at home and abroad.

In order to render sorghum stalks sturdier and a more uniform color, Xu Yanfeng independently came up with a hybrid that is more robust and flexible than the garden-variety species after two years of experimentation.

Under his father's instructions, Xu Jian managed to pull off small trinkets, such as cricket cages and distinctive Chinese knots in childhood.

He became committed to the art after he reached 19, getting into the depth of the related techniques.

"My father urged me to keep in mind traditional Chinese architectural skills and the history of traditional building protections, and to apply them to my own sorghum straw artworks," he says.

Through hands-on guidance from his father, Xu Jian's skills became increasingly proficient. He mastered the whole process, from sorghum seed cultivation, harvesting, sorting and measuring to designing, drawing, grooving, fitting and assembling the main structure.

"Sorghum straw carving and tying are unique skills with which you can construct a three-dimensional structure based on a photography of a building," Xu Jian says.

This is also the most challenging aspect of the art, he says, adding that one needs to meticulously plan each section of a sorghum straw work in the mind, then translate it into drawings before finally constructing it.

"The creative process is often mentally taxing. When I have a clear idea, I have to execute it in one go; otherwise, I'll need to rethink, which ends up taking more time," Xu Jian says.

Over the years, many have approached Xu Jian's family to learn the art, but only a few stay the course, due to the time-consuming nature of the art and labor intensity.

"For instance, the details are the key, and you need to use a caliper to measure each sorghum stalk to ensure they meet the standard, while controlling force in the production process, so every cut is just right, not too shallow nor too deep," he says.

"One also must endure loneliness during the practice."

Innovation and promotion

While inheriting the craftsmanship from his father, Xu Jian has produced his own innovative works.

He has ingeniously delivered conjoined pavilions to mean lasting friendships that enjoy brisk sales online among young people.

The Winter Olympics-themed five-ring windmills he made out of sorghum straws drew a great deal of attention at a temple fair in Beijing during this year's Spring Festival.

To date, Xu Jian's works have been exhibited in over 40 provincial and national-level exhibitions, earning numerous gold awards, including one from China Huangshan intangible cultural heritage craftsmanship exhibition in Anhui province in 2012.

To promote the art, Xu Jian joined hands with the School of Civil Engineering, Hebei University of Science and Technology, in 2013, and founded a sorghum straw carving and tying base where the art has been integrated with architectural courses to enhance students' thinking and practical skills.

From 2016, Xu Jian has also made his way to primary and middle schools in Langfang, as well as neighboring Beijing and Tianjin, to promote the art.

He explains aesthetic structures of ancient classical architecture, introduces the history of the sorghum art and teaches students how to make small art items.

"They all show great interest, and some students, after a semester of courses, can already construct simple buildings with a proper structure through the straw techniques," Xu Jian says.

Song Ruofei from a primary school in Yongqing county has been fascinated by the art since Xu Jian gave a class in April. She used the straws and fashioned a Luban lock, an educational toy first created by well-known Chinese carpenter Lu Ban 2,000 years ago. "I can't believe I could pull it off, making such a delicate work," she recalls.

She says she will spend more spare time practicing the art in the future.

Xu Jian has also created short videos online to demonstrate the sorghum straw techniques. He and his sister have established an intangible cultural heritage workshop in their hometown, where they organize training sessions annually for rural women to increase income.

Through nearly two decades of engagement in the art, Xu Jian has been invited to many national and provincial exhibitions to showcase his work.

"The primary mission of an inheritor of intangible cultural heritage is to preserve, but innovation is also crucial," Xu Jian says.

He plans to incorporate more modern elements into the sorghum straw art, such as creating works depicting Shenzhou spacecraft and China's aircraft carriers.