On the sandy loam soil of Zhangwu County, how can corn achieve an average yield of more than 2,200 jin per mu? The answer lies in dense planting combined with shallow-buried drip irrigation and water-fertilizer integration technology.
Recently, the Provincial Academy of Agricultural Sciences organized a yield measurement at a corn high-yield technology demonstration base, revealing on site the "code" for stable corn yield increases.
The yield measurement results that day showed that under the shallow-buried drip irrigation split precision fertilization model, multiple varieties including Liaodan 1209, Jianfeng 102, Liaodan 336, and Liaodan 225 all demonstrated significant yield advantages, with average yields per mu exceeding 2,200 jin, representing an increase of more than 20% compared with surrounding non-irrigated areas. Moreover, the average test weight of corn kernels in the project area exceeded 720 grams per liter, reaching the first-grade grain purchasing standard.
"Under conditions of high temperature and low rainfall, adopting shallow-buried drip irrigation to achieve yield improvement is extremely necessary. The entire corn growth period involves 8 water applications and 6 fertilizer supplements, which is equivalent to feeding a 'nutritious meal' according to the corn's fertilizer and water requirements, greatly improving water and fertilizer use efficiency while also reducing overall water and fertilizer input costs," introduced Zhang Shuping, associate researcher at the Corn Research Institute of the Provincial Academy of Agricultural Sciences.
Local large-scale grain grower Sun Jigang shared his own experience, stating that under the guidance of corn experts, he has adopted dense planting and shallow-buried drip irrigation water-fertilizer integration technology for three consecutive years, and all 15,000 mu of corn fields have achieved yield increases compared with the past. "Sixty percent of the land has achieved 'ton-grain fields,' and the best-performing plots even saw yield increases of up to a thousand jin per mu, which was unimaginable in Zhangwu in the past."
Experts observed the corn high-yield technology demonstration base. At present, in the province's corn yield improvement project, corn planting density is about 6,000 plants per mu, a significant increase from the previous 4,000 to 4,500 plants, but there is still a considerable gap compared with the approximately 8,000 plants in Xinjiang, where temperature and light resources and water-fertilizer conditions are better.
"Corn likes ventilation and light penetration. High-density planting is essentially a challenge to corn's natural attributes, and the key issue is that there are still not many dense-planting-tolerant varieties," Zhang Shuping explained, adding that adopting wide-narrow row planting only partially alleviates the contradiction.
In response to prominent problems in Liaoning such as frequent extreme weather, low corn planting density, lack of dense-planting-tolerant varieties, and low water-fertilizer use efficiency, the Shenyang Comprehensive Experimental Station of the National Corn Industry Technology System and the Liaoning Corn Innovation Team have continued to carry out technical research focusing on the core bottleneck of corn yield improvement in Liaoning. At the beginning of this year, the team arranged and carried out screening of high-yield, dense-planting-tolerant, and disease-resistant varieties in different ecological zones, as well as research and demonstration of more than ten core technologies including creation of high-yield density potential exploitation.
Zhang Yang, director of the Corn Research Institute of the Provincial Academy of Agricultural Sciences, stated that the practice of corn yield improvement in the province shows that the technical system centered on dense planting and precise regulation can not only achieve substantial yield increases in normal years but also demonstrate significant stress resistance and stable yield capacity under extreme climate conditions. In the future, efforts will continue to be devoted to breeding dense-planting varieties with good stalk-standing ability, good plant architecture, moderate plant height, fast late-stage dehydration, and high temperature and light utilization efficiency, helping corn yield per mu reach a higher level.