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 is dense planting combined with shallow-buried drip irrigation and integrated water-fertilizer management 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 show that under the shallow-buried drip irrigation split precise fertilization model, multiple varieties such as "Liaodan 1209," "Jianfeng 102," and "Liaodan 336" all demonstrated significant yield advantages, with average yields per mu exceeding 2,200 jin, 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-class grain procurement standard.
"Under conditions of high temperature and low rainfall, adopting shallow-buried drip irrigation to achieve yield increases is very necessary. Over the entire growth period, corn is given 8 rounds of drip irrigation and 6 rounds of supplemental fertilization, which is equivalent to feeding a 'nutritious meal' according to the corn's fertilizer and water requirements, greatly improving water and fertilizer use efficiency and reducing overall water and fertilizer input costs," introduced Zhang Shuping, associate researcher at the Corn Research Institute of the Provincial Academy of Agricultural Sciences.
"Sixty percent of the land has achieved 'ton-grain fields,' and the best-performing plots even saw yield increases reaching a thousand jin per mu — something unimaginable in the past." Local large-scale grain grower Sun Jigang, under the guidance of experts, has adopted dense planting combined with shallow-buried drip irrigation and integrated water-fertilizer management technology for three consecutive years, and all 15,000 mu of his corn fields have achieved yield increases.
At present, in the province's projects implementing corn yield increases, corn is planted at about 6,000 plants per mu, a significant increase from the previous 4,000 to 4,500 plants, but still a considerable gap compared with the approximately 8,000 plants per mu in Xinjiang, where temperature and light resources and water and fertilizer conditions are better.
"Corn likes ventilation and light, and high-density planting is a challenge to corn's natural attributes. The key issue is that there are still not many density-tolerant varieties," Zhang Shuping explained, adding that adopting wide-narrow row planting only somewhat alleviates the contradiction.
In response to prominent problems in Liaoning such as frequent extreme weather, low corn planting density, lack of density-tolerant varieties, and low water and 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 focused on the core bottlenecks limiting corn yield increases in Liaoning. At the beginning of this year, the team arranged and carried out research and demonstrations of more than ten core technologies, including screening high-yield, density-tolerant, and disease-resistant varieties across different ecological zones, and tapping high-yield density potential.
Zhang Yang, director of the Corn Research Institute of the Provincial Academy of Agricultural Sciences, stated that the practice of increasing corn yields in the province shows that a 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 focus on breeding density-tolerant 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 yields reach even higher levels.