Beijing corn to be trial-planted on 10 million mu of farmland next year

Corn, with a planting area of 550 million mu, is one of China's most important crops. For a long time, corn sowing and harvesting have relied entirely on manual labor, and only American corn varieties could be fully mechanically sown. Next year, 10 million mu of farmland in China will be fully mechanically planted with “Beijing corn”, which is China's first domestically bred corn variety to achieve full mechanization from sowing to harvesting.

Yesterday, a reporter learned from the Rural Center of the Municipal Science and Technology Commission that two new corn varieties, Lianchuang 808 and Yufeng 303, bred by the Beijing enterprise Lianchuang Seed Industry, have passed national crop variety approval and been publicly announced. The two new corn varieties independently developed in Beijing can achieve fully mechanized production. Fully mechanized corn production means mechanizing the entire process of corn from sowing, management, harvesting, grain drying and grain circulation.

At present, the sowing and harvesting of domestic corn varieties mainly rely on manual labor. Whenever corn matures, a large amount of manpower and material resources must be drawn upon to race against time for the harvest, after which comes breaking off the cobs, transport, sun-drying, threshing, drying the kernels, collecting the kernels, cleaning, selling, storage and other steps.

“Single-seed sowing and direct grain harvesting are the two major difficulties in fully mechanized corn production.” Wang Yibo, chief scientist of Lianchuang Seed Industry, introduced that corn varieties developed through hybridization and transgenic breeding have achieved the presentation of hard endosperm in corn——the starch and other nutrients inside the corn kernel are not easily pulverized and are protected by a hard film. In this way, it is possible to effectively avoid seeds pulverizing during sowing and failing to germinate; it is also possible to thresh directly at harvest without worrying about the corn kernels being crushed.

Manual sowing plants three seeds per hole, while mechanical sowing plants one seed per hole to ensure a sufficient germination rate. For seeds alone, mechanical sowing can save farmers 30% of costs per mu. In addition, mechanical sowing speed is several times to ten times that of manual labor. “The daily wage for manual labor is 150 yuan, and manual sowing covers only one mu per day. If more than one seedling grows in a hole, the excess seedlings must also be removed, which takes a lot of effort.” a scientist at Lianchuang Seed Industry said. Moreover, mechanical corn harvesting can finish 100 mu per day, the harvesting cost per mu is only half that of manual labor, and steps such as threshing can also be completed at the same time.

Compared with sowing, directly harvesting grain has always been the hardest “difficulty” to overcome. In addition to factors such as the grain moisture being far higher than that of wheat and the kernels being easily broken, how to quickly and cleanly strip off the husk leaves outside the corn cob is also a challenge. For traditional corn varieties, the husk leaves tightly wrap the outside of the cob. The outermost layer of husk leaves is highly fibrous and can easily jam the rotating shaft of the thresher; the inner husk leaves have high moisture, are not easy to peel off, and can easily stain the corn kernels with juice.

“The new corn variety can naturally loosen its husk leaves in the last few days of maturity, making them very easy to strip off completely.” Wang Yibo said, “More interestingly, we have made the husk leaves of the corn cob mature from the inside outward, so the inner husk leaves dry earlier than the outer layer.”

At present, when the new variety of corn at the demonstration base is harvested and threshed, the husk-leaf “stripping rate” has reached 90% to 95%, surpassing American corn varieties.

At the same time, because of the protection of the hard endosperm, the corn kernels are also not easily broken. Harvesting video shows that although the corn field is still bright green, the mechanically harvested and threshed corn is golden yellow with intact kernels. “Under this harvesting condition, the moisture content of the corn kernels is as high as 30%, more than twice the moisture content of mature wheat.” Wang Yibo told the reporter that farmers can begin harvesting corn four or five days earlier and bring it to market, “and the price per jin can be 5 fen higher.”

In addition, the domestic corn varieties also have better lodging resistance, density tolerance and disease resistance than American corn, and the average yield per mu can be increased by 8% to 10%.

The entry of the “Beijing corn” variety into the market has broken the monopoly of foreign corn varieties in the field of mechanized production. “Next year our corn varieties will be planted on 10 million mu in regions such as Northeast China and North China, the Yellow River-Huai River-Hai River area, the Northwest and the Southwest.” Wang Yibo said that according to the improved seed promotion plan, the planting scale will reach 40 million mu in 2018.