Forage maize varieties are world-leading, so why are they hard to promote?
This year's Central Document No. 1 pointed out that it is necessary to accelerate the development of the grass-livestock industry, support the planting of forage crops such as silage maize and alfalfa, carry out pilot projects for converting grain to feed and combining planting with breeding, and promote the coordinated development of the three-way planting structure of grain, cash crops and forage.
Silage maize, converting grain to feed, combining planting with breeding——some maize seed companies sensitive to policy have keenly noticed the key words in Document No. 1.
At present, the vast majority of maize in China is harvested only for grain, while the stalks are directly crushed and incorporated into the soil. In fact, about 75% of maize used as grain ultimately ends up being used as feed. If part of ordinary maize could be changed to silage maize, with stalks and ears harvested together and then ensiled as high-quality feed for cattle, sheep and deer, it would not only improve the nutritional quality of animal feed and thereby improve the quality of milk and meat, but also allow animal manure to be composted and used as organic fertilizer.
In fact, China's level of breeding silage maize varieties has reached the international advanced level, and both quality and biological yield exceed those of developed countries. The bottleneck in industrial development lies in variety promotion. Maize seed companies should actively explore promotion models for silage maize, and farmers should also change their understanding and views of silage maize.
High-quality silage maize can provide cattle with abundant nutrients; it is not merely about solving the problem of cattle having enough to eat.
The reporter's investigation also found that in some places silage maize is called “grass maize”. Farmers believe that only planting grain maize counts as farming, that using good land to “grow grass” is a waste, and that silage maize is only planted on land unsuitable for grain. Management is also generally rather extensive, so the normal yield level of silage maize cannot be brought into play.
“Influenced by the traditional agricultural thinking of taking grain as the key link and instability without grain, growers have a low level of awareness of silage maize and low enthusiasm for planting it.” said Ding Guangsheng, chairman of Henan Dajingjiu Seed Industry Co., Ltd.
The reporter's investigation also found that in some places silage maize is called “grass maize”. Farmers believe that only planting grain maize counts as farming, that using good land to “grow grass” is a waste, and that silage maize is only planted on land unsuitable for grain. Management is also generally rather extensive, so the normal yield level of silage maize cannot be brought into play.
Many people think that harvesting stalks and ears together for silage before the maize is mature is silage maize. Pan Jinbao, a professor at the College of Plant Science and Technology of Beijing University of Agriculture, said: “Silage maize is different from ordinary maize and green feed maize.”
“The most important measure for ordinary maize is yield, while for silage maize quality indicators and biological yield indicators are equally important.” Pan Jinbao said. Compared with ordinary maize, apart from the well-known differences in harvest period and harvested parts, in terms of yield, silage maize has larger ears and higher grain yield, with fresh weight of stalks and ears per mu of more than 10,000 jin and dry weight of more than 2,600 jin.
The higher the feed quality, the higher the intake and the higher the digestibility. Ding Guangsheng used a vivid analogy: “For a cow to produce good milk, it cannot just eat its fill; it must eat well. High-quality silage maize can provide cattle with abundant nutrients; it is not merely about solving the problem of cattle having enough to eat.”
As early as 2010, China issued the national standard Quality Grading of Silage Maize, which at the time was mainly aimed at the livestock feed industry, and seed companies had insufficient understanding of this standard.
In August 2014, the National Crop Variety Approval Committee issued the Main Crop Variety Approval Standards, and the national approval standards clearly listed the quality approval indicators for silage maize: “whole-plant neutral detergent fiber content ≤55%, acid detergent fiber content ≤29%, crude protein content ≥7%, starch content ≥15%.”
What do the two indicators “neutral detergent fiber content” and “acid detergent fiber content” mean? Pan Jinbao explained: “Starch content and neutral detergent fiber content are the most important indicators for evaluating silage maize. Neutral and acid detergent fiber content are indicators specifying the content of cellulose that can be used by animals. The lower the neutral detergent fiber content, the higher the proportion of cellulose available to animals. Acid detergent fiber is very difficult for animals to digest, and specifying acid detergent fiber content is to clarify the upper limit of difficult-to-use cellulose content in silage maize.”
What is the key difference between silage maize and green feed maize? Pan Jinbao said: “Silage maize emphasizes relatively high grain yield and high energy, while green feed maize emphasizes stalk yield; the quality of silage maize is significantly superior to that of feed maize.”