Effective fertilization methods for corn

Corn plants are "heavy feeders," so they require one and a half to two times more fertilizer than rice. Therefore, to save on fertilizer while maintaining high yields and economic efficiency, Binh Dien Fertilizer Joint Stock Company has produced many types of fertilizers with high nutrient content, suitable for corn plants.

Although corn belongs to the grass family, related to rice, its stem is not hollow like rice. Perhaps that's why corn needs a lot of water, but it cannot survive in flooded fields. When it's young, even slightly damp soil can harm its growth, and may even kill the plant. In corn, the harvested part for food is the ear of corn located halfway up the stem, not at the top like in rice.

One important characteristic that distinguishes corn from rice is that it is a C4 plant. Plants in this group have a first photosynthetic product with four carbon atoms, not three as in rice. This characteristic is extremely important, allowing corn to produce higher biological and economic yields than rice within the same growth period.

Corn yields are higher than rice yields because corn plants have a higher photosynthetic intensity. On the other hand, to achieve such high biological and economic yields, corn requires a higher amount of nutrients than rice. For example, a corn field producing 10 tons of grain takes away approximately 269 kg of N, 111 kg of P2O5, and 269 kg of K2O, along with 56 kg of Mg, 34 kg of S, and 19 kg of Cl. Meanwhile, to achieve 10 tons of rice with 14% moisture content, rice plants take away approximately 160-180 kg of N, 30-40 kg of P2O5, and 18-210 kg of K2O per hectare.

However, when recommending fertilizer for corn, it's not simply a matter of which nutrient the plant takes more of; the amount applied should also be based on the soil's ability to supply the plant. For example, for medium- and late-maturing corn varieties grown on alluvial soil, in addition to 8-10 tons of well-rotted manure, 150-180 kg N (326-391 kg urea), 70-90 kg P2O5 (430-560 kg superphosphate or fused phosphate), and 80-100 kg K2O (133-167 kg potassium fertilizer/ha) should be applied. On degraded soil, the recommended amount of potassium fertilizer should be increased by about 50%.

The principle of fertilizing corn is based on how much nutrients the plant takes up; we need to replenish an equivalent amount of nutrients to maintain soil fertility and prevent a decrease in yield in the following crop compared to the previous one.

In the aforementioned recommendations, in addition to the corn stubble remaining in the field which will continue to return organic matter and some minerals, adding 8-10 tons of manure will also contribute a significant amount of organic matter and minerals.

Therefore, the recommended amount of pure fertilizer (N, P, and K) to add will be based on the amount of product we intend to achieve to obtain a yield of 6-7 tons of corn kernels on a large area. The above are recommended amounts of fertilizer from single fertilizers (urea, superphosphate, and potassium).

In practice, many farmers use whatever fertilizer they have available, often combining single fertilizers with NPK fertilizers without understanding the nutrient content of each type of fertilizer. As a result, the quantity and ratio of nutrients vary greatly, leading to wasted fertilizer and low yields. Sometimes, high yields are achieved, but fertilizer costs are quite high, reducing economic efficiency and increasing environmental pollution.

To support corn production in the northern delta region, Binh Dien has produced two varieties of corn, Corn 1 and Corn 2, which have been very well used by farmers. For example, in Tho Xuan, Thanh Hoa, in 2006, farmers used a base fertilizer of 400 kg of manure + 20 kg of phosphate fertilizer + 16 kg of urea fertilizer and 7 kg of potassium fertilizer per 500 m2 plot. This is equivalent to 204 kg of N + 92 kg of P2O5 and 117 kg of K2O/ha; a total NPK of 413 kg.

For the Đầu Trâu fertilizer plot, using two types of corn (Corn 1 and Corn 2), 400 kg of manure, 22 kg of Corn 1 fertilizer, and 10 kg of Corn 2 fertilizer were applied per 500 m2. This is equivalent to 146 kg N + 85 kg P2O5 and 87 kg K2O/ha. The total NPK was 318 kg/ha, resulting in a yield of 5.67 tons of corn kernels/ha, which was 640 kg of corn kernels/ha higher than the control group, and the profit increased by 2,279,600 VND/ha compared to the control group.

Currently, Binh Dien also offers other types of fertilizers such as NPK growth fertilizer 19-12-6+TE, which is very suitable for the early growth stages of corn, used for base fertilization and top dressing when the plants are young. When applying as base fertilizer, only use about 150 kg/ha (15 kg/1,000 m2), apply the fertilizer in rows, then cover with a thin layer of soil before sowing the seeds so that the corn seeds do not come into contact with the fertilizer when germinating.

In the northern provinces, Đầu Trâu fertilizer is used as a base fertilizer before sowing. For the second topdressing, also use Đầu Trâu growth fertilizer, applying it early when the corn has 4-6 leaves, at a rate of approximately 250-300 kg/ha (20-30 kg/1,000 m²). Apply the fertilizer in furrows and then mound the soil around the base of the plants, avoiding applying it too close to the roots to prevent damage.

The NPK 16-6-19+TE fertilizer is suitable for the final topdressing, when the corn is preparing to tassel and differentiate into its cotyledons. The application rate is approximately 250-300 kg/ha (25-30 kg/1,000 m2). The application method is the same as for the second topdressing.

Regarding dosage and frequency of application, the specific instructions are on the packaging; please read them carefully before use. The recommended dosage is for medium to late-maturing varieties and for large areas of land. For specific plots, farmers should combine their experience from previous seasons and years to adjust the dosage accordingly.

According to Bannhanong