How to sow summer corn in farmland without watering conditions?

Xiaoman is the second solar term in summer. Xiaoman means that the seeds of summer grain are full, but not yet mature. Only Xiaoman hasn't eaten enough. At this time, the seeds of summer sowing crops such as wheat in northern China have begun to be full, but they are not yet mature, which is about the late stage of milk ripening, so they are called xiaoman. In the small whole season in the northern summer corn region of China, most farmers have started to buy the seeds of Xia Yubo's corn. Today I will talk about the technical points of summer corn cultivation.

1. Sow in time

Summer corn is suitable for sowing in the first half of June. Corn can be sown on the day or the next day of wheat harvest. It is advocated that wheat should be harvested first and then corn should be sown, so as to realize the "one-stop" operation of wheat straw cutting and returning to the field, and corn machinery should be used for precise sowing and fertilization. The sowing date of summer maize with rough dwarf disease can be postponed from June 10 to June 15, and the sowing date of summer maize with serious disease will be postponed by 15 days.

2. Sowing depth

Sowing depth depends on soil quality and water content, generally 4 ~ 5 cm. If the soil is sticky or has high water content, it should be sown shallowly, and the covering thickness is 2 ~ 3 cm. When the soil moisture content is insufficient, deep sowing should be carried out, and the thickness of soil cover should be 6 ~ 8 cm.

3. Planting density

According to the production conditions, climatic conditions, soil fertility, management level and use, reasonable close planting. The recommended planting density of pioneer varieties is 4000-4400 plants/mu of field grain and 4400-4800 plants/mu of silage. In addition to 60 cm and 65 cm row spacing, 40 cm -80 cm row spacing or more than 75 cm wide row spacing can be used for planting, which is beneficial to field management such as fertilization and pesticide application in the later stage.

The most important thing in sowing is to pay attention to quality, realize accurate sowing, ensure uniform plant spacing, consistent sowing depth and reasonable density, and reduce one hole and two kinds. Before sowing in a large area, it is necessary to sow for a short time, and then check the sowing density by touching the soil. If the density is wrong, it is necessary to communicate with the operator to debug the seeder until the plant spacing is uniform and the density meets the requirements. If possible, you can use subsoiling/finger-clip seeder for precision sowing, and plant one seed in one hole to ensure the same sowing depth regardless of seed size. The subsoiling seeder can deeply plough the soil more than 30 cm, break the bottom of the soil plough and promote the corn root system to absorb nutrients. Realize layered fertilization and improve corn.

With the large dosage and wide application of herbicides in wheat and corn, the harm of herbicides in corn is becoming more and more serious, and the hidden harm is widespread. The growth of corn is inhibited (leaf rolling, yellowing, yellowing, etc.). ).), phytotoxicity induced by herbicides such as poor pollination and bald tip can reduce maize yield by more than 100 kg.

When using corn, we should distinguish the varieties and don't blindly use drugs. Do not directly inject water and medicine into the sprayer for mixing, especially the "secondary dilution" during dispensing. Spraying time should be before 9 am or after 4 pm. Pesticides mixed with herbicides should be pyrethroids and carbamate pesticides. When spraying, pay attention to avoid the heart leaves to prevent liquid from filling the heart. Spraying corn seedlings at fixed points after five leaves, rather than spraying all over the ground, so as not to cause phytotoxicity. Bo Shi, a safe herbicide, can be used for field spraying.

Watering method

It is pointed out that drip irrigation is a fertilizer-saving and water-saving irrigation technology which can not only control water quantity, but also realize the integration of fertilizer and water. Drip irrigation can save water and labor input, reduce production costs, reduce the loss of water and fertilizer, optimize the growth environment of soil roots, and realize high yield and high efficiency of agriculture. Fertilization is the guarantee of high yield of maize, and about 50% of maize yield is the contribution of fertilization. The cost of corn fertilization should account for about 50% of the total production input. Fertilization needs to be closely combined with high-yield cultivation techniques to improve nutrient utilization efficiency.

Fertilization requires sufficient seed fertilizer, heavy topdressing and light topdressing, and the ratio of nitrogen to phosphorus is not less than 1.5: 1. When sowing, apply phosphorus and potassium fertilizer, and apply 20 kg of diammonium phosphate, 5 kg of urea, 20 kg of potassium sulfate and 0/-2 kg of zinc sulfate per mu of zinc-deficient land. Or 40-50kg of long-acting slow-release special compound fertilizer, with corn potassium content of more than 10% and total nutrient content of more than 40%. Strip application or furrow application is 8- 12 cm away from the plant and 10- 15 cm deep, and the fertilization amount of corn can also be selected according to different yield levels.

Corn needs fertilizer and water most when it enters jointing stage. When the spread leaves of corn grow to about 6- 10 (above the knee of adults), if there is no fertilization, the yield will be irretrievable. Generally, it is recommended to apply 20-30 kg urea topdressing at the big bell mouth stage, strip application or furrow application, closely covering the soil, deep application to promote large ears and more grains, and irrigation after application to prevent premature aging.

Corn seedling stage is mainly used to control underground pests such as Spodoptera exigua, black cutworm, grub, needle worm and so on. Once underground pests occur, it is difficult to control, and seed coating must be the main method before sowing. The coated seeds can be directly selected. If the underground pests are serious, it is suggested to irrigate the roots with 52.25% chlorpyrifos 100ml or phoxim at night, or stir-fry the above drugs with wheat bran to disperse the ridges. In addition, it is necessary to control Laodelphax striatellus and rough dwarf disease in maize seedling stage. In the early stage of rough dwarf disease, 20% imidacloprid and foliar fertilizer should be sprayed evenly and thoughtfully to ensure the control effect.

The main control measures are corn borer with small horn mouth and large horn mouth. Spray 30 liters of water per mu to control proud enemies or righteous forces; At the same time, reduce the toxins produced by insect feeding and mildew, improve the quality of grain and treat armyworms. After tasseling, it mainly controls diseases such as spot disease, rust and bacterial wilt. Spot disease can be controlled by spraying (birun) benalachlor EC; Spraying 10% difenoconazole wettable powder at the early stage of corn rust. Spraying time should be before 10: 00 in the morning or at night, once every 5-7 days, and spraying continuously for 2-3 times.