The most complete summary of the best time for corn sowing and fertilization demand in 2017

Spring corn has the advantages of early sowing, high yield and good economic benefit. However, due to early sowing, the ground temperature is often low and unstable, which is easy to cause rotten seeds. In order to ensure that spring corn seedlings are homogeneous, uniform and strong, and to achieve the goal of high yield and high efficiency, today let's learn about the related problems of spring corn sowing technology. for this reason, let's first find out when is the best time for spring corn sowing all over the country in 2017. In view of this time, dealers should also pay close attention to the stock!

When will spring corn be sown across the country in 2017?

From south to north, there are areas where spring corn is sown from mid-February to early May, and it is generally appropriate to sow when the temperature of 10cm soil layer is more than 10 ℃. The harvest time is also from south to north, with a difference of more than 50 days from late July to mid-September. Its growth is characterized by slow growth at seedling stage, short basal internodes, low ear position, strong plant and strong lodging resistance.

Under normal circumstances, corn sowing time is around April 20, Grain Rain began to sow. The sowing time of northeast corn is from late April to early May, and it can be harvested in late August. Autumn corn can be sowed no later than mid-July and harvested in mid-late October at the latest. Huang-Huai-Hai divides spring corn from summer corn, and spring corn is also sown at this time. Summer corn is sown after winter wheat harvest, about June.

The best time to plant spring corn in different places

Sowing time of spring corn in Shandong. Because the sowing time of spring corn is early and the growth period is long, so the yield is high. Spring corn is generally planted in early April and harvested at the end of August in Shandong area.

Sowing time of spring corn in northeast China. The sowing time is after Grain Rain (about April 20) and before May 10, and the harvest is generally after October 1 and before October 20.

Sowing time of spring corn in the south. Corn in the south can be planted for two seasons. In the case of the Yangtze River Basin, corn sown in spring is usually sown at the end of March and the beginning of April, and can be picked in the first and middle of July.

Sowing time of spring corn in Hebei. Corn is divided into spring corn and autumn corn. Spring corn is sown in late April and early May and can be harvested in late August. Autumn corn can be sowed no later than mid-July and harvested in mid-late October at the latest.

Sowing time of spring corn in Anhui. Usually, after the first rain in spring, it is the best time to grow spring corn. But now in order to prevent diseases and insect pests, it is recommended that spring corn should be sowed early, generally before the middle of April.

Sowing time of spring corn in Hunan. Spring corn is generally sown in the first and middle of April and harvested in the first and middle of August. Summer corn was sown from late May to early June and matured in mid-late September.

In order to have a good harvest of spring corn, here are some points for attention in sowing spring corn:

Matters needing attention in sowing spring corn

1. Soil temperature

In spring sowing, it is necessary to know that the surface soil temperature of 5~10cm is more than 10 ℃ and the air temperature is more than 12 ℃. At this time, sowing can germinate normally.

2. Soil moisture

When sowing, the soil moisture of the plough layer is required to reach 60% to 70% of the field capacity. Generally speaking, if the soil in the plough layer can form a mass and fall loose naturally, then the soil water content is generally about 60%-70%, which is suitable for sowing.

If the soil in hand cannot form a mass, the soil water content is on the low side, so it is not suitable for sowing and needs irrigation or rain sowing.

If the soil is clustered in the hand, but the natural landing cannot be dispersed but the soil mass, then the soil water content is too high, affecting the emergence of seedlings.

3. Sowing depth

Generally speaking, 4~5cm is suitable. If the soil is sticky and the soil moisture is better, it can be shallower. Soil texture is loose, easy to dry sandy land, can be appropriate deeper, but generally not more than 10cm. Sowing is too deep, emergence time is long, consume a lot of nutrients, thin or seedlings can not be unearthed under the surface; sowing is too shallow, easy to blow-dry topsoil, can not produce whole seedlings; sowing depth is different, some seedlings emerge early, some seedlings emerge late or can not emerge seedlings, easy to lead to large and small seedlings.

The above is the sowing time of spring corn all over the country in 2017, and the matters needing attention in spring corn sowing are introduced in detail here. The planting time of corn is also different in different regions and different environments. It is suggested that corn growers should choose the planting time of corn according to the local environment.

Nutrient demand of Maize during the whole growth period

The growth of corn needs to absorb a variety of mineral nutrients from the soil, of which nitrogen is the most, potassium is the second, and phosphorus is the third.

Generally, for every 100 kg seeds, 2.5 kg of pure nitrogen, 1.2 kg of phosphorus pentoxide and 2.0 kg of potassium oxide need to be absorbed from the soil. The ratio of nitrogen, phosphorus and potassium is 1 ∶ 0.48 ∶ 0.8.

Fertilizer application rate = (requirement of planned output to a certain factor-soil supply to a certain factor) / (content of a factor in fertilizer (%) × fertilizer utilization rate (%)), fertilizer utilization rate varies greatly. According to the experiment, the general organic farm fertilizer utilization rate is about 30%, nitrogen fertilizer utilization rate is about 40% 50% (40%), phosphorus and potassium fertilizer is about 30% 40% (30%).

How much fertilizer do you need to apply to the planned 500 kg per mu corn grain? It is assumed that during the soil survey, the soil nitrogen content is 17 kg per mu, phosphorus pentoxide is 6.0 kg, and potassium oxide is 14.4 kg. The nutrient use efficiency of nitrogen, phosphorus pentoxide and potassium oxide in soil are 50%, 70% and 30%, respectively. When the national fertilizer experiment averages 500 kg per mu, 2.9 kg of nitrogen, 1.2 kg of phosphorus and 2.4 kg of potassium are needed for every 100 kg of grain, and the application amount of urea, calcium superphosphate and potassium chloride is calculated (urea contains 46% of available nitrogen, calcium superphosphate contains 16% of available phosphorus, potassium chloride contains 50% of available potassium).

Fertilizer application rate of corn

1. Determine the target output

The target yield is how much corn should be planted in the current year, and it is determined by the soil fertility of the cultivated land. In addition, according to the average yield of corn in the first three years of the plot, the target yield of corn can be increased by 10% and 15%. For example, a certain plot is a highly fertile soil, and the planned yield of corn in that year reached 600 kg. The nutrients of nitrogen, phosphorus and potassium needed for the whole growth period of corn were 15 kg, 7.2 kg and 12 kg respectively.

2. Calculate the soil nutrient supply.

Determine the number of available nutrients in the soil, and then calculate the number of nutrients in 1 mu of land. If the measured value of soil alkali hydrolyzable nitrogen, available phosphorus content and available potassium content are 120mg / kg, 40mg / kg and 90mg / kg, respectively, the total amount of available alkali hydrolyzable nitrogen in one mu of soil is 150000 kg × 120mg / kg × 10 to the negative 6th power = 18kg, the total amount of available phosphorus is 6kg and the total amount of available potassium is 13.5kg.

As many soil factors affect the availability of soil nutrients, all available nutrients in the soil can not be absorbed and utilized by corn, which needs to be multiplied by a soil nutrient correction coefficient. The study on the formula fertilization parameters of various provinces in China shows that the correction coefficients of alkali hydrolyzable nitrogen, available phosphorus and available potassium are 0.3, 0.4 and 0.85, respectively.

The utilization rates of nitrogen, phosphorus and potassium fertilizers are as follows: nitrogen 30% Mel 35%, P 10%-20%, K 40% Mel 50%.

3. Determine the amount of fertilizer applied to corn.

With the amount of nutrients, soil nutrient supply and fertilizer use efficiency needed for the whole growth period of corn, the amount of fertilizer application of corn can be calculated directly. Then the pure nutrient content is converted into the actual amount of fertilizer, which can be used to guide fertilization. According to the data in 1 and 2, the yield of corn is 600 kg per mu, and the amount of pure nitrogen required is (15ml 18 × 0.6) / 0.30 × 14 kg. The amount of phosphorus used is (7.2 × 6 × 0.5) / 0.2 × 21 kg. Considering the obvious aftereffect of phosphate fertilizer, the application of phosphate fertilizer can be halved, that is, 10 kg. The amount of potassium used is (12 ~ 13. 5 × 0.6) / 0.50 × 8 kg. If diammonium phosphate, urea and potassium chloride are applied, 20 kg-22 kg of diammonium phosphate, 22 kg-25 kg of urea and 14 kg of potassium should be applied per mu.

4. Application of micro-fertilizer

Corn is very sensitive to zinc, and zinc fertilizer is needed if the available zinc in the soil is less than 0.5 mg / kg-1.0 mg / kg. The availability of zinc in soil is higher in acidic conditions than in alkaline conditions, so alkaline and calcareous soils are prone to zinc deficiency. In the areas where phosphate fertilizer is applied for a long time, zinc deficiency is easy to be induced due to the antagonism between phosphorus and zinc, which should be supplemented. Commonly used zinc fertilizers are zinc sulfate and zinc chloride, the amount of base fertilizer per mu is 0.5 kg-2.5 kg, seed mixing is 4 g / kg-5 g / kg, and the seed soaking concentration is 0.02% MUE 0.05%. If the compound fertilizer contains a certain amount of zinc, it is not necessary to apply zinc fertilizer alone.

Fertilization method of corn

1. Base fertilizer

2000 kg-3000 kg organic fertilizer, all phosphate fertilizer, 1 pound 3 nitrogen fertilizer, all potash fertilizer as base fertilizer or seed fertilizer. It can be combined with ploughing and ridging and applied into the sowing ditch at one time, so that the fertilizer can be applied to the plough layer of 10 cm-15 cm. All chemical fertilizers can be used as base fertilizers.

2. Planting fertilizer

Growing fertilizer is the most economical and effective method of fertilization. There are many ways to apply seed fertilizer, such as seed dressing, seed soaking, strip application and hole application. In seed dressing, humic acid, biological fertilizer and micro-fertilizer can be selected to dissolve the fertilizer and spray it on the corn seed, so that the fertilizer solution can be evenly stained on the seed surface and sown after drying.

Soak the seeds: dissolve the fertilizer into a certain concentration, soak the seeds in the solution for 12 hours, and sow the seeds immediately after drying.

Strip application and hole application: chemical fertilizer is suitable for strip application and hole application, and the amount of chemical fertilizer used as seed fertilizer is 2 kg-5 kg. But the fertilizer must be separated from the seeds; deep fertilization is better, with a depth of 10 cm-15 cm. Urea, ammonium bicarbonate, ammonium chloride and potassium chloride are not suitable to be fertilizers.

3. Topdressing

The remaining 2x3 nitrogen fertilizer is used as topdressing. Topdressing is divided into four topdressing stages: seedling fertilizer, culm fertilizer, panicle fertilizer and grain fertilizer, with the following two periods as the focus:

Culm fertilizer: topdressing within 10 days after jointing can promote stem growth and young panicle differentiation. Make jointing fertilizer with 1amp 3 of nitrogen fertilizer in topdressing, combined with shovel, the distance between fertilizer and seedling is 5 cm-7 cm.

Ear fertilizer: when the remaining nitrogen fertilizer was applied in the period of 10-15 days before heading, it could promote larger ear and more grains, and had a good effect on grain filling in the later stage.