Sesame watering time:
When the soil moisture content during the growth of sesame is close to 50% of the field capacity, or the soil moisture content is lower than 65,438+03% in light loam, 65,438+05% in medium loam and 65,438+06% in clay loam, sesame will wither. In the case of summer drought or autumn drought, sesame can be seen around 10 in the morning. When this phenomenon occurs, irrigation should be organized immediately. When irrigation, we should also consider the weather conditions, and try to avoid irrigation before it rains or when the wind is strong. The irrigation time for a sunny day is before 10 in the morning and after 4 pm.
Sesame watering method:
There are three irrigation methods for sesame: furrow irrigation, border irrigation and sprinkler irrigation. The characteristic of furrow irrigation is to use inter-row water diversion and small water flow to make water penetrate into soil from furrow. Therefore, it has the advantages of reducing the contact area between water flow and the ground, preventing ground erosion, reducing soil hardening, reducing soil evaporation and saving water. The characteristic of border irrigation is to cultivate the soil on the border surface in advance, so that the water flows along the border surface and slope surface and gradually moistens the soil. When border irrigation, attention should be paid to controlling water quantity. When the water flow reaches 80% of the length of the border, you can stop watering and water other border surfaces, so that the border surfaces naturally flow through the whole border surface, and the whole border surface is watered lightly and evenly. Border irrigation is easy to cause ground hardening. Pay attention to shallow tillage after watering, keep soil moisture and break the hardening. Sprinkler irrigation is an advanced irrigation technology, which uses sprinkler irrigation equipment to spray pressurized water into the air and disperse it into water droplets to irrigate crops. Sprinkler irrigation has the advantages of saving water, preventing soil hardening, strong terrain adaptability and easy water control. Especially in the middle and late stage of sesame growth, drought-resistant sprinkler irrigation is more convenient to operate.
Suitable water content in sesame growing period
During the period from sowing to emergence of sesame, the soil water content suitable for sesame emergence is between 15% ~ 25%, especially when 17% ~ 23%, the germination rate is the fastest and the highest. When the soil water content drops below 14%, the emergence rate decreases with the decrease of soil water content, and the emergence speed also slows down. When the soil moisture content falls below 8%, sesame seeds cannot germinate and emerge. However, when the soil moisture content is higher than 23%, the emergence rate and speed also decrease.
The general trend of water demand of sesame from emergence to maturity is that the soil water content required in the two growth stages from emergence to early flowering and topping to maturity is low, while the soil water content required from early flowering to topping is high. The most suitable soil moisture condition for sesame from emergence to maturity is 60% ~ 75% from emergence to initial flowering. 75% ~ 85% from the first flower to the top; 65% ~ 75% from capping to maturity. When the field capacity of soil is less than 50%, sesame wilt usually occurs due to drought. When the water content is above 90%, it is not conducive to growth. When the water content is saturated, it will cause waterlogging and seedling killing.
According to the actual situation, all localities can determine the appropriate irrigation methods. At the same time, according to the growth period and water demand characteristics of sesame, the appropriate irrigation amount should be formulated. Sesame roots are shallow in the soil and have poor waterlogging tolerance, so irrigation should be controlled to avoid flooding. Generally, 20 cubic meters per mu is suitable for irrigation at seedling stage; The water demand during flowering and fruiting is very large, and it cannot exceed 30 cubic meters per mu at a time. Clay loam has strong water holding capacity, and the irrigation amount can be reduced appropriately. Sandy loam has good physical structure and strong air permeability, and the irrigation amount can be slightly higher.
Planting management
1. Weeding: After 3 days of sowing, professional weeding drugs can be sprayed between plants and fields to control the wild growth of weeds.
2. Planting: After the seedlings are planted for more than 10 day and grow 2-3 leaves, remove a part of the over-dense area, and clean it again in a week, so that the interval between each crop is 22-24 cm, and the number of crops in the whole 1 mu is 8000- 10000. Proper distance can make crops receive normal light and make plants flourish.
After sesame blossoms, the nutrient supply at this time accounts for 70%-80% of the total. So at this time, if you want to make your crops grow well, you have to fertilize more. In addition, exogenous root fertilizer can be applied from early flowering to near recession. At this time, everyone should choose to spray special fertilizer on both sides of the leaves on a sunny afternoon, about once every 5-6 days, and the best time is 2-3 times.
Sesame has shallow roots and is slightly drought-tolerant. However, in order to avoid flooding, there is a saying in the agricultural proverb that sesame "harvests after drought, and rain and flood do not meet." This shows that long-term drought will inhibit the growth and development of sesame, leading to a reduction in production, and soil waterlogging will lead to a crop failure. Therefore, only when the soil moisture is suitable can sesame grow well. If the upper buds of sesame plants fall off and the leaves wither around 10, and the leaves gradually recover after high temperature in the afternoon, irrigation should be organized immediately.
Sesame can be watered by furrow irrigation, sprinkler irrigation and drip irrigation, and it is not allowed to be flooded. The most common irrigation methods are furrow irrigation and sprinkler irrigation.
1, furrow irrigation: water is introduced into the furrow for infiltration irrigation, with open water in the furrow and no open water on the furrow; Water flows down the ditch from a height, and the furrow is blocked with straw for irrigation by stages; Combined with artificial watering to prevent leakage and uneven irrigation; Finally, when irrigated to the lower part, the boundary surface permeates, so that water slowly penetrates into the topsoil. In this way, there will be no obvious large-scale waterlogging in the ditch, which is not easy to cause waterlogging reaction and can save water.
2. Sprinkling irrigation: There are two methods: foliar spraying and root spraying. Its advantages are: less water, even spraying water on leaves, giving full play to the absorption of roots, stems and leaves, which can make the canopy play the role of cooling, humidifying and improving microclimate. Although the cost of sprinkler irrigation is slightly higher, it can save irrigation water.
3. Sesame watering time: It is best to water sesame after 17 to avoid the adverse effects of high temperature irrigation on sesame growth. Prepare tools and water sources before irrigation; After irrigation, the ditch must be cleaned to avoid waterlogging, and no irrigation before rain to avoid the harm caused by irrigation and rain. Don't hurt sesame seeds when water flows down the ditch or is used for auxiliary watering, so as to prevent muddy water from being poured on young leaves.