How to apply potassium fertilizer to sunflower

How to apply potash fertilizer to sunflowers? We should pay attention to the growing area and wide distribution of sunflowers as edible and oil crops in China. As sunflowers have obvious potassium-loving habits, in order to strive for high yield, we should not only apply certain nitrogen and phosphorus fertilizer, but also pay attention to potassium fertilizer. However, in the actual production, many farmers often find that the same application of potash fertilizer is sometimes effective and sometimes ineffective. Why is that? Sunflower is indeed a potassium-loving crop. According to the test data published in the World Handbook of Fertilizer use, when the average yield is 200,250 kg, the amount of nitrogen, phosphorus and potassium absorbed by sunflower per mu is 8.7 kg, 5.8 kg and 25.6 kg respectively. It can be seen that the demand ratio of nitrogen, phosphorus and potassium for sunflower is 1.5, 1.5, 1.0 and 4.4. In terms of absorption ratio, sunflower is a crop that needs a lot of potassium. The root system of sunflower can be up to 2 meters deep, most of the required nitrogen, phosphorus and potassium are supplied by the soil, and the deficiency should be regulated by fertilization. If too much nitrogen fertilizer is applied, it will increase the risk of lodging and disease, and lead to a decrease in oil content. Sunflowers absorb a large amount of potassium from the soil, and the potassium supply capacity of the soil can vary greatly depending on the soil parent material and ecological conditions. The potassium requirement of sunflower varies with the yield level and variety. For example, high-yielding sunflower hybrids will absorb more potassium. A large amount of potassium absorbed by potassium-loving crops, some of which is a luxury absorption, may not have a significant effect on yield, especially under normal growth conditions. However, under abnormal conditions such as drought, it plays a good role in improving the drought resistance and other stress resistance of sunflower. Sunflowers need to absorb a lot of potassium, but the application of potassium fertilizer is not always particularly effective, why? How can we improve the effectiveness of applying potash fertilizer to sunflowers? That is, the effective condition of applying potash fertilizer? Experts believe that: the first is the soil conditions: the effect of applying potassium fertilizer in the soil with low available potassium content is obvious, at this time potassium application can increase the oil content and oil yield of sunflower. The key lies in how to determine the critical level of soil potassium content. The content level of soil available potassium is the main factor that determines whether the application of potassium fertilizer is effective or ineffective. Planting sunflower on potassium-deficient soil must need potassium fertilizer to obtain a certain high yield. Specific to whether a piece of farmland soil is deficient in potassium, it needs to be measured by a "critical value of soil potassium supply" verified by a large number of experiments, before a conclusion can be drawn. Generally speaking, for soils with rapidly available potassium content higher than the critical level, whether potassium is applied depends on what crops are planted and how much the target yield is. If you plant potassium-loving crops, the target yield is required to be high, even if there is no shortage of potassium in the soil. it is also necessary to choose an appropriate way to apply potassium fertilizer can still achieve results. At present, the critical value of soil potassium supply in China is not a definite value or a line, but a range value, that is, the critical value of soil potassium supply is set in the range of 70mg / kg. For example, in North America, the critical level of potassium available to soil crops in the north is set at between 40mg / kg and 150mg / kg; however, some states have made it clear in their fertilization recommendations that for new high-yield hybrid sunflower varieties, the critical level of soil potassium should be higher than 105 mg / kg in order to achieve good yield. It shows that the effective application of potash fertilizer depends on the requirements of variety and target yield level. In some cases, potassium crops are effective even if there is no lack of potassium in the soil. Of course, I would also like to explain why there is only a range of critical value of soil potassium supply at home and abroad, rather than a number or a line level. Mainly because different soil types, especially different soil texture, the availability of potassium will be very different, the most prominent is the sandy soil to use the low limit, while the clayey soil should use the high limit in the range. The second is the target yield level and variety differences: different crops are planted in the same soil, their requirements for the critical level of soil potassium supply will be somewhat different. The oil content of sunflower seed is very high, and it is a crop with high potassium absorption, which requires a high critical level of soil available potassium. At the same time, the target yield level and the differences between varieties should also be considered. For example, the new high-yield hybrid sunflower requires that the critical level of soil potassium is higher than the general index level in order to obtain good yield and give full play to the variety potential of high yield and high oil. The third is that irrigation conditions have a great impact on the efficiency of potash fertilizer. Especially in the critical growth period, ensuring irrigation can make crops use potash fertilizer effectively. If under drought condition, when sunflower is under water stress, potassium fertilizer is more important than nitrogen fertilizer, potassium application can improve the limited water use of sunflower and reduce the transpiration coefficient of sunflower. Therefore, the application of potash fertilizer under the same drought conditions is helpful to improve the drought resistance of sunflowers. Click to get more sunflower planting technology click to get more nitrogen, phosphorus, potassium fertilizer application technology click to get more fertilizer application technology