Humic substances for improving potato yield
Harvesting Large Tubers
Humic Substances to Improve Potato Yields
Potatoes are a staple food in the world. They are the fourth most widely grown crop after rice, wheat and maize. Their ability to adapt to a variety of conditions means they can be grown almost anywhere. However, extreme climate conditions such as long heat waves and, most recently, a wet growing year have seriously affected the potato industry and reduced yields. Also a problem is the increasing salinity of the soil caused by improper irrigation and fertilization practices, which further harms the popular tuber. Practical solutions are needed, ideally those that can be implemented quickly and efficiently.
Soil character is critical to tuber growth.
Potatoes thrive in nutrient-rich soil. Soils with a high humus content and a well-sifted structure that ensures balanced moisture distribution contribute to high yields. If the soil is too loose, water supply is impaired and potatoes are susceptible to scab. In heavy soils that warm up slowly in the spring, clods form and this often leads to tuber deformation.
Using humic acids and new varieties to combat salt stress in the soil
However, there are approaches to combating salinity problems. In Egypt, experiments with the humic acid product POWHUMUS® have shown impressive results: the yield per plant and the average size of potatoes increased significantly. In addition, unlike the control group, the leaves of the treated plants did not show external signs of stress, such as the typical yellow salt edges.
Humic acids apparently help to alleviate salt stress. The mechanism is based on the high cation exchange capacity of humic acids, which break down salts in the soil, chelate their cations, such as calcium and manganese, and make them available to plants near the roots, thereby significantly reducing harmful salt concentrations.
In addition to soil cultivation, researchers on the Dutch island of Texel are trying to counteract salinity with new varieties. Potato plants there are sprayed with salt water. Varieties that do not tolerate this are rejected, while others are studied further. The results are promising: tubers that are salt-tolerant could represent a significant solution for affected cultivation areas. Egypt and India have also already expressed their interest in cooperation.
Healthy tuber growth requires sufficient nutrients.
Humic acids also have a strong effect on sandy or heavy soils that are not too saline, as they improve both nutrient uptake and soil structure. This increases the effectiveness of fertilizers while reducing leaching. Humic acid treatment is recommended shortly before sowing seed tubers. This allows the young tubers to meet their increased nutrient requirements and root in the soil more quickly and effectively. Humic acids optimize the carbon-nitrogen ratio directly in the seedlings and create a kind of organic reserve of nutrients. The earlier the crop formation begins in early summer, the less significant damage from late blight will be later. Immediately after planting the tubers, the supply of phosphates is especially important. Humic acids bind phosphorus in the soil near the roots and thus ensure an optimal supply.
The prospect of future years with long periods of heat and drought is not good news for the potato industry. Especially during the tuber filling and starch formation phase, heat and drought can cause problems. In excessively dry soils, many important minerals are present in undissolved form, making them difficult for the potato to absorb – often with serious consequences for plant growth. Humic acids can also play a decisive role here, making these minerals available to the plant and thus ensuring yields even in hot and dry conditions.
Humic acids act as soil conditioners and stimulate potato growth.
Humic acids do not act directly as plant nutrients, but activate beneficial soil life around the potato tuber. The use of products such as POWHUMUS® or LIQHUMUS 18® improves the storage of essential nutrients in the crop. This increases yields, promotes healthy leaves and root growth. The starch reserve in the potato tuber increases, and the potato uses its genetic potential more efficiently. Therefore, it is acceptable for the farmer if the salt content is higher at the beginning or if the soil is heavy or light. The use of humic acids can facilitate cultivation in difficult conditions and help improve unfavorable soil conditions in the long term.
