Molecular Soil Biology 2025, Vol.16, No.1, 1-15 http://bioscipublisher.com/index.php/msb 8 In addition to its role in stress resistance, potassium plays a significant part in determining the quality of potato tubers. Adequate potassium levels improve the transport of carbohydrates to the tubers, promoting larger tuber size and higher starch content. Studies indicate that potassium application increases the dry matter content of tubers, which is a key quality parameter for both processing potatoes and fresh market varieties. Potassium has also been linked to reduced sugar concentrations in tubers, which is beneficial for frying quality, as it reduces the tendency for tubers to turn dark during frying processes such as making chips or fries (Torabian et al., 2021). Moreover, potassium helps extend the shelf life of harvested potatoes by improving the structural integrity of the tubers, reducing the incidence of physiological disorders, and enhancing storage quality. Potatoes grown with sufficient potassium levels show better resistance to bruising and have improved vitamin C content, which contributes to both the nutritional value and the marketability of the tubers. Thus, potassium not only boosts yield but also ensures that the harvested potatoes meet market quality standards (Bhattarai, 2018). 5.3 Best Practices for Phosphorus and Potassium Application Rates and Timing To maximize potato yield and quality, it is important to apply phosphorus and potassium at the right rates and times during the growing season. Research suggests that phosphorus should be applied at planting or pre-planting to ensure that the nutrient is readily available during the critical early stages of root development and tuber initiation. Studies have found that phosphorus application rates of 60–100 kg P₂ O₅ per hectare are optimal for promoting root growth and enhancing tuber yields, with higher rates providing diminishing returns. Phosphorus is most effective when banded close to the seed or root zone, as this placement improves nutrient uptake efficiency by the developing roots (Bykin et al., 2021). For potassium, the recommended rates vary depending on soil conditions and crop demand, but application rates of 100–200 kg K₂ O per hectare are commonly used in potato production. Potassium can be applied either pre-planting or as a side-dressing during the growing season. Split applications of potassium are recommended in areas with high leaching potential to ensure a consistent supply of potassium throughout the crop's development. Potassium sulfate (K₂ SO₄ ) and potassium chloride (KCl) are commonly used sources of potassium, with potassium sulfate preferred in some regions due to its lower salt index and reduced risk of chloride toxicity (Ali et al., 2021). The timing of potassium application is also crucial for maximizing its benefits. Potassium should be available throughout the tuber bulking period, which typically occurs after the initial vegetative growth phase. Applying potassium at or before tuber initiation ensures that the nutrient is available when the plant’s demand is highest, leading to larger tubers and higher overall yields. Potassium should also be applied in soils with adequate moisture to enhance nutrient mobility and uptake by the roots (Misgina et al., 2016). 6 Organic vs. Inorganic Fertilizers 6.1 Benefits of organic fertilizers, such as compost and manure, in potato cultivation Organic fertilizers, such as compost and manure, play a vital role in improving soil structure and fertility while enhancing potato growth and yield. Organic matter, when added to the soil, helps improve soil water-holding capacity, increases nutrient availability, and supports the development of beneficial microbial communities. Compost and manure release nutrients slowly over time, providing a sustained nutrient supply to the potato plants, reducing the risk of nutrient leaching, and improving soil organic carbon levels. Studies have shown that compost application, such as Kazi compost, can reduce the need for inorganic fertilizers by up to 25% while still boosting yield and tuber quality (Islam et al., 2021). In addition to enhancing soil fertility, organic fertilizers such as poultry and cattle manure provide essential micronutrients, such as zinc and magnesium, which are often absent in inorganic fertilizers. These micronutrients contribute to the overall health of the potato plant, leading to improved resistance to diseases and pests. Organic fertilizers also help to lower soil acidity, which promotes better nutrient uptake by potato
RkJQdWJsaXNoZXIy MjQ4ODYzNA==