Potato growth in moisture deficit conditions
Potatoes are crops that require both soil moisture and humidity. If there is a lack or excess moisture level in the growing process, it is practically impossible to achieve a total yield of high-quality potatoes. The traditional method of water supply to potato planted plots is practiced primarily by accumulating moisture in the soil during the autumn-winter-spring period and reducing its unproductive loss due to evaporation during the growing season and replenishment reserves with rainwater and humidity. In recent years the amount of precipitation in the autumn-winter and spring-summer periods has significantly decreased in the Steppe and Forest zones of Ukraine, which leads to a lack of productive soil moisture. Also, the chances of developing the prolonged drought with a hot period at daytime temperatures higher than 30°C during the potato growing season keep significantly increasing. The demand for new agrotechnical methods and new technologies for growing potatoes in conditions of insufficient soil moisture reserves and extended dry periods during the growing season of potatoes remains relevant. One of the effective solutions is soil mulching. This agricultural technique can reduce water evaporation from the soil during the growing season, replenish its reserves by condensing moisture from the air, and regulate soil temperature and reduce variations in temperature based on mulching timelines, mulch type, and its properties. Modeling the straw mulch layer's effect on moisture's condensation, we revealed that it was significantly influenced by the air temperature above the straw layer and the difference between air and soil temperatures. Our studies have indicated that the amount of accumulated moisture content will be maximum given the thickness of the straw layer of about 15-20 cm at different ratios of air and soil temperatures. Field studies have confirmed an increase in humidity and soil moisture content under a 20-cm layer of straw. This contributed to the increase in potato yield capacity to 26.2 t/ha, 40.9% more than the yield obtained using the traditional potato growing technology.