# Thermoregulation and Soil Moisture Management in Strawberry Cultivation Munched with Sheep Wool
## 4 Discussion  
During the experiment in summer, typically for the Polish climate, the day temperatures ranged between 20 and 30 \({}^{\circ}\)C. At the same time, unusually for this season, several cold nights with temperatures below 10 \({}^{\circ}\)C occurred. The differences between day and night temperatures exceeded several degrees, which is relatively high for Polish climatic conditions. The high air temperatures and solar operation increased the soil temperature during the days. For multiched plots, the excessive sun-induced heating of the soil's surface was prevented, and the temperature increase during the day was minimised. During cold nights, when the soil temperature rapidly decreased, rapid cooling was suppressed for multiched plots, and the temperature remained a few degrees higher. Consequently, the much significantly minimised the daily temperature fluctuations. Analysing the daily temperature fluctuations for the control plot and plots covered with different materials, the plot mulched with wool showed the lowest differences. The wool most effectively mitigated fluctuations between day and night temperatures. The high thermoregulation capacity of wool much results from its good insulating capacities, which have been repeatedly revealed for building insulating materials [27; 28]. For these materials, the thermal conductivity is low, equal to 0.038-0.054 W/m K [29]. This value is similar to or even lower than commonly used insulating materials and significantly lower than the conductivity of straw bales (0.053-0.065 W/m K [30]) and bark (0.074 W/m K [31]). Wool products' low thermal conductivity is caused by trapping small air pockets, creating a natural insulating barrier. Due to the unique wool structure, pockets are formed inside kemp and medullated fibres with hollow or porous medulla and in the micropores placed between fibres. The formation of pockets is facilitated by the uneven surface of the fibres covered with characteristic scales. The numerous air pockets reduce heat transfer through conduction and convection. Additionally, heat loss is reduced by the crimp of fibres and the interlocked structure of the mulch layer. This compact structure reduces airflow and, consequently, reduces heat transfer through convection. In addition to low thermal conductivity, wool has a high specific heat capacity of 1.3-1.7 kJ/kg K. This value is similar to the specific heat capacity of bark 1.3-1.4 kJ/kg K [31] and much higher than that of straw 0.6 kJ/kg K [32]. Due to its high specific heat capacity, the wool absorbs solar radiation heat on hot summer days, reducing the risk of summer overheating. The stored heat is slowly released on cold nights when the surrounding temperature drops to low values. Wool mulch's excellent insulation capacity is essential in the summer during the vegetation season. During winter, the daily oscillations between minimal and maximal air temperatures are much smaller. Due to low air temperature oscillations, many cloudy days, and lower sun rays' impact on the soil, daily fluctuations in soil temperature are much lower. In winter, the soil temperature is influenced mainly by the weather conditions, and mulching has no greater significance, independent of the type of mulch material applied. When analysing soil moisture, it is evident that soil humidity is strictly correlated with weather conditions in the absence of artificial irrigation. For the control plots not covered with mulch, raindrops fall between strawberry plants directly on the soil surface, so soil moisture immediately increases during rains. The falling water interacts with the mulch material for mulched plots before reaching the soil surface. The interactions involve several physical phenomena, including wetting the material's surface, water transport, and water retention. The wettability of the raw wool is significantly reduced. The wool contains hydrophobic contaminants, and a waxy coating covers the fibre's surface scales [33; 34]. Initially, the wool's surface properties make wetting difficult.