Tree Genetics and Molecular Breeding 2025, Vol.15, No.4, 168-175 http://genbreedpublisher.com/index.php/tgmb 169 yields. The principle of this method is that water can help dissolve and absorb fertilizers, and with sufficient nutrients, crops can also use water more effectively. When combined, the two can improve the soil, make plants grow faster and use resources more economically (Xing et al., 2024). Studies have found that the combination of fertilizer and water can improve soil structure, make microorganisms and enzymes in the soil more active, and also reduce fertilizer waste and environmental pollution. It is a green and efficient agricultural method (Xing et al., 2024). 2.2 Physiological responses of Camellia to water-nutrient synchrony The combined response of Camellia oil (Camellia spp.) to water and nutrients is very obvious. For instance, the combination of water with nitrogen and phosphorus can affect the stem diameter, chlorophyll content and unit leaf weight of seedlings, as well as plant height and photosynthesis. The research also pointed out that if the water content is 55% of the field capacity, and nitrogen is applied at 5.43 grams per plant and phosphorus at 2.40 grams per plant, such a formula can make the Camellia oleifera seedlings grow best and the leaves also grow well. However, too much nitrogen can inhibit photosynthesis, and too little nitrogen or phosphorus can also cause poor leaf growth (Luo et al., 2024). On tea plants, nitrogen has the greatest impact on dry matter, followed by water and phosphorus. The combination of these three is also very helpful for increasing yield (Wang et al., 2016). 2.3 Technical approaches: drip fertigation, slow-release fertilizers, and scheduling strategies In fertilizer and water management, there are three common methods: drip irrigation fertilization, slow-release fertilizers, and intelligent control systems. Drip irrigation fertilization delivers water and fertilizer to the roots of crops through pipes. This method is very accurate and relatively water-saving and fertilized. It is a frequently used approach in agriculture nowadays (Lin, 2024; Xing et al., 2024). The function of slow-release fertilizers is to gradually release nutrients, allowing crops to absorb them as needed. This not only reduces the frequency of fertilization, but also reduces fertilizer loss and is more environmentally friendly (Xing et al., 2024). Nowadays, many places have also adopted Internet of Things (IoT) and big data technologies. Through these tools, one can check the moisture in the soil, weather changes and how the crops are growing at any time. The system can automatically adjust the supply time and quantity of water and fertilizer based on this information, replenishing what is lacking and providing when needed (Figure 1) (Lin, 2024). As these smart devices become increasingly popular, the water and fertilizer utilization efficiency and growth of Camellia oleifera can also be improved, and the quality of the fruits is expected to become better. These new methods also provide new directions for the digital and intelligent development of agriculture. 3 Classification and Characteristics of Soil Types in Camellia-Producing Regions 3.1 Red soil regions: high acidity, leaching, and clay content In southern China, Camellia oleifera is widely grown on red soil. This kind of soil is slightly acidic (pH is often lower than 6.0), has a lot of clay, and water washes away nutrients relatively quickly. There is not much organic matter in the red soil, the fertility is relatively low, and the trace elements are often uneven (Liu et al., 2018a). When growing Camellia oleifera in this kind of soil, special attention should be paid to the problems caused by acidic soil. Adding appropriate organic fertilizer and adjusting pH can help improve the quality and yield of Camellia oleifera (Yang et al., 2023; Xu et al., 2023). 3.2 Sandy loam and alluvial soils: drainage and water-holding differences In addition to red soil, Camellia oleifera is also commonly grown in sandy loam and alluvial soil. Sandy loam soil is loose, water drains quickly but is not easy to retain water, and nutrients are also prone to loss. The conditions of alluvial soil are quite different. Its parent materials are diverse, and in some places, its water retention capacity is quite good. However, the fertility is related to its composition and the amount of organic matter (Liu et al., 2018b; Tu et al., 2019). Growing Camellia oleifera in these two types of soil requires reasonable water and fertilizer management to maintain the supply of water and nutrients, which is crucial for high yield. 3.3 Rocky-mountain soils and degraded lands: fertility and moisture retention issues In mountainous areas, some areas are calcareous soil or degraded land. These soils have very shallow layers, poor water retention and few nutrients. Although some Camellia oleifera varieties can adapt to calcareous soil, on the
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