Molecular Soil Biology 2025, Vol.16, No.5, 272-286 http://bioscipublisher.com/index.php/msb 280 6 Cultivation and Regulation Technology for Soil Types 6.1 Reasonable close planting and water-fertilizer integration on loam For loam with good fertility and suitable structure, its high-yield potential should be fully utilized, and measures such as reasonable close planting and water-fertilizer integration should be taken to increase the yield per unit area of legume crops. Loam has medium fertility and good water and fertilizer storage capacity, so the legume planting density can be appropriately increased to improve the group light energy and land utilization rate (Ren et al., 2022). Studies have shown that when summer soybeans are planted in loam, when the density increases from 90 000 plants per hectare to 120 000~150 000 plants per hectare, the dry matter accumulation and net photosynthetic rate of the group both increase, but when the density is too dense to 180,000 plants, the group is closed, resulting in insufficient light in the lower part. Therefore, it is generally recommended that summer soybeans be planted densely to about 120 000 plants per hectare on suitable loam, which can significantly increase yield without excessive competition. Dense planting requires sufficient water and fertilizer supply to support a higher group biomass. This requires the use of efficient management methods such as water-fertilizer integration, and fine regulation according to the laws of crop water and fertilizer requirements. In some soybean demonstrations in Northeast China and North China, the drip irrigation + solution fertilizer application technology was promoted to achieve water and fertilizer supply on demand in stages during the growth period, saving more than 30% of water compared with traditional irrigation and fertilization and increasing yields (Zhang et al., 2021). Loam itself has moderate water permeability and fertilizer retention. Combined with drip irrigation and fertilization, it can further reduce deep leakage and nutrient fixation, allowing more water and fertilizer to be used for crop growth. The experiment of Ren et al. (2022) pointed out that when soybeans on loam soil were managed with "organic and inorganic combined fertilization + higher density + water and fertilizer integration", the net photosynthetic rate and PSII light system efficiency of soybeans were significantly improved, and the final grain yield increased by more than 12% compared with traditional management. In fields with good loam soil, mechanized precision sowing and real-time monitoring can also be implemented, and the irrigation and fertilization cycle can be dynamically adjusted according to soil moisture conditions to ensure that soil moisture and nutrients are in the optimal range (Alemneh et al., 2020). On relatively ideal loam soil, the yield potential of legume crops should be fully tapped through advanced and applicable cultivation techniques, so as to achieve high yield and high efficiency by making the cultivation dense but not weak and the fertilizer and water coordinated. 6.2 Drainage and deep tillage management in heavy clay soil For soils with heavy texture and poor drainage (such as tidal soil, clay black soil, etc.), the focus of cultivation regulation is to improve field water management and soil tillage mode to prevent waterlogging and promote rooting. A complete field drainage system should be established. Timely removal of field waterlogging during rainy seasons or during the critical period of crop growth can significantly reduce the incidence of clay soil waterlogging. In practice, ditching and soil management technology is often used, that is, the combination of ridge ditch and side ditch, so that the field can basically drain the surface water within 24 hours after rain. For low-lying and flood-prone plots, pre-digging drainage ditches before rain and adding water collection pits on the edge of the field are also effective measures. Through these engineering measures, the soil oxygen content is guaranteed and the root system of legumes is maintained healthy. Secondly, deep tillage and reasonable crop rotation are implemented in autumn to improve the tillage layer. In clay regions, plowing the soil after autumn harvest when it is dry can break the bottom layer of the plow and loosen the soil by freezing and thawing. Deep plowing can promote the taproots of soybeans to penetrate deep into the soil layer to absorb water and nutrients, thereby enhancing stress resistance. Studies have shown that deep plowing combined with deep loosening on heavy clay soil can make the soil three-phase ratio of the 15~25 cm soil layer approach an ideal state, increase the growth space of soybean roots and the depth of root nodule distribution. Rotating legumes with moisture-tolerant rice or flood-tolerant crops can also alleviate the problem of soil structure deterioration caused by continuous bean planting. On clay, it is advisable to select flood-tolerant varieties and appropriately postpone the sowing period to avoid the rainy period during the seedling stage. In breeding practice, a number of flood-tolerant soybean lines have been cultivated, and the survival rate under 24-hour waterlogging conditions is significantly higher than that of ordinary varieties (Gangana Gowdra et al., 2025). These varieties can be planted in flood-prone clay plots to
RkJQdWJsaXNoZXIy MjQ4ODYzNA==