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在重质土稻区,由于土壤导水率低,渗透性差,如果排水工程不完善,在长期淹灌条件下,必然引起地下水位升高,土壤潴水,造成土壤缺氧,导致二氧化碳分压升高,形成硫化物、低价铁、低锰化合物,并使有机质还原,产生醇、醛类和甲烷,同时也会使硝酸盐还原为有害的亚硝酸盐或游离氨,降低微生物的固氮能力,进而影响稻株对周围物质的吸收和正常的能量交换,直至危害水稻的正常生长,尤其对根的生长速度和活性影响最严重。因此,采取适当措施,改善田壤水文条件,合理控制地下水埋深,提高土壤水势梯度和活度,增加氧的梯度和扩散速率,减少二氧化碳的积累,协调土壤中的水、肥、气、热状况,活化土壤,减少有毒物质的积累。提高养分的有效性,对促进水稻生长发育,提高产量意义十分重
In the heavy soil rice area, because of the low water conductivity and poor permeability of the soil, if the drainage project is imperfect, the underground water level will inevitably rise under the long-term flooded irrigation conditions, the soil will retain water and lead to soil hypoxia, resulting in partial pressure of carbon dioxide The formation of sulfide, low iron, low manganese compounds, and the reduction of organic matter, resulting in alcohols, aldehydes and methane, but also will reduce the nitrate to harmful nitrite or free ammonia, reducing nitrogen fixation capacity of microorganisms , And then affect the absorption of rice plants to the surrounding substances and the normal exchange of energy until the endanger the normal growth of rice, especially on the root growth rate and activity of the most serious. Therefore, taking appropriate measures to improve the hydrological conditions in the hinterland, controlling the groundwater depth rationally, increasing the gradient and activity of soil water potential, increasing the gradient and diffusion rate of oxygen, reducing the accumulation of carbon dioxide and coordinating the water, fertilizer, gas and heat in the soil Condition, activate the soil, reduce the accumulation of toxic substances. To improve the effectiveness of nutrients, it is of great significance to promote the growth and development of rice and increase the yield