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盐渍化水稻土的形成和发展,是在土壤水分的参与下进行的,所以在年循环变化中,按其不同季节,有着各自不同的特征和变化规律。1、蒸发期:主要受自然因素的影响很大,所以该期的特点是蒸发量大而降雨量少,土壤水分处于最低值,常有早春干旱现象。但由于冻土层的顶托,上层融冻时土壤出现“返浆现象”。2、饱和期:该期为水田保水阶段,所以土壤水分处于饱和状态,因此该时期土壤水分的运行比较活跃,而且在长期淹灌条件下,对水稻土的形成和发展起到很大作用。3、回降期:稻田撤水后,土壤水分在自然条件下开始消耗,特别是在水稻收割后,地面裸露,土壤水分含量将迅速下降,因此为秋季农田翻耙地作业创造良好条件。4、结冻期:盘锦地区结冻期大约100天左右,冻深1米左右,在此期间,土壤水分以固态存在土体中,因此比较稳定。表层土壤水分虽在低温条件下,仍有缓慢的蒸发而下降。土壤融冻是从上向下和从下向上同时进行,大约在4月下旬化通,融解点在60厘米左右。土壤质地对土壤保水、冻深和融冻期有关。土壤水分垂直运动规律,按土壤层次可分为:强活动层;活动层和弱活动层,土壤水分在强活动层中幅变很大,随着层次的加深而逐渐减弱。
The formation and development of salinized paddy soils are carried out with the participation of soil moisture. Therefore, they have different characteristics and changing laws in different seasons. 1. Evaporation period: It is mainly influenced by natural factors. Therefore, the period is characterized by large amount of evaporation and less rainfall, and the soil moisture is at a minimum, and there is often the phenomenon of early spring drought. However, due to the support of the permafrost layer, the soil appears “backpulping phenomenon ” when the upper layer is frozen. 2, the saturation period: This period is paddy water retention stage, so the soil moisture is saturated, so the soil moisture during this period more active operation, and in the long-term conditions of submergence irrigation, paddy soil formation and development play a significant role. 3, the fall period: water withdrawal paddy, soil moisture began to consume under natural conditions, especially after rice harvest, the ground bare, the soil moisture content will decline rapidly, so as to create a good condition for autumn farmland rake. 4. Freezing period: The freezing period of Panjin is about 100 days and the depth of frozen is about 1 meter. During this period, the soil moisture exists in the soil in the solid state, so it is relatively stable. Although the surface soil moisture at low temperatures, there is still a slow evaporation and decline. Soil freezing is from the top down and from the bottom up at the same time, about the end of April melted, melts at about 60 centimeters. Soil texture on soil water, deep freezing and thawing period. The law of vertical movement of soil moisture can be divided into strong active layer, active layer and weak active layer according to the soil layer. The soil moisture changes greatly in strong active layer and gradually decreases with the deepening of soil layers.