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农业生产中经常遇到各种自然灾害,让广大农民遭受很大的损失,现将有关灾害和防御技术介绍如下。1.干旱干旱是一种因长期无雨或少雨造成空气干燥、土壤缺水的气候现象。在农业生产中,干旱有大气干旱、土壤干旱、生理干旱三种。大气干旱是空气干燥,作物蒸腾十分强烈,致使作物体内严重缺水而受害;土壤干旱是土壤缺水,作物根系不能吸收足够的水分来补偿蒸腾作用的消耗,致使作物体内水分状态恶化而受害;生理干旱是土壤不缺水,但由于其他不良土壤状况的影响(如盐、碱等),使根系吸收不到水分,造成作物体内缺水受害。
In the course of agricultural production, we often encounter various natural disasters, so that the vast majority of farmers suffer great losses. We will now introduce the related disaster and defense technologies as follows. 1. Drought Drought is a climatic phenomenon of air-dry and soil-water shortages caused by prolonged rain or light rain. In agricultural production, there are three types of drought: arid arid arid arid arid arid. The atmospheric drought is air-dry and the crop transpiration is very strong, resulting in serious water shortage in the crop. The soil drought is the soil water shortage. The crop roots can not absorb enough water to compensate for the consumption of transpiration, resulting in the deterioration of the water status of the crop. Physiological drought is that the soil is not water-scarce but due to the influence of other bad soil conditions (such as salt and alkali), the roots can not absorb moisture and cause water shortage in crops.