论文部分内容阅读
根据6块北疆常年膜下滴灌棉田生育期内4a的土壤盐分监测资料,分析了不同膜下滴灌年限棉田土壤盐分的积累特征。结果表明,膜下滴灌棉田各层土壤盐分随着种植年限的增加先减少后增加。膜下滴灌前6a,棉田各层土壤初始含盐量较高,随着膜下滴灌年限的增加,表层土壤盐分受滴灌淋洗作用不断减小,各层土壤呈脱盐趋势;膜下滴灌种植6a后,由于灌水量的限制,膜下滴灌不具有深层淋洗作用,积盐区土壤盐分随着膜下滴灌年限的增加不断向上扩大,很容易受到温度、灌水制度、地下水位抬升、蒸发等影响,从而在耕作层附件形成多个积盐区,造成土壤返盐,威胁作物生长发育,使作物死亡或减产,甚至造成土壤次生盐碱化。因此,对种植年限6a的棉田要及时进行漫灌,对于膜下滴灌年限更久的棉田要增加漫灌次数或缩短漫灌周期。如果没有漫灌条件,可以尝试在每年生育期末进行1次或2次穿插灌水,从而抑制盐分上移。
According to the monitoring data of soil salinity during the growth period of 6 cotton bolls in North Xinjiang, the accumulation characteristics of soil salinity under different film drip irrigation years were analyzed. The results showed that the soil salt content of all layers of cotton drip irrigation decreased with the increase of planting time and then increased. Under the pre-drip irrigation, the initial salt content of soil in each layer of cotton field was high. With the increase of the drip irrigation time, the soil salt content of surface soil was decreased by drip irrigation and the desalting tendency of soil in all layers. After drip irrigation under mulch, the drip irrigation did not have a deep leaching effect. The soil salinity in the salt accumulation area continued to expand upward with the drip irrigation duration under film, and was easily affected by temperature, irrigation system, elevation of groundwater level and evaporation , Resulting in the formation of a number of salt accumulation zones in the plow layer attachments that cause soil salinization and threaten crop growth and development, resulting in the death or reduced production of crops and even soil salinization. Therefore, it is necessary to diffuse the cotton fields in cotton fields of 6 years of planting time in a timely manner, and to increase the number of flood times or shorten the flood period for cotton fields with longer drip irrigation life under the film. If there is no flood irrigation conditions, try one or two perfusion irrigation at the end of the annual growth period to prevent the salt from moving up.