不同类型咸水滴灌对土壤盐分的影响及棉花产量响应

棉花是鲁北平原种植的重要经济作物,合理利用微咸水和咸水资源是解决棉花季节干旱问题的重要途径。通过田间小区试验,以淡水滴灌处理为对照,设置不同盐分梯度的咸水滴灌处理,研究2种类型咸水滴灌对棉田土壤水分和盐分的分布影响以及棉花产量的响应。结果表明,咸水滴灌条件下主要影响棉田40~100 cm土壤水分的变化,碳酸氢钠型和氯化钠型咸水处理对土壤含水量的影响没有显著差异。利用EC值低于8 d S·m~(-1)的咸水进行补灌,棉田0~40 cm土壤盐分积累不明显,灌溉水EC值为10 d S·m~(-1)的氯化钠型咸水灌溉在0~100 cm土壤盐分有明显的积累。滴灌补灌EC值不大于6 d S·m~(-1)的碳酸氢钠型咸水和不大于8 d S·m~(-1)的氯化钠型咸水对棉花产量没有明显的影响,滴灌补灌7 d S·m~(-1)碳酸氢钠型和10 d S·m~(-1)氯化钠型咸水明显降低棉花产量。从土壤盐分的积累和棉花产量来看,在鲁北平原可以利用6 d S·m~(-1)咸水滴灌对棉花进行补灌;利用咸水滴灌,要同时考虑灌溉水盐分的数量和盐分组成,碳酸氢钠型咸水要更加谨慎利用。

Effect of drip irrigation with different types of saline water on soil salt distribution and the response of cotton yield

Cotton is an important economic plant in the Northern Shandong Plain. The rational using of brackish water and saline water is an important method to solve the drought in cotton growth season. Through the field experiment with small plots, taking the fresh water drip irrigation as the control group, the treatments with different levels of saline water were set up to study the impacts of drip irrigation with 2 types of saline water on soil water and salt distribution and cotton yield. The results showed that drip irrigation with saline water mainly impacted the absorption soil water of cotton in 40~100 cm soil layers. There was no significant difference in the impact of NaHCO3 type and NaCl type saline water treatments on soil water content. Supplemental irrigation of saline water with EC=8 dS?m-1 or less didn’t cause significant accumulation in cotton root distribution layers, however, irrigation with EC=10 dS?m-1 NaCl type saline water caused significant accumulation of soil salinity in 0~100 cm soil layers. There was no significant impact on cotton production using supplemental drip irrigation with saline water of EC not greater than 6 dS?m-1 NaHCO3 type and not more than 8 dS?m-1 NaCl type saline water, while, supplemental drip irrigation with 7 dS?m-1 NaHCO3 type and 10 dS?m-1 NaCl type saline water significantly re-duced the cotton yield. Considering the accumulation of soil salinity and cotton production, supplemental drip irrigation with saline water 6 dS?m-1 could be used for cotton in Northern Shandong Plain. When using drip irrigation with saline water, both the salinity and salt composition of irrigation water should be considered. Using of NaHCO3 type saline water as irriga-tion should be cautious.