旱地玉米免耕覆盖土壤水分研究 |
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引用本文: | 籍增顺 洛希图. 旱地玉米免耕覆盖土壤水分研究[J]. 山西农业科学, 1994, 22(3): 7-12 |
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作者姓名: | 籍增顺 洛希图 |
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摘 要: | 免耕整秸秆半覆盖具有明显的保水效果。在一年一作春播玉米区,免耕覆盖抑制了土壤水分蒸发,延长了上层水分向深层分布的时间,玉米秋收后至结冻期间100~200cm土壤水分比不覆盖提高1~1.6个百分点;但结冻期间,土壤水分蒸发基本停止,0~100cm土层水分差异不大;免耕覆盖明显抑制了春季返浆期的土壤蒸发,0~20cm土层比常规耕作土壤水分含量高1~1.7个百分点;玉米生育期间,土壤水分变化规律是,封垄前覆盖与不覆盖间土壤水分差异较大,封垄后差异变小;一般情况下,随深度增加,保水效果减小。免耕本身不具保水作用;在覆盖条件下,耕翻与否对保水作用不大,不论是耕翻还是免耕都必须结合秸秆覆盖;随秸秆覆盖量的增加,土壤第一蒸发阶段持续时间增长,土壤蓄保水量增加;秸秆覆盖一方面具有保水效果,另一方面,降水通过秸秆时又要消耗一定量的水分;免耕覆盖改变了地表状况,有利于雨水的入渗,使得更多的水分下移到剖面深层,为植物利用水分提供了机会;持续干旱情况下,秸秆覆盖土壤水分蒸发量与裸露土壤几乎一样多。
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关 键 词: | 免耕;覆盖;土壤水分 |
Study on Soil Water under No-tillage with Stalks Mulching in Semi-arid region |
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Abstract: | Experimental results at six locations from 1990 through 1992 indicated that, in the regions of growing one crop a year, soil water content at 100~200cm depth during period from October to November increased 1~1. 6 percent point under no-tillage with mulching than conventional tillage. Soil water content of freeze period at 0~100cm depth were nearly the same, but increased 1~1. 7 percent point before spring sowing at 0~20cm depth. As season and depth prograssed, soil water differences between no-tillage with mulching and conventional tillage became small. Under no-tillage without mulching, soil water content was the same with conventional tillage. When a mulch of protective material was used on the surface of the soil, infiltration of water into a mulched soil was maintained at a higher rate for a longer period of time. If the rains were infrequent, the cumulative moisture loss on a mulched soil would lag behind a bare soil but eventually will reach approximately the same moisture content in the total profile. |
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Keywords: | No-tillage Mulching Soil water |
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