不同轮耕模式对旱地土壤结构及入渗蓄水特性的影响

为了探索免耕与深松隔年轮耕对土壤结构及入渗蓄水性能的影响,2007-2010年在宁南旱区采用免耕/深松/免耕、深松/免耕/深松与连年翻耕3种耕作模式,对土壤体积质量、团聚体、入渗率及水分利用效率等方面的影响进行了研究。结果表明:与连年翻耕相比,免耕/深松/免耕、深松/免耕/深松处理使0～60cm各土层土壤体积质量平均降低3.5%、6.2%(P<0.05);使0～20cm土层>0.25mm机械稳定性团聚体数量平均分别增加10.3%(P<0.05)和20.3%(P<0.01),>20～40cm土层分别平均增加17.2%(P<0.05)和23.6%(P<0.01)。免耕/深松/免耕处理0～10cm和>30～40cm土层的水稳性团聚体稳定率分别比连年翻耕提高35.1%和45.8%(P<0.05),深松/免耕/深松处理>10～20cm和>20～30cm土层水稳性团聚体稳定率分别提高101.7%和61.7%(P<0.01)。不同轮耕模式显著增强了土壤的入渗性能,提高对土壤水分的有效利用及降水利用率,免耕/深松/免耕、深松/免耕/深松处理降雨入渗率较连年翻耕分别提高35.2%和15.3%(P<0.05),水分利用效率平均提高7.2%和7.7%(P<0.05),降水生产效率平均提高9.6%和10.7%(P<0.05)。

Effects of different rotational tillage patterns on soil structure, infiltration and water storage characteristics in dryland

In order to determine the effects of no-tillage (NT), subsoiling (ST) rotational tillage patterns on soil structure, infiltration and water storage characteristics, the rotational tillage experiments were conducted to study on soil bulk density, aggregate, infiltration rate and water use efficiency in arid areas of southern Ningxia from 2007 to 2010. Tillage treatments comprised NT/ST/NT (no-tillage in first year, subsoiling in second year, again no-tillage in third year), ST/NT/ST (subsoiling in first year, no-tillage in second year, again subsoiling in third year) and CT (conventional tillage in 3 years). The results showed that, compared with CT, the soil bulk density of NT/ST/NT and ST/NT/ST treatments in 0-60 cm soil layers decreased averagely by 3.5% and 6.2%(P<0.05); The number of elastic-stable aggregate (>0.25 mm, DR0.25) in 0-20 cm layer increased averagely by 10.28% (P<0.05) and 20.26% (P<0.01), and which increased by 17.2% (P<0.05) and 23.6% (P<0.01) respectively in >20-40 cm soil layer. The water-stable aggregates stability rate (WSAR) of NT/ST/NT treatment in 0-10 cm and >30-40 cm layers increased by 35.1% and 45.8%(P<0.05), and which increased by 101.7% and 61.7% (P<0.01) respectively in >10-20 cm and >20-30 cm layers. The different rotational tillage patterns significantly enhanced soil infiltration characteristics, improved soil water use efficiency and rainfall use rate; The rainfall infiltration rate of NT/ST/NT and ST/NT/ST treatment increased averagely by 35.2% and 15.3% (P<0.05), water use efficiency (WUE) increased by 7.2% and 7.7%(P<0.05), precipitation use efficiency (PUE) increased by9.6% and 10.7% (P<0.05) respectively compared with CT.