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.