Abstract: This study aimed to evaluate effect of four tillage techniques including conventional tillage (CT), fresh raised-bed(FRB), permanent raised beds(PRB) and zero tillage with control traffic, on flat field(ZT) on soil water dynamics, water retention and its redistribution in 2010. Results showed that, during the period of sowing, jointing, heading and grain filling volumetric soil moistures under PRB treatment on the top of the soil (0 to 20 cm) increased by 8.9%, 7.5%, 24.7% and 17.4%, respectively than FRB. Volumetric soil moisture under ZT treatment on the top of the soil (0 to 20cm) were 15.2%, 3.6%, 11.6% and 4.6% higher, respectively, than CT. Sowing-jointing and jointing-heading periods of spring wheat are two critical stages of water loss. Water loss of PRB and ZT treatments were higher than FRB and CT in sowing-jointing periods. However, water loss of FRB and CT treatments were higher than PRB and ZT at jointing-heading periods. Water loss of FRB and CT treatment are higher than PRB and ZT after heading periods in 0 ～ 20 cm, however, water loss of PRB and ZT treatment are higher than FRB and CT after the heading stage under the 20cm soil layers. The capacity of water vertical infiltration was greater than that of water horizontal infiltration after furrow irrigation infiltration under FRB. Under PRB, the capacity of the water vertical infiltration was the same as the capacity of horizontal infiltration. The soil moisture distribution formed high soil water content area at 100cm of soil profile in bed. Compared with FRB, water under PRB was much easier to enter the ridge by lateral seepage when using the furrow irrigation, and supplied water at the key crop growth stages to ensure crop yield. Therefore, after using permanent raised beds systems under flat and bed planting cultivation for continuities and years, the technology could significantly increase surface soil moisture, and store more water in the soil. In conclusion, permanent raised beds can improve the soil water content, and be highly efficient in water-saving which are propitious to the sustainable development of conservation agriculture in the arid oasis irrigation region. So this study can provide a theorethical basis for the effective water management under permanent raised beds in the arid irrigation legions.

Key words: permanent raised beds, soil water content, redistribution, in the arid oasis irrigation region, spring wheat

摘要： 为明确传统翻耕(CT)、垄作沟灌(FRB)、固定道保护性耕作(PRB)和固定道平作(ZT)4种耕作方式的蓄水保墒作用,研究了4种耕作方式下土壤水分动态和贮水消耗特征以及灌溉后水分再分布过程。结果表明:与FRB相比,PRB 0～20cm土壤体积含水量在播前、拔节、抽穗和灌浆分别高出8.9%、7.5%、24.7%和17.4%。与CT相比,ZT 0～20cm土壤体积含水量在播前、拔节、抽穗和灌浆分别高出15.2%、3.6%、11.6%和4.6%。春小麦播种-拔节和拔节-抽穗是水分损失的2个关键阶段。播种-拔节期PRB和ZT处理水分损失最高,拔节-抽穗期FRB和CT土壤水分损失最高。0～20cm表层,抽穗后FRB和CT土壤贮水消耗高于PRB和ZT,但20cm以下结果相反。FRB垄床水分主要依赖垄沟水分的横向入渗补充,而PRB处理垄沟水分的垂直入渗和横向入渗能力都较强,垄床在100cm处形成含水量高值区。与FRB相比,PRB沟灌水分易于以侧渗形式补充垄床水分,在作物生长关键期能保证土壤水分供给,达到保墒节水的目的。在灌区连续多年采用平作和垄作固定道耕作后,均能显著提高土壤含水量。本试验为固定道保护性耕作水分高效管理措施的制定提供了理论依据。

关键词: 固定道耕作, 土壤水分, 再分布, 干旱绿洲灌区, 春小麦