Excavated farmland with plastic mulching as a strategy in saving water
and controlling soil salinization in dryland agricultural areas
Abstract
Water shortage and soil salinization in gully farmland comprising
sediment deposited farmland (SF) and excavated farmland (EF) have become
a widespread concern in the loess hilly region. A two-year field
experiment was conducted to assess the soil water content (SWC) and salt
content (SSC) and their effect on the spring maize yield and water use
efficiency in SF and EF. Eight treatments comprising flat cropping
without mulching (1), ridge planting without mulching (2), ridge
planting with plastic mulching (3), and ridge planting with straw
mulching (4) were tested in the SF and EF plots, respectively. The
results showed that the yield was higher in SF than EF, whereas the
water use efficiency was significantly higher in EF because the bottom
water flux was 117.4% higher in SF than EF (P < 0.01). A
significant positive correlation was found between the average SWC and
yield (P < 0.01), thereby indicating that the yield was
severely limited by the SWC. Thus, the higher water use efficiency in EF
has important implications for alleviating water scarcity during
agricultural production in this region. The risk of soil salinization
was decreased greatly by treatment 3 where the SSC was decreased in EF
and SF were 0.09 g kg–1 and 0.08 g kg–1, respectively. In addition,
treatment 3 had the most significant impacts on the yield and water use
efficiency. Our study provided appropriate land type and effective
tillage measure for the sustainable development in dryland agricultural
areas.