Effect of different tillage practice on rain-fed maize yield and soil water/temperature characteristics in the Loess Plateau

Complete film mulch of alternating narrow and wide ridges with furrow planting (CMRF) significantly increases maize yield and water use efficiency (WUE). It has been the dominant mode of maize production in the semiarid Loess Plateau region. However, due to single tillage methods (e.g., conventional tillage and rotary tillage) continuous applied in the CMRF system, it was apparent that soil water infiltration was affected by the soil plow pan. This has caused the top soil layer shallow, which adversely impacted maize growth, grain yield and soil health. In order to eliminate the plow pan, improve soil structure, increase utilization of the limited rainfall, and enhance crop productivity, a field experiment was conducted at Dingxi in the semiarid Loess Plateau region of northwest China in 2012 and 2013. The study determined the effects of different tillage methods on soil water content, soil water storage, soil bulk density, soil temperature, and water use efficiency (WUE) and grain yield of CMRF system in the rain-fed semiarid environment of the Loess Plateau. Maize was grown under four tillage modes — conventional tillage (T1), no-tillage (T2), rotary tillage (T3) and sub-soiling (T4). The results showed that soil water storage in the 030 cm soil depth increased significantly under sub-soiling and no-tillage. Compared with conventional tillage, and rotary tillage, sub-soiling and not-tillage increased 030 cm depth soil water content by 50.0% and 43.7%, and 14.8% and 10.3%, respectively. Soil bulk density in the 510 cm and 1030 cm soil depths were 10.9% and 12.9% lower under sub-soiling than conventional tillage, respectively. Under sub-soiling and no-tillage conditions, soil bulk density increased with increasing soil depth. On the contrary, soil bulk density decreased with increasing soil depth under rotary tillage and conventional tillage. Soil temperature was higher at seedling stage and lower at jointing-to-tasselling stage under sub-soiling than under conventional tillage. This was critical for improving grain yield, biomass and water use efficiency of maize. In 2012 and 2013, two normal-precipitation years, sub-soiling increased by 5.6%6.1% in maize biomass, by 18.6%28.8% in grain yield and by 28.1%32.9% in water use efficiency, compared with conventional tillage. The study showed that under the same rainfall conditions, sub-soiling in combination with CMRF was the most promising agronomic practice in terms of improving soil water storage and structure. It also coordinated relationship between soil water and temperature, and increased maize yield and water use efficiency in the Loess Plateau of China.