Effect of mouldboard ploughing and shallow tillage on sub-soil physical properties and crop performance.

摘要

This study was conducted in spring 2011 in a long-term field experiment with the objective of assessing the effect of shallow tillage (ST) and mouldboard ploughing (MP) on important soil physical properties and crop performance. Undisturbed soil samples were taken before sowing from depths of 15-20, 25-30 and 35-40 cm for the determination of saturated hydraulic conductivity (Ks), bulk density (Bd), and water retention capacity in laboratory conditions. Penetrometer resistance (PR) was measured in the field after 1 month of sowing. Plant density of barley (Hordeum vulgare) was also counted after 1 month of sowing. Field water content was significantly higher for MP than ST at 15-20 cm (MP=27%, ST=22.5%) and 25-30 cm depth (MP=29.3%, ST=24.8). Water retention at 1 m suction was also significantly higher in the treatment with MP at the depth of 25-30 cm (31%) than in the ST treatment (27.7%). Significantly higher Ks value was found for ST at depths of 15-20 (13.09 cm h-1) and 25-30 cm (5.10 cm h-1) than for MP (11.15 and 3.52 cm h-1, respectively). Soil Bd was significantly lower in MP treatments for the first two investigated depths (1.43 and 1.44 g cm-3, respectively) than in the ST (1.54 and 1.53 g cm-3). Significant higher PR value was found for ST, especially at the depth of 5-35 cm, but the result was not so high as to reduce the root growth. Water content determined parallel with PR measurement was not significantly different for the two treatments. Plant density as well as crop yield in the ST treatment was higher (3840 kg ha-1) than in the MP treatment (2490 kg ha-1). Therefore, we concluded that long-term ST treatment markedly influenced crop performance and yield by facilitating soil physical properties.