The changing dynamics of rill erosion on sloping farmland during the different growth stages of a maize crop

Abstract

Rill erosion is a serious concern in the hilly region of China with purple soil, and maize is extensively cultivated in this region. Evaluations of the dynamic mechanisms of rill erosion in sloping farmland areas are particularly important during the maize growing season to determine whether rill erosion can occur. A new ridge tillage (RT) system was designed using local agricultural methods in China. Twelve artificial rainfall experiments were conducted in three 1 × 2 m experimental plots with a slope of 15°, which is a typical slope in the study area. The rainfall intensities were designated as 1.0, 1.5, and 2.0 mm min−1. The rainfall experiments were performed in the field to determine the characteristics of run‐off and sediment transport related to rill erosion processes during different stages of maize growth and to analyse how hydraulic parameters and the sediment yield of the rill erosion process are related. The results showed that rill flow patterns were mainly classified as subcritical transition flow during all the growth stages of maize. The effects of hydrodynamic parameters on the sediment yield were ordered as follows: Reynolds number > stream power > Froude number > shear stress. The total sediment yield varied by stage as follows: seedling stage > jointing stage > mature stage > tasseling stage. The sediment yield and run‐off rate exhibited a linear relationship that was well described at the hillslope scale. To initiate soil loss in sloping farmland areas with purple soil during the maize growing season, the critical hydrodynamic shear stress and stream power must be at least 46.505 Pa and 1.541 N m−1 s−1, respectively.

Temporal variation of soil erosion resistance on sloping farmland during the growth stages of maize (Zea mays L.)

“…Soil anti‐scourability is an important indicator to reflect soil erosion resistance, especially on sloping farmland (Zheng et al, 2014b; Zhou et al, 2010). Our study illustrated that AS increased gradually with time (Figure 5), which was in agreement with previous studies (Luo et al, 2019; Xu et al, 2019; Yao et al, 2020). As shown in Figure 4, the decrease of sediment loss with time caused the increase of AS.…”

“…Maize is the main crop in the area, and the growth stages of maize overlap with the erosive period of regional rainfall on temporal scale (Wang, Ye, et al, 2018). Recent studies reported that soil loss significantly reduced on sloping farmland with maize growth (Luo et al, 2019; Shen et al, 2019) and thus the impacts of maize growth are so great that cannot be neglected (Ma et al, 2015). However, few studies have been concentrated on the continual effects of maize growth on soil erosion resistance for sloping farmland.…”

Effect of natural rainfall on the migration characteristics of runoff and sediment on purple soil sloping cropland during different planting stages

“…Table 1 presents the basic physical and chemical properties of the experimental soil. The surface slope of all plots was 15° (He et al 2018;Luo et al 2019;Wang et al 2019).…”

A Reliable U-trough Runoff Collection Method for Quantifying the Migration Loads of Nutrients at Different Soil Layers under Natural Rainfall

“…The basic physicochemical properties of the top layer soil were pH (6.29), total nitrogen (1.14 g/kg), total phosphorus (0.72 g/kg), total potassium (21.65 g/kg), soil organic matter (14.96 g/kg), soil bulk density (1.22 g/cm 3 ), and soil porosity (53.96%). The surface slope of all grids is 15° [58][59][60].…”