Shuitu baochi tongbao (Oct 2023)

Effects of Configuration Ratios for Contour Planting and Replanted Sugarcane on Gully Erosion-Induced Nitrogen and Phosphorus Losses on Slopes

  • Yang Cuihong,
  • Li Yong,
  • Wang Xu,
  • Chen Tingting,
  • Guo Hao,
  • Yang Jiangyi,
  • Wu Zongmeng,
  • Zhou Xiaoqi,
  • Huang Zhigang

DOI
https://doi.org/10.13961/j.cnki.stbctb.20230327.002
Journal volume & issue
Vol. 43, no. 5
pp. 69 – 78

Abstract

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[Objective] The suitable configuration ratios for contour planting and replanted sugarcane on slopes were determined in order to provide technical support for reducing slope ditch erosion and nutrient loss, improving cultivated land quality and rational sugarcane planting in sugarcane planting area. [Methods] Three configuration ratios (high, medium, and low) for contour planting and replanted sugarcane were evaluated. Slope-gully erosion and nutrient losses were determined by field measurements and laboratory experiments at the growth stages of establishment growth (EG), vegetative growth (VG), grand growth (GG), and ripening growth (RG), and the factors influencing erosion and nutrient loss were determined. [Results] ① During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on slopes planted to sugarcane in the Nala River basin were 31.3—66.3 t/hm2, 39.0—82.5 kg/hm2 and 18.0—38.4 kg/hm2, respectively. ② EG was the main stage of gully erosion and nutrient losses in the Nala River basin, accounting for 47.7%—57.7% of the total erosion and nutrient losses. ③ During TG, gully erosion and associated nutrient losses for higher contour ratios (HC) were 33.03%—35.42% lower than for lower contour ratios (LC) (p<0.05), but the losses for medium contour ratios (MC) were not significant compared with those of HC and LC. Gully erosion and nutrient losses of lower replanted ratios (LRp) were 27.41%—32.98% lower than those of higher replanted ratios (HRp), and 21.02%25.86% lower than those of medium replanted ratios (MRp) (p<0.05). Litter cover and root density were the important factors affecting gully erosion and nutrient losses. ④ During TG, TN and TP losses on slopes accounted for 24.1%—39.5% and 107.0%—156.7% of the annual N and P application, respectively. [Conclusion] Planting sugarcane on slopes with a contour planting ratio of greater than 60% and a replanted ratio of less than 30% can effectively reduce soil and nutrient losses on slopes.

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