Combined Cultivation Pattern Reduces Soil Erosion and Nutrient Loss from Sloping Farmland on Red Soil in Southwestern China

摘要: Crops are usually planted on sloping land in mountainous areas due to limited suitable area. This results serious soil erosion and loss of nitrogen (N) phosphorus (P) degradation water eutrophication. It is important adopt appropriate cultivation practices change this situation. However, few long-term situ measurements available assess the magnitude effects combined patterns nutrient from farmland with red soil, as well quantify N P losses through runoff sediment transport. A field trial cash crop (CC) Nicotiana tabacum was carried out under natural rainfall conditions Yunnan, China during 2014–2017. Four were applied. They included NVF (No fertilizer application + Vertical ridge Film covered), OVF (Optimizing OHF Horizontal OHFR removed). The first two treatments belonged vertical (VR) group, remaining horizontal (HR) group. Results indicated HR group performed significantly better than VR especially treatment, terms producing average (177.12–182.27 mm), (2673.33–3309.17 kg·ha−1), total (TN) (7.58–7.93 (TP) (1.00–1.09 kg·ha−1) runoff, TN (3.53–4.72 TP (2.59–2.76 sediment. lost mainly transport, while On average, decreased sediment, by 39% 73% relative whereas treatment increased 3% 30% those (p < 0.05). Under four patterns, dissolved (TDN) dominant form, which accounted for 71–77% TN. percentage NO3−-N/TN about 45–52%, much higher NH4+-N/TN around 8–10% runoff. Total (TDP) made up 48–59% Redundancy analysis (RDA) showed that pH three key factors controlling loss. In conclusion, recommended because it consistently outperformed other reducing losses.