Jiangsu Academy of Agricultural Sciences, East China Scientific Observing and Experimental Station of Development and Utilization of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China.
Aarhus University Centre for Circular Bioeconomy, Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark.
Sci Total Environ. 2019 Dec 10;695:133845. doi: 10.1016/j.scitotenv.2019.133845. Epub 2019 Aug 8.
Estimating soil erosion and nutrient losses from surface runoff in paddy fields is essential for the assessment of sustainable rice (Oryza sativa L.) production and water quality protection. Different rice establishment methods have been used in the last three decades in Asia; however, it is still unclear how these methods influence sustainable agriculture and environmental protection in humid areas. The aim of this study was to evaluate the impacts of rice establishment method on soil erosion and phosphorus (P) losses from surface runoff in Hydragric Anthrosols under a subtropical monsoon climate. Total suspended solids (TSS), total P (TP), dissolved P (DP), and particulate P (PP) runoff losses were measured under four rice establishment treatments in 2013 and 2014, including traditional manual transplanting (TT), mechanical transplanting (MT), dry direct seeding (DD), and wet direct seeding (WD). The results showed that the seasonal TSS in the runoff varied from 59.9 to 829.8 kg ha in the two years. Compared with TT, the DD significantly increased the TSS by 481% in 2013 and by 349% in 2014, while the WD significantly increased TSS by 783% in 2013 and by 571% in 2014. In the 2013 and 2014 rice seasons, the field-observed TP runoff losses were from 0.18 to 1.51 kg ha. Compared with TT, the DD significantly increased the TP lost by 222% in 2013 and by 197% in 2014, whereas the WD significantly increased the TP lost by 483% in 2013 and by 387% in 2014. However, the TSS and P losses from the MT and TT were similar in both years. The PP runoff losses accounted for 58-77% of the seasonal TP lost. These findings demonstrate that the conversion of traditional manual transplanting to direct seeding increased soil erosion and P runoff losses in subtropical China.
估算稻田地表径流引起的土壤侵蚀和养分流失对于评估可持续水稻（Oryza sativa L.）生产和水质保护至关重要。在过去的三十年中，亚洲地区采用了不同的水稻种植方式；然而，这些方式如何影响湿润地区的可持续农业和环境保护仍不清楚。本研究旨在评估在亚热带季风气候下，水稻种植方式对水耕人为土中土壤侵蚀和磷（P）流失的影响。2013 年和 2014 年，在四种水稻种植方式下（传统人工移栽（TT）、机械移栽（MT）、旱直播（DD）和水直播（WD））测量了总悬浮固体（TSS）、总磷（TP）、溶解磷（DP）和颗粒磷（PP）径流水流失。结果表明，两年间径流水流失的季节性 TSS 变化范围为 59.9 至 829.8 kg ha。与 TT 相比，2013 年 DD 使 TSS 增加了 481%，2014 年增加了 349%，而 WD 使 TSS 在 2013 年增加了 783%，在 2014 年增加了 571%。在 2013 年和 2014 年的水稻季，田间观测到的 TP 径流水流失量为 0.18 至 1.51 kg ha。与 TT 相比，2013 年 DD 使 TP 流失增加了 222%，2014 年增加了 197%，而 WD 使 TP 流失在 2013 年增加了 483%，在 2014 年增加了 387%。然而，MT 和 TT 的 TSS 和 P 流失在两年间相似。PP 径流水流失量占季节性 TP 流失量的 58-77%。这些发现表明，在中国亚热带地区，将传统的人工移栽改为直播会增加土壤侵蚀和 P 径流流失。
