Effects of Different Weeding Methods on Runoff Loss of Soil Nitrogen and Phosphorus in Torreya grandis Plantations

JIANG Tao; WU Cheng-chao; PENG Jian-jian; REN Chi; JIN Fan-nian; JIANG Zuo; WU Jia-sen

doi:10.13651/j.cnki.fjnykj.2025.06.006

Abstract：Mastering the effects of weeding measures on the surface runoff and nitrogen(N)and phosphorus(P)loss in Torreya grandis plantations could provide a certain basis for the management of Torreya grandis forest land.Four runoff plot treatments were set up in Torreya grandis plantations at Dongyang Forestry General Farm,Zhejiang Province,including the young forest-weeding,young forest-control,middle-aged forest-weeding,and middle-aged forest-control.The surface runoff volume in 2024 was comprehensively monitored,the concentrations of different forms of N and P in runoff water were analyzed,and N and P loss amounts were calculated.The results showed that the order of surface runoff volume and N/P loss amounts was as follows:young forest-weeding＞young forest-control＞middle-aged forest-weeding＞middle-aged forest-control.The average annual surface runoff in young Torreya grandis forest was about 3.4 times that in middle-aged forest.After implementing the weeding measures,the annual N and P loss amounts in young Torreya grandis forests increased by 4.6%and 5.9%,respectively,compared with the control group,while those in the middle-aged Torreya grandis forests increased by 9.7%and 3.6%,respectively,compared with the control group.The average nitrogen and phosphorus loss amounts in young forests were 3.5 and 3.6 times those in middle-aged forests,respectively.In conclusion,the surface runoff and N/P loss amounts in young Torreya grandis plantations were significantly higher than those in the middle-aged plantations.The mechanical weeding had little impact on soil N and P loss in Torreya grandis plantations,which could be promoted and applied in production in the future.