Planning the vegetation restoration of badlands requires an understanding of the mechanisms associated with seed transport due to runoff and soil erosion. This is particularly important in semiarid environments, such as those found in Pernambuco, Northeast Brazil, where rainfall mostly occurs in the form of intense short-term events with a high potential to trigger strong runoff and soil erosion processes. The aim of this laboratory study was to evaluate the effect of seed morphology, surface slope, soil surface cover conditions, and rainfall characteristics on the transport of moringa (Moringa oleifera Lam.) and neem (Azadirachta indica A. Juss.) seeds in a soil flume under simulated rainfall. Rainfall intensities (45–270 mm h−1) and patterns (uniform, advanced, and delayed) were simulated on a variety of surface slopes (10%, 30%, 50%, and 70%), where 27 seeds of each species were distributed on the soil surface of bare soil or under applied mulching (coconut powder at a density of 8 t ha−1). Seed transport by runoff increased with rainfall intensity and surface slope and decreased with mulching. This study suggests that the application of mulch as an erosion control technique and the use of heavy and flat seeds would help vegetation restoration on steep slopes highly prone to soil erosion.
1Department of Agricultural Engineering, Rural Federal University of Pernambuco, Recife, Pernambuco, Brazil.
2MARE - Marine and Environmental Sciences Centre, Coimbra, Portugal.
3Department of Civil Engineering, University of Coimbra, Coimbra, Portugal.
4Institute of Science and Technology, Federal University of Alfenas, Poços de Caldas, Minas Gerais, Brazil.
Guest Editor: Dr. José Manuel Monteiro Gonçalves.
Address for correspondence: Ms. Cleene Agostinho de Lima, Department of Agricultural Engineering, Rural Federal University of Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, 50910-130 Recife, Pernambuco, Brazil. E-mail: firstname.lastname@example.org
Financial Disclosures/Conflicts of Interest: This work was supported by program for Special Visiting Researcher of the scientific mobility program Science Without Borders, funded by CNPq, Brazil, by the project HIRT—“Modelling Surface Hydrologic Processes Based on Infrared Thermography at Local and Field Scales” (PTDC/ECM-HID/4259/2014 – POCI-01-0145-FEDER-016668), funded by FCT, Portugal, and FEDER.
Received January 26, 2017.
Accepted for publication February 8, 2018.