Nature based solutions
Natural base solutions are a phenomenal approach for sustainable land management by considering the whole processes like erosion processes (detachment, transportation and deposition) and predict its long-term effect on landscape dynamics that determine sediment and water connectivity and its infraction within landscape. It has two types of measures: landscape and soil solutions. Landscape solutions mainly focus on hillslope morphology, runoff pathways, topographic wetness and water and sediment sinks (Ballard et al., 2013; Keesstra et al., 2018). The soil-based solution is mainly based on soil health, which can be explained by soil stability and soil roughness reduce overland flow and associated sediment transport. Vegetative and integrated SWC measures like grass strips trappings of sediment with vegetation and transform over time into a terrace can be seen as nature-based solutions which determines the potential for water and sediment to be transported and trapped through the system (Cerdà & Doerr, 2005; Masselink et al., 2016; Mekonnen et al., 2016). Within the nature-based solutions organic farming is a key management as allow the growth of vegetation and then reduce the raindrop detachment, overland flow velocity and enhance infiltration (Cerdà et al., 2018; Cerdà et al., 2018; Kirchhoff et al., 2017).
Conclusion
To overcome land degradation through sustainable land management, many efforts have been made globally. On the basis of these efforts many research articles have been published to understand the implication of different SWC measures on the biophysical dynamics of the watershed. A critical review was carried out from scientific journal articles to the effect of physical, agronomic, vegetative and integrated SWC measures on soil properties, surface runoff and soil loss. The synthesis reveals that, vegetative and agronomic measures play an important role for soil fertility enhancement and thereby improving soil quality for better production. Whereas structural measures such as terraces, bunds, fanya juu, and conservation tillage have a significant impact on runoff reduction by increasing the time of concentration and decreasing the velocity of running water. The combined implementation of SWC (physical, vegetative and agronomic) measures have also decreased soil erosion and improves the sediment trapping capacity of the landscape.
From this synthesis, research gaps have been identified. The evaluation of SWC measures on soil properties, runoff and, erosion and soil loss should mainly focus on larger scale on the bases of long-term evidences. In addition, the effect of different SWC measures should consider the connectivity concept to understand erosion and hydrological processes at large-scale, which can be addressed using field investigation and modeling tools. This approach finally leads to developing and promoting ecologically sound, economically viable and socially acceptable conservation measures for sustainable land management in agricultural watersheds.