Intensive rotational grazing has positive effects on productivity of rangeland

Abstract

Intensive rotational grazing is a recently proposed rangeland management strategy that has been praised by the public and media but has not been fully proven or widely accepted by rangeland ecologists. In this study, a three-year experiment was performed to evaluate the effects of intensive rotational grazing on the rangeland ecosystem in a typical steppe in Inner Mongolia, China. The experiment involved three treatments of rotational management with the same level of grazing intensity (1 sheep unit per ha in the first year and 1.3 sheep unit per ha for the next two years), including intensive rotational grazing (livestock rotated every 3–5 days), traditional rotational grazing (livestock rotated every 15 days), and continuous grazing (without livestock rotation). In addition, this experiment set up “no grazing treatment” as the reference and represents the widely used policy of “grazing forbidden”. Compared with previous studies, this study first implemented rotational grazing at a low level of grazing intensity to obey the rangeland policy of Chinese governments, which aimed to balance the forage demand of livestock and the ecosystem conservation. The results revealed that the aboveground biomass and root biomass (0–10 cm deep) were significantly higher in the intensive rotational grazing treatment than in the other two grazing treatments. Moreover, the biomass of the dominant species (Leymus chinensis) and its proportion in the community were also higher in the intensive grazing treatment. Intensive rotational grazing could also promote the weight gain of grazing sheep. However, intensive rotational grazing did not improve the carbon sequestration of rangeland. These results indicated that intensive rotational grazing had considerable advantages in realizing the sustainable management of grazing grasslands when grazing intensity was at a relatively low level, which aims to balance plant growth and livestock production of grasslands. Furthermore, our results suggest that intensive rotational grazing is beneficial for promoting the progressive succession of degraded grasslands and providing economic revenue for local herders, thus worth studying in more regions and rangeland scenarios.