Nitrogen enrichment and grazing accelerate vegetation restoration in degraded grassland patches

Abstract

A B S T R A C TA rapid increase in grazing intensity since the 1980s has caused large areas of the Inner Mongolian grasslands to become degraded. Increasing atmospheric nitrogen (N) deposition might exert an important influence on vegetation restoration in these degraded grasslands by increasing available N and relieving N limitations on productivity. However, no previous studies have tested the assumption that increasing N deposition promotes vegetation restoration in degraded grasslands. By conducting a 4-year field restoration experiment with four N addition treatments (0, 5, 10, and 20 g N m À2 year À1 ) and two grazing treatments (grazed and ungrazed), we investigated the effects of N enrichment and grazing on the restoration of patches in which vegetation had been degraded. N addition significantly accelerated the restoration of vegetation-degraded grassland patches regarding both plant cover and diversity. Moderate grazing also promoted the restoration of degraded-vegetation patches in term of both plant diversity and species similarity. Importantly, the positive effects of N addition on the restoration of degraded patches may be augmented by grazing. This study demonstrate that low levels of N enrichment (or increasing atmospheric N deposition) positively impact vegetation restoration in degraded grassland patches, particularly under moderate grazing practices. Our findings provide new insights into the management of severely degraded grasslands through the regulation of N inputs and grazing practices.

Soil Organic Carbon Accumulation in Abandoned Croplands on the Loess Plateau

“…Although a closely coupled recovery of soil C and N was observed, C:N ratio in natural grassland was significantly higher compared to abandoned cropland (Figure ). It means that plant productivity may be N limited at the secondary succession (Quan et al, ). In contrast to our expectation that colonization by plant would improve soil water conditions after land abandonment, we observed soil water contents of abandoned fallows were lower compared to natural grassland (Figure ).…”

Plant growth regulator and soil fertilizer improve production and growing stage of Brachiaria decumbens

“…Nitrogen is an indispensable constituent in several plant-based organic compounds (amino acids, proteins, nucleic acids) as it increases rates of cell division and expansion (Roggatz, McDonald, Stadenberg, & Schurr, 1999) and participates in the formation of protoplasm and new cells, as well as stimulating cell elongation (Wellburn, 1994). Nitrogen applications to recover degraded pasture areas increase water use efficiency and stimulate plant growth, increasing soil cover (Quan, Nianpeng, Zhen, Yunhai, & Yang, 2015). Thus, the aim was to evaluate the effect of different seed types with treatment of a PGR and nitrogen fertilization methods in Brachiaria decumbens cv.…”

Introducing Chicken Farming into Traditional Ruminant‐Grazing Dominated Production Systems for Promoting Ecological Restoration of Degraded Rangeland in Northern China

“…The long‐term intense grazing has resulted in widespread N loss from Chinese rangelands (Bai et al ., ). N fertilisation has been used to restore the degraded rangelands by overgrazing (Schellberg et al ., ; Conant et al ., ; Quan et al ., ). Under our proposed rangeland CF , free‐ranging chickens act as fertilisation distributors.…”

“…*Herdsmen prefer to manage their rangeland by themselves and the members of a local family could afford all these works in practice. rangelands by overgrazing (Schellberg et al, 1999;Conant et al, 2001;Quan et al, 2015). Under our proposed rangeland CF, free-ranging chickens act as fertilisation distributors.…”