Productivity and nutritive value of some cultivated perennial grasses and mixtures in the alpine region of the Tibetan Plateau

Abstract

The productivity and nutritive value of some cultivated perennial grasses, Bromus inermis (B), Elymus sibricus (S), E. nutans (N), Agropyron cristatum (A), Poa crymophila (P) and mixtures B + N, S + A, B + S + A, S + B + N, N + S + A, B + S + N + A, B + N + A + P, B + S +A + P and S + N + A + P, in the alpine region of the Tibetan Plateau were investigated. Elymus nutans and E. sibricus and the mixtures, B + S + N + A, B + S +A + P and S + N + A + P, were most productive with yields of dry matter (DM) of between 11 000 and 14 000 kg−1 of biomass annually in the second harvest year. Acid‐detergent fibre (ADF) concentrations increased (P < 0·05), and crude protein (CP) concentrations and in sacco DM degradability values decreased (P < 0·05) with the maturity of the cultivated grasses. Swards, based on these species and mixtures, have the potential to be the main choices for cultivation in the Tibetan Plateau because they produce more nutrients than other grass species and mixtures. Late August (flowering stage of dominant grasses) is the optimum time for harvesting as the yield of rumen‐degradable CP is highest that of DM relatively high and the DM degradability is satisfactory.

Effect of N fertilizer on the productivity and nutritive values of perennial grass mixtures in the alpine region of Qinghai-Tibetan Plateau, China

“…At each level of N application the more complex mixtures yielded greater (P < 0.05) DM . This supports our previous finding that SM + DW was less productive than SB + SW + DW + CW in the alpine region of the Plateau (Dong et al 2003a).…”

“…In our earlier study (Dong et al 2003a), it was found that perennial grasses grew weakly, stopped growing at the stem elongation stage in the establishment year and became mature or premature in the 2nd and 3rd growing years in the alpine For personal use only.…”

“…To restore degraded grassland and to develop intensive grass-livestock farming systems (Hu 2000) more than 1 million ha of mixed pastures of perennial grass will be established on the Plateau by 2008 according to the report from the Ministry of Agriculture, P. R. China (2001). In our previous studies, several mixtures of some grass species endemic to the Qinghai-Tibetan Plateau were selected for the alpine region of the Qinghai-Tibetan Plateau based on their productivity and nutritive value, as well as the swards' persistence under grazing and weed invasion (Dong et al 2003a(Dong et al , b, 2004a. However, little information on fertilizer management of these grass mixtures is available.…”

Large scale patterns of forage yield and quality across Chinese grasslands

“…Some uncertainties also exist in studies of forage quality. For example, the classical monograph "Rangeland Resources of China" [6] reported the national-scale patterns of forage quality, but it is based on the national grassland resource survey completed during the early 1980s, and mainly focused on the patterns; recent research studies which analyzed forage quality from individual to community levels were mostly conducted at specific sites, and cannot adequately represent the large-scale distribution and factors influencing forage quality [14,[22][23][24]. Hence, for evaluating the animal husbandry potential in China's natural grasslands and improving the scientific management and use of rangelands, it is very necessary to investigate the spatial patterns of forage quantity and quality as well as to explore the factors influencing them based on recent large-scale field surveys.…”

Growth and potential reproduction of Poa crymophila in response to season precipitation shortage in the Eastern Tibetan Plateau, China

“…Although the productivity, nutritive value, technologies of cultivation and seed production of this plant had been reported (Chen et al, 1994;Li et al, 1998;Dong et al, 2003), the effects of drought on its growth and reproduction have not been studied so far. This paper aims to compare the growth and reproduction of P. crymophila responding to water situation separately in the years with rich pre cipitation (in 2005) and poor precipitation (in 2006), and to explore the response strategies of this grass to environmental stress.…”