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Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau.

Qi J, Nie Z, Jiao T, Zhang D - PLoS ONE (2015)

Bottom Line: The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%.Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration.Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

View Article: PubMed Central - PubMed

Affiliation: College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China.

ABSTRACT
Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

No MeSH data available.


Related in: MedlinePlus

Interactions between defoliation regimes (cut to 1, 3 and 5 cm above ground) and fertiliser application (low, medium and high) on the protein content (%) of (a) Elymus nutans, (b) Kobresia humilis, (c) Melissitus ruthenica and (d) dead matter, and (e) the mean.Bars represent the standard error of the mean; **P < 0.01; *P < 0.05.
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pone.0141701.g003: Interactions between defoliation regimes (cut to 1, 3 and 5 cm above ground) and fertiliser application (low, medium and high) on the protein content (%) of (a) Elymus nutans, (b) Kobresia humilis, (c) Melissitus ruthenica and (d) dead matter, and (e) the mean.Bars represent the standard error of the mean; **P < 0.01; *P < 0.05.

Mentions: The crude protein content was generally higher in M. ruthenica (> 9.5%) than in other species (< 6.5%) and dead matter (< 5%). There were significant (P < 0.05 or 0.01) interactions in the crude protein content of E. nutans, K. humilis and M. ruthenica, dead matter or the mean between the defoliation treatments (Fig 3). For E. nutans, the crude protein content of the herbage increased from low P to medium P when the pastures were cut to 3 or 5 cm above ground, and declined from medium P to high P, particularly for the 5 cm defoliation treatment (Fig 3a). The crude protein content of the herbage remained unchanged regardless of P application when pastures were cut to 1 cm above ground. For K. humilis, the crude protein content of the herbage decreased from low P to medium P, then increased from medium P to high P when the pastures were cut to 3 or 5 cm above ground (Fig 3b). However, the crude protein content of the herbage for the 1 cm defoliation treatment changed in an opposite manner to the 3 or 5 cm defoliation treatments. For M. ruthenica, the crude protein content of the herbage increased from low P to medium P, then decreased or remained at similar level from medium P to high P when the pastures were cut to 3 or 5 cm above ground (Fig 3c). However, the crude protein content of the herbage for the 1 cm defoliation treatment increased with increasing P rates. The crude protein content of the herbage for the dead matter and the mean (Fig 3d and 3e) followed a similar trend as for M. ruthenica.


Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau.

Qi J, Nie Z, Jiao T, Zhang D - PLoS ONE (2015)

Interactions between defoliation regimes (cut to 1, 3 and 5 cm above ground) and fertiliser application (low, medium and high) on the protein content (%) of (a) Elymus nutans, (b) Kobresia humilis, (c) Melissitus ruthenica and (d) dead matter, and (e) the mean.Bars represent the standard error of the mean; **P < 0.01; *P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4626130&req=5

pone.0141701.g003: Interactions between defoliation regimes (cut to 1, 3 and 5 cm above ground) and fertiliser application (low, medium and high) on the protein content (%) of (a) Elymus nutans, (b) Kobresia humilis, (c) Melissitus ruthenica and (d) dead matter, and (e) the mean.Bars represent the standard error of the mean; **P < 0.01; *P < 0.05.
Mentions: The crude protein content was generally higher in M. ruthenica (> 9.5%) than in other species (< 6.5%) and dead matter (< 5%). There were significant (P < 0.05 or 0.01) interactions in the crude protein content of E. nutans, K. humilis and M. ruthenica, dead matter or the mean between the defoliation treatments (Fig 3). For E. nutans, the crude protein content of the herbage increased from low P to medium P when the pastures were cut to 3 or 5 cm above ground, and declined from medium P to high P, particularly for the 5 cm defoliation treatment (Fig 3a). The crude protein content of the herbage remained unchanged regardless of P application when pastures were cut to 1 cm above ground. For K. humilis, the crude protein content of the herbage decreased from low P to medium P, then increased from medium P to high P when the pastures were cut to 3 or 5 cm above ground (Fig 3b). However, the crude protein content of the herbage for the 1 cm defoliation treatment changed in an opposite manner to the 3 or 5 cm defoliation treatments. For M. ruthenica, the crude protein content of the herbage increased from low P to medium P, then decreased or remained at similar level from medium P to high P when the pastures were cut to 3 or 5 cm above ground (Fig 3c). However, the crude protein content of the herbage for the 1 cm defoliation treatment increased with increasing P rates. The crude protein content of the herbage for the dead matter and the mean (Fig 3d and 3e) followed a similar trend as for M. ruthenica.

Bottom Line: The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%.Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration.Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

View Article: PubMed Central - PubMed

Affiliation: College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu, People's Republic of China.

ABSTRACT
Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

No MeSH data available.


Related in: MedlinePlus