@article{fdi:010066002,
  title = {{D}initrogen fixation by the legume cover crop {P}ueraria phaseoloides and transfer of fixed {N} to {H}evea brasiliensis : impact on tree growth and vulnerability to drought},
  author = {{C}lermont {D}auphin, {C}athy and {S}uvannang, {N}. and {P}ongwichian, {P}. and {C}heylan, {V}. and {H}ammecker, {C}laude and {H}armand, {J}. {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{R}ubber tree plantations ({H}evea brasiliensis) are expanding into marginal areas with low soil fertility and long dry seasons with a high risk of soil erosion and drought damage to trees. {I}ntroducing an {N}-2-fixing legume cover crop in rubber plantations may reduce runoff and soil erosion as well as increasing the availability of nutrients but may also increase competition for water. {T}his study quantified the effect of the legume cover crop {P}ueraria phaseoloides on {N}, {P} and {K} nutrition, water status and growth of young rubber trees (three years old in 2007) over a four year period (2007-2010). {T}he plantation was located on a toposequence with a range of soil depths and water storage capacities in northeast {T}hailand. {T}he legume aboveground biomass production and its nutrient content and decomposition rate were measured and the {N}-2 fixation was estimated using the abundance of {N}-15 (delta {N}-15) in the legume. {M}easurements were taken of the tree stem girth and height and tree leaf predawn water potential, nutrient content and greenness. {T}he transfer of {N}2 fixed by the cover crop to the trees was estimated using delta {N}-15 in the tree leaves. {T}he annual biomass production of the legume was 8 {M}g ha(-1) year(-1) and the {N} accumulation by the legume was 250 kg {N} ha(-1) year(-1). {T}he natural abundance method applied to the aboveground components of the legume gave {N}-2 fixation rates varying from 85 to 93% depending on the year. {T}he leaf delta {N}-15 was similar in the three non-legumes ({H}. brasiliensis,{V}etiveria zizanioides and {P}raxelis clematidea) used as reference plants for estimating the {N}-2 fixation. {T}he higher level of {N} and the much lower leaf delta {N}-15 values for the rubber trees intercropped with {P}. phaseoloides, compared to rubber trees growing without a legume cover crop, showed that there was a relatively high transfer of fixed {N} from the legume to the trees, varying from 39% to 46% of tree leaf {N} depending on the year. {N}either {N}2 fixation nor {N} transfer varied significantly along the toposequence. {A}t the bottom of the toposequence, both the nutrient ({N}, {P} and {K}) and water status of trees was significantly improved with the legume cover crop, doubling the tree girth at seven years of age (tree girth: 28 cm, tree height: 700 cm). {H}owever, at the top of the toposequence with low water storage capacity, the legume cover crop improved tree nutrition and growth but reduced the trees' ability, to survive intense drought. {T}hese results raise concern about the resilience to drought of the rubber tree/{P}. phaseoloides system, since the positive effect of the legume on rubber tree nutrition and growth may increase the risk of water stress and tree mortality. {W}ith future changes in climate, an increasing number of areas will be concerned by the question of optimizing the tradeoff between {N} inputs and water availability.},
  keywords = {{R}ubber tree ; {C}over crop ; {N}-15 natural abundance ; {E}cosystem services ; {E}cosystem disservices ; {C}limate change adaptation ; {THAILANDE}},
  booktitle = {},
  journal = {{A}griculture {E}cosystems and {E}nvironment},
  volume = {217},
  numero = {},
  pages = {79--88},
  ISSN = {0167-8809},
  year = {2016},
  DOI = {10.1016/j.agee.2015.11.002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066002},
}