Apports en azote d'engrais verts de légumineuses ou non-légumineuses, combinés à une fertilisation minérale ou organique, et effet sur le rendement du blé
|Advisor:||Vanasse, Anne; Chantigny, Martin|
|Abstract:||Estimating the contribution of nitrogen (N) from cover crops (CC) to subsequent crop remains a challenge because CC biomass, N content and biomass mineralization rate vary depending on environmental conditions and management practices. The objectives of this study were (1) to compare N accumulation and biomass production from a mixture of red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) intercropped with barley, or oat (Avena sativa L.), field pea (Pisum sativum L. var. arvense) or oilseed radish (Raphanus sativus L.) grown as catch crops after barley harvest, without N, or with mineral or organic fertilization at CC planting; (2) to determine the influence of CC type and fertilization on N uptake and yield of spring wheat (Triticum aestivum L.) in the next year; (3) to determine the soil-plant N budget over a 2-year cropping cycle. The experiment was repeated twice. The legume CCs generated the greatest N accumulation (63 to 127 kg N ha⁻¹), and intercropped clover mixture resulted in the largest increases in wheat yields (23 to 92 %). Fertilization increased aboveground biomass production in oat and oilseed radish, but had little effect on legume CCs. Oat and oilseed radish were the most efficient at recovering fertilizer N, but had less effect than clover on wheat yields. In conclusion, legume CCs showed limited capacity to use fertilizer N. However, symbiotically fixed N by clover appeared more efficient at stimulating wheat yields the following year, whereas N derived from non legume CCs appeared to be mainly involved in renewal of the soil N reserve.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||27 April 2019|
|Collection:||Thèses et mémoires|
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