Réponse de la fertilisation azotée en culture de maïs sur les sols crayeux et limoneux de la région de Givry et suivi du reliquat azoté

In 2014, the CIPF and Grenera (Gembloux Agro-Bio Tech ULg) conducted an experiment to measure the response (quantitative and qualitative) corn yield to fertilization (mineral and / or organic) increasing (6 items 4 repeats).
The experimental plots consisted of two geographically close but different in texture (silty and chalky).
The objectives were to assess:
 the impact of nitrogen fertilization and soil texture on performance,
 the impact of the texture on the production of nitrogen by the ground and the manure (provided in the spring) and
 the relevance of REQUASUD Nitrawal-fertilization advice.
Monitoring of the remaining nitrogen in bare soil (with or without application of manure in four repetitions) highlighted in the context of a rainy year, the greater sensitivity of chalky soil nitrate leaching during the period vegetation.
Comments (yield & nitrogen balance) performed at harvest have confirmed the quality of fertilization advice REQUASUD-Nitrawal: a near maximum yield with a remaining nitrogen to very low harvest (about 40 kg NO3-N /Ha). This suggests that it is possible to get a fairly low APL in a chalky context, contrary to reports commonly APL observations under the control commissioned by the SPW.
Regarding the quality of fertilization advice, estimating the nitrogen supply by the compartments 'soil' and 'manure' seem to be respectively undervalued and over priced in the chalky and generally quite good in the context silty context.
Finally, for the same levels of fertilization, loamy soil yielded 15-20% more yield compared to a chalky soil.