[Ecological grain production - nutrient supply and varieties]

agricultura alternativa agriculture alternative alternative agriculture avena calidad cereal crops climatic factors crop performance crop yield cultivos de cereales disease resistance edaphic factors ensayos de variedades facteur climatique hordeum noruega norway nutrition des plantes performance de culture plant nutrition quality rendement des cultures rendimiento de cultivos resistencia a la enfermedad rotation culturale rotational cropping secale cereale triticum variedades varieties variety trials