[Soil fertility, an unrepeatable gift [agricultural activity]]

analisi del terreno analyse de sol animal domestique animali domestici compost compostage composting composts crop residues domestic animals engrais organique farmyard manure fertilidad del suelo fertilizzanti organici fumier letame lisier organic fertilizers residui colturali residuos de cosechas slurry soil fertility soil testing zootechnie zootechny zootecnia