Take all sources of nitrogen into account - soil supply, organic manures and manufactured fertilisers, record when writing your nitrogen plan and calculating nitrogen crop requirements.
Ystyriwch bob ffynhonnell nitrogen – y cyflenwad yn y pridd, tail organig a gwrtaith artiffisial, cofnodwch – wrth lunio’ch cynllun nitrogen ac wrth gyfrif faint o nitrogen sydd ei angen ar eich cnwd.