But the studies looked at high amount of nitrogen--25 kg per hectare (ha) per year on an average--which accumulated in the soil due to excessive fertilizer use.
Kushiyana ngemphumela weluhlolo lwetimphandze, emakilogram ku hekitha langaba Likhulu enitrogen (N) ayaniketwa ngemnyaka. (loku sikalo lesentiwe futsi kumele sitsatfwe ngekuya kwemphumela weluhlolo lwemhlabatsi.)