Röing de Nowina, Kristina
- Institutionen för markvetenskap, Sveriges lantbruksuniversitet
In intensive agricultural systems, efficient nutrient use is necessary for high crop yields as well as for sustainable environmental management. Recent studies in temperate regions indicate that non-exchangeable NH4+-N (NEA), which is fixed in clay minerals, may affect crop productivity and soil N dynamics more than previously thought. To estimate the quantity and plant availability of NEA in Swedish soils, ryegrass (Lolium perenne) was grown in a pot experiment using 18 soils that were collected (0-20 cm depth) from two long-term agricultural experiment series at five locations. Initial NEA, total N and soil K contents were measured, as well as NEA content 56, 112 and 168 days after planting of ryegrass. The results show that the soils (0-20 cm) contained 21-217 mg NEA kg(-1) sieved soil (5 - 300 kg NEA ha(-1)) estimated as corresponding to 0.1 - 5.1% of the total soil N. Long-term application of farmyard manure (FYM) did not increase contents of soil NEA. Long-term application of K fertilizer increased soil contents of AL-extractable K, but there was no significant correlation with NEA content. Concurrent with ryegrass growth, NEA content decreased on average by 16% between day 0 and day 112, indicating that NEA was released from the soil and taken up by the plants.
mobilization of NEA; non-exchangeable ammonium; pot experiment
Acta Agriculturae Scandinavica, Section B - Soil and Plant Science
2006, volym: 56, nummer: 3, sidor: 197-205
Utgivare: TAYLOR & FRANCIS AS
Jordbruksvetenskap
https://res.slu.se/id/publ/10889