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Report, 2001

Utvidgad tolkning av P-AL för mark- och skördeanpassad fosforgödsling

Mattsson, Lennart; Börjesson, Thomas; Kjell, Ivarsson; Kjell, Gustafsson


Plant available P extracted with a ammonium-lactate solution with pH 3.75 known as the AL-method has been used extensively in Sweden since the beginning of the 1960ies. Interpretation and fertilizer requirement decisions based on analysis data are commonly done without consideration of actual soil data information. An investigation of field experiment data from 72 different sites with altogether 360 experimental yields was carried out in order to find out if and how the variation in the relative P fertilizer could be explained by considering pH, clay content and organic matter content at those sites and the relationship to varying P-AL-values. Both multi-variate-analysis and classical statistical methods were used. Soil organic matter content and soil pH infiuenced the P-fertilizer effect statistically significantly. The effect increased with increasing soil organic matter but decreased with increasing pH. The infiuence of both parameters declined when P-AL increased. On light textured soils (clay<15%) with organic matter content >3 % and pH<6.5 soil data were effective to explain P-fertilizer variations. For PAL- values >8 there were generally only small effects of P-fertilizer. An improvement of the information value of P-AL can be achieved if pH and organic matter content is considered. The quantification of this remains to be carried out


Fosforanalys; pH-värde; Lerhalt; Mullhalt

Published in

Rapport / Sveriges lantbruksuniversitet, Institutionen för markvetenskap, Avd. för växtnäringslära
2001, number: 202
Publisher: Inst. för markvetenskap, Sveriges lantbruksuniversitet

Authors' information

Mattsson, Lennart
Swedish University of Agricultural Sciences, Department of Soil Sciences
Kjell, Gustafsson
Kjell, Ivarsson
Börjesson, Thomas

UKÄ Subject classification

Agricultural Science

URI (permanent link to this page)