id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
afs-5853	SAARELA, I.; HUHTA, H.; VIRKAJÄRVI, P.	Effects of repeated phosphorus fertilisation on field crops in Finland 2.Sufficient phosphorus application rates on silty and sandy soils	2006	21	.pdf	application/pdf	14783	611	68	After the rapid build-up of soil P re- serves and the introduction of the placement ferti- lisation technique in the 1960s and early 1970s, earlier field experiments were no longer consid- ered adequate for estimating P fertilisation needs. The CaCl2 meth- od introduced by Houba et al. (1990) extracted lit- tle P from most Finnish mineral soils, indicating a low content of dissolved P in soil solution, or a low intensity of soil P, in agreement with Pw.	cache/afs-5853.pdf	txt/afs-5853.txt