@book{159148,
	author = {Nutrient mobility in soils :accumulation and losses  and Engelstad, Orvis Phillip. and Soil Science Society of America.},
	title = {Symposium on nutrient mobility in soils: accumulation and losses :},
	publisher = {Soil Science Society of America,},
	year = {c1970.},
	address = {Madison :}
}