On Changes in Inputs and Outputs of Agricultural Mineral Nutrients (e. g. Ca, Mg, K and Si) in Finland Between 1950-75 - with Discussion on Problems and Solutions

The role of pure or semi-pure mineral elements has changed in the nutrition of agricultural soils during the 20th century.According to an old database potassium mineral fertilizers, K.fm, composed in the 1920's ca 8 % and manure (recycled, rcl), K.rcl ca 92 % of the total potassium fertilization (K.ft).In the 1970's the proportion of K.fm increased upto little over 70 %.About similar increase occurred in other main mineral nutrients (N, nitrogen and P, potassium).Strong increase in NPK and in Ca (mainly in liming agents) supplementation caused dilution of other mineral elements in soil, food and recycled soil nutrients (manure).Based on this same database (economic and ecologic survey) mean input of total potassium (K.ft) in period 1920-60 was annually ca 5 (5.1) kg lower than K content in yield (K.yi).This long-lasting difference can be seen as an obvious sign of coincidental weathering of soil minerals, silicates, causing coincidental K, Mg and silicon (Si) liberation, too.Excess Mg, labeled Mg.we, approximated by Mg/K ratio in groundwater (0.77), composed ca 50 % of the Mg in yield before 1950.The rapid decrease in Mg and Si supply in the 1950's and the stop in 1961 is represented as one additional cause for the rapid increase of male and female CHD mortality since 1957.This article is discussing on effects (or associations) of weathering and recycling of soil nutrients on mineral composition of soil, food, fodder, manure, groundwater, fishery and carbon binding, as well as participating in some health indicators.Changes caused by food processing are mainly excluded in this assessment.Conclusions: Weathering of agricultural soils has been an important factor in the 20th century in the dietary supply of magnesium silicon and several microelements.Enhanced weathering of silicates as promoted by ice-ages can rejuvenate our biosphere, improve health of plants, livestock, humans and the globe, e.g. by carbon capturing.