Micronutrient deficiencies are widespread. 50% of world cereal soils are deficient in zinc and 30% of cultivated soils globally are deficient in iron. Steady growth of crop yields during recent decades (in particular through the Green Revolution) compounded the problem by progressively depleting soil micronutrient pools. In general, farmers only apply micronutrients when crops show deficiency symptoms, while micronutrient deficiencies decrease yields before symptoms appear. Some common farming practices (such as liming acid soils) contribute to widespread occurrence of micronutrient deficiencies in crops by decreasing the availability of the micronutrients present in the soil. Also, extensive use of glyphosate is increasingly suspected to impair micronutrient uptake by crops, especially with regard to manganese, iron and zinc. en.wikipedia.org/wiki/Micronutrient
Posted on: Tue, 10 Sep 2013 13:26:26 +0000