Soil Micronutrients-Unsaid

Abstract

Micronutrients are essential plant mineral nutrients taken up and utilised by fruit crops in very small quantities. They constitute in total less than 1% of dry weight of most plants. Micronutrients increase the quality and yield of fruit trees. Besides they play multiple roles in fruit development for example formation of growth hormones, chlorophyll formation, oxidation-reduction reactions, colour development, etc. Plant growth and development may be retarded if any of these elements is lacking within soil or is not adequately balanced with other nutrients. Factors such as soil pH, organic matter, temperature, soil type and moisture are important determining factors for the availability of micronutrients (Fageria et al, 2001). In recent years however deficiencies of micronutrients have been diagnosed more frequently by farmers due to greater amount of intensive cropping, high demand of modern crop cultivars, losses through leaching and so on (Scherer, 2001). Micronutrient deficiency is usually corrected by addition of micronutrient containing compounds such as, sodium tetraborate (14-20% B), boric acid (17%B), ferrous ammonium sulphate (14% Fe), zinc sulphate (23-36% Zn), copper sulphate (13-35% Cu), potassium chloride (47% Cl), manganese sulphate (23-25% Mn), ammonium molybdate (54% Mo), nickel chloride (25% Ni) (Lohry, 2007). Without adequate micronutrients, crops can’t reach their full potential in terms of both yield as well as quality. Highest yield of pistachio was produced in two levels of Zn and maximum vegetative growth took place in Zn and Fe treatment, whereas highest of splitting rate was detected in combination of Cu and Fe and lowest one in control, but effect of Zn, Cu and Fe on blankness was not significant (Soliemanzadeh et al., 2013). Since micronutrients are involved in various enzymatic activities, their deficiency causes malfunctioning of plant activities. Response to micronutrients varies from crop to crop and depending upon the soil type and its status. In addition to yield it improves quality of fruit (Bahmanyar and Mashaee, 2010).