Levels of Macronutrients of Leaves of Chosen Plants from Highlands East of Mount Kenya
Mr. Njagi E. Silas, Prof. Jane I. Murungi, Dr. R.N. Wanjau

Abstract
Fast growth in population has led to small scale farming as a result of land sub-division. The small pieces of land are under cultivation throughout which has led to reduction in soil fertility. The use of commercial inorganic fertilizers in these small pieces of land tends to be the ultimate solution in maintaining high yields. Too much use of inorganic fertilizers has led to low amount of organic matter in soil and low soil pH which leads to low rate of decomposition of the little organic matter present. Also, poor peasant farmers do not afford the inorganic fertilizers and do not know which plants have leaves that have high levels of macronutrients which can improve soil fertility so that their farm produce can be high. This study was aimed at investigating levels of macronutrients in leaves of chosen plant found on highlands east of Mount Kenya. The percentage of the macronutrients on the leaves ranged from 0.037 to 1.605 for nitrogen, 0.152 to 0.792 for phosphorous, 0.044 to 1.331 for potassium, 0.354 to 2.034 for calcium, 0.073 to 0.977 for magnesium and 0.883 to 1.153 for sulphur. It was found that species of plants such as Helianthus annus (sunflower), Markhamia lutea (muu), Cordial africana (muringa), Croton macrostachyus (mutuntu) and Tithonia diversifolia (mexican sunflower) from the species studied contains leaves with high percentages of macronutrients. It is recommended that these plants be planted by farmers so that their leaves may be used to make compost manure, make bedding materials for animals (which results to farm yard manure) and/or simply be spread in farms which will improve soil fertility.

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