The increased cost of energy dependent fertilizer and the need to conserve plant nutrients by recycling them have focused attention to organic material sources of fertilizers. One of the cheapest and most available organic substances is rice straw.
Vanadium is a trace element abundant in soils throughout the world. It has been found a useless element especially to productive plants like corn, soybean, tomatoes and ornamental plants like impatiens and petunias.
Mangosteen is a delicious tropical fruit considered to be a veritable health fruit. It has been known to be rich in micronutrients.
Azolla is a small aquatic fern (usually 1-5 cm large) which grows on saturated or moist soil.