Response of Growth and Grain Yield of Amaranth (A. hypochondriacus) to Combined Manure and Inorganic Fertiliser Pellets and Non-pellets
J. H. Love
Ministry of Agriculture, Kilimo House, P.O.Box 30028–00100, Nairobi, Kenya
R. O. Nyankanga *
Department of Plant Science and Crop Protection, University of Nairobi, P.O.Box 30197–00100, Nairobi, Kenya
*Author to whom correspondence should be addressed.
Abstract
Grain amaranth (Amaranthus hypochondriacus L) has high potential to substitute expensive animal protein because of its high nutritional value and is potential to reduce protein malnutrition in Kenya. However, its production and consumption are low. Nitrogen fertilisation is among the most important factors limiting productivity. Most farmers use manure and little or no fertiliser. Manures alone cannot meet crop nutrient demand over large areas because of the limited quantities, low nutrient content and the high labour requirement. Manure – fertiliser augmented pellets have been suggested as an improved alternative. This study investigates the effects of pellet fertiliser, produced by mixing calcium ammonium nitrate (CAN) and dry cow dung manure on growth and grain yield of Amaranthus hypochondriacus L over a period of two years. The experiment was laid as randomised complete block design (RCBD) with split plot arrangement and replicated three times. The treatments were different combinations of organic and inorganic fertiliser; 0 percent inorganic N and 100 percent organic N, 25 percent inorganic N and 75 percent organic, 50 percent inorganic N and 50 percent organic N, 75 percent inorganic N and 25 percent organic N 100 percent inorganic and 0 percent organic. The controls consisted of non-pelleted combinations and a non fertiliser treatment. All the pellet fertiliser treatments had higher dry matter weight, 1000 seed weight and grain yield compared to control and non-pelleted treatments. Fertiliser combination of 75 percent organic N and 25 percent inorganic N had the highest grain yield while fertiliser combination of 25 percent organic and 75 percent inorganic recorded the lowest grain yield compared to the other combinations. The use of pellet fertiliser increased grain yield and could be used as an alternative, however, recommendation for adoption should be done after economic analysis.
Keywords: Acidic acrisols, grain yield, Kenya, inorganic-organic combination, tropics