Differential Response of Biomass Production and Nitrogen Uptake of Vegetable Amaranth to Two Types of Poultry Manure from Nigeria and Canada

Amaranthus cruentus is one of the sixty Amaranthus species of world. It is widely grown as a green leafy vegetable and for its grain in many tropical countries of Africa, Central and South American, Canada, Mexico and parts of Asia. Depleted soil fertility under intensive cultivation is a major limitation to production of the vegetable. The study investigated the effects of two types of poultry manure on biomass yield and nutrient uptake of Amaranth cruentus in a greenhouse at the University of Manitoba, Winnipeg, Manitoba, Canada in 2011. The experiment was a 2 × 3 × 3 factorial arranged into a Randomized Completely Block Design and replicated three times. The factors were two soil types, two sources of poultry manure and urea, and N rates at 0, 60 and 120 kg⋅N⋅ha−1. Nitrogen uptake by the plants that treated with poultry manure from Canada (PMC) and Urea was 172.5 vs. 171.4 mg⋅pot−1 and 169.5 vs. 163.7 mg⋅pot−1 respectively which were significantly greater than the poultry manure from Nigeria (PMN), 100.6 mg⋅pot−1 and 110.0 mg⋅pot−1 for Red River and Glenhope soil series, respectively. Nitrogen uptake was similar at the N rates of 60 and 120 kg⋅N⋅ha−1 (140.7 vs. 155.6 mg⋅pot−1) in the Red River soil, while N uptake at 120 kg⋅N⋅ha−1 was greater than at 60 kg⋅N⋅ha−1 in Glenhope soil. Shoot dry matter of the vegetable grown in soils treated with PMC and urea was significantly greater than from PMN in Red River soil (10.1, 9.6 and 6.7 g⋅pot−1) and in Glenhope soil (8.8, 8.1 and 6.4 g⋅pot−1). Phosphorus, K, Ca and Mg uptake at 60 and 120 kg⋅