Yield and Iron Toxicity Response of Rice Cultivars to Nitrogen and Phosphorus Application Rates in Lowland Ecology of Moist Savanna of Northern Nigeria

Evaluation of ameliorative effect of nitrogen and phosphorus rates on iron toxicity of lowland rice was examined. Trials were conducted in the Research Farm of National Cereal Research Institute, 2006 and 2007 wet season. The experiment was laid out in a randomized complete block design (RCBD) in split-split-plot arrangement replicated three times. The main blocked consisted of three levels of phosphorus (0, 30 and 60 P205 kg ha-1); the sub-block four levels of nitrogen (0, 30, 60 and 120 N kg ha-1)and the sub-sub-block ten rice varieties (five lowland NERICAs (NERICA L-19, 20, 41, 42 and 60), four improved sativa (FKR 19, TOX 4004, BW 348-1and WITA 4) and one local variety (Ebagichi). Significant interactions (P <0.05) of phosphorus × nitrogen × variety at 42 and 63 DAT were observed on iron toxicity score with significant depression at 30 kg P205 ha-1 of lower nitrogen rates in all varieties except NERICA L-60. Increasing application rates of nitrogen resulted in increase in grain yield, while maximum grain yield was observed at 30 kg P205 ha-1. WITA 4 at lower N application rates and 30 kg P205 ha-1 remained the most promising in terms of grain yield and iron toxicity tolerance in the moist Savanna of northern Nigeria.

Potential of Lablab purpureus accessions for crop-livestock production in the West African savanna

The introduction and use of herbaceous legumes may contribute to agricultural intensification, especially in the context of sustainable crop and livestock production systems. In the context of evaluating different legume species for these systems in moist savanna zone of West Africa, the present study involved the evaluation of 46 accessions of Lablab purpureus (L.) Sweet between 2000 and 2002 at Samaru, Zaria in the northern Guinea savanna of Nigeria to identify accessions with the potential to contribute to grain or forage production and those with the potential for multiple use. Grain yields (0·6–2·4 t/ha) with a mean seed crude protein and phosphorus content of 25·3 and 0·46 g/kg, respectively, were obtained. Dry matter yields (leaf: 0·3–3·1, stem: 0·2–4·6, root: 0·03–0·3 t/ha) were produced between 40 and 140 days after planting. Within this same period up to 1152 kg shoot crude protein/ha, equivalent to 184 kg N/ha, were recorded for accessions. Ten accessions that may contribute to grain production, eight accessions that may contribute to forage production and six accessions with drought tolerance were identified. Some white-seeded accessions (Grif 1246, ILRI 4612 and PI 183451) with good grain and forage yield and high-protein content have the potential to provide more and higher quality food for people and feed for livestock. The observed potential to contribute to grain production for protein-rich food, feed for livestock and green manure for soil N improvement suggests lablab may be an acceptable legume option for use in cereal-legume-livestock systems in the moist savanna zone of West Africa.