Water use, energy balance and growth of maize at Samaru, northern Nigeria

Abstract

Energy and water budget of maize crop grown in a dry sub-humid climate of northern Nigeria were assessed and related to crop performance.The pattern of crop water requirement during the growing season was well matched to the pattern of crop water availability.The period of maximum water requirement by the crop occurred when the leaf area index was greater than 2.1 and coincided with the period when the amount and frequency of rainfall was greatest. However, under the prevailing climatic conditions, with potential evapotranspiration rates of 4–6 mm per day, the crop may experience water stress, if there is no rain for a period of 5 days or more. The rate of crop growth was drastically reduced when soil-water potential decreased below −0.5 bar.The total water used by the crop during 117 days from sowing to harvest was 486 mm, of which 345 mm transpired through the plants. Crop water use efficiency was 353 g of water per gram of dry matter.The crop yielded 7,284 kg ha−1 of grain and 19,180 kg ha−1 of total dry matter. The efficiency of energy conversion for the season was 1.4% of the total incident radiation, while during the period of active growth the energy conversion was 2.4%.