Absorption and utilization of N has been shown to be affected by the N form supplied and cultivar used. The relative absorption and utilization of NH4+−N and NO3−−N by triticale (X Triticosecale, Wittmack), wheat (Triticum aestivum L.), and rye (Secale cereale L.) have not been determined. This study was conducted to determine the growth and mineral composition of triticale 6TA 131, ‘Arthur’ wheat, and ‘Abruzzi’ rye grown in nutrient solutions containing different NH4+−N/N03−−N ratios in a growth chamber. The NH4+−N/NO3−−N ratios were 0/100, 25/75, 50/50, 75/25, and 100/0. Solutions were sampled every 10 days during a 30‐day plant growth period. Triticale and rye more preferentially absorbed N03−−N over NH4+−N than wheat which sometimes (50/50) absorbed more NO3 than NH4. All species produced higher dry matter with the combinations of 25/75, 50/50, and 75‐25 NH4+−N/NO3−−N ratios than with either N source alone. There were increases in the uptake of N, P, and Fe when NH4+−N/NO3−−N ratio was increased in the mixture whereas NO3−−N increased the uptake of Mg, Ca, Mn, and NO3−−N. These results suggested that the triticale inherited its absorption efficiency of NO3− from rye.

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Triticales (X Triticosecale, Wittmack), 6TA 131, 6TA 298 and 6TA 298 and 6TA 385, Arthur wheat (Triticum aestivum L.), and Abruzzi rye (Secale cereale L.) were grown in a soil treated with 0, 50, 100, and 200 ppm N. The objective of this study was to determine the influence of N rate on dry matter yields, N uptake, and N utilization efficiency. The dry matter and N uptake increased while the N utilization efficiency decreased with increasing N fertilizer applied to the soil for all the cultivars. At high N rate, rye had higher dry matter and N uptake than the triticales and wheat; no consistent differences were obtained between triticale and wheat. However, rye and triticale tended to be more efficient in utilizing absorbed N than wheat at the lower N rates. Soil was collected from the 15-30 cm layer of a virgin Hartsells sandy loam {Typic Hapudult) at Huntsville, Alabama. The soil had a pH of 4.7 in a 1:1 soil to water suspension. It had 3.38% total organic matter and 0.16%N. Bulklots of the soil were mixed with lime to bring the pH to 5.7, watered to filled capacity, and equilibrated for three days. The soil was then air dried and the wetting and drying cycle repeated two times before a 5 kg sample was placed in each pot, moistened to field capacity, and fertilized with 100 ppm P, 89 ppm K, and 5 ppm Fe on dry soil basis. Ten seedlings of triticales "6TA 131', '6TA 298', 'AM 2149' and locally grown 'Arthur' wheat, and 'Abruzzi' rye were grown in each pot. For each cultivar, NH^NOg was applied to the soil in solution at the rate of 0, 50, 100, and 200 ppm N. Each treatment was replicated three times. The greenhouse temperature was approximately 27C during the day and 21C at night. Supplemental lighting was provided to extend the light period to 16 hours per day. After each of the two harvests, plant samples were dried at 70C, weighed, and ground to pass through a 40-mesh stainless steel screen. Total N concentration was determined by the MicroKjeldal method. Nitrogen utilization efficiency ratio (NER was expressed as mg of dry weight produced per mg of N absorbed by the plant, according to the method of O'Sullivan, Gabelman and Gerloff .