Protein, Oil, and Energy Yields of Sunflower as Affected by N and P Fertilization1
- F. P. C. Blamey and
- J. Chapman2
Relatively little information exists on the N and P needs of sunflower (Helianthus annuus L.) on infertile soils in non-traditional production areas. The effects of four levels each of N (0 to 180 kg/ha) and P (0 to 60 kg/ha) applied to a thermic Typic Rhodustult were evaluated over three seasons. In all seasons there were highly significant seed yield responses to N and P a plied. The nature of the N ✕ P interactions indicated a greater response to N fertilization where P had been applied than in the absence of P fertilization. Maximum seed yields of up to 2,600 kg/ha were four to 13 fold higher than yields in the absence of applied N and P. Protein level in the seed was increased by N but decreased by P fertilization, the opposite effects being generally observed with respect to the oil. Nitrogen and P fertilization markedly increased the protein and oil yields, the N ✕ P interactions indicating that P fertilization was necessary for maximum response to applied N. The ratio of seed N to fertilizer N decreased with increased N fertilization but increased with increased P applied. The food energy yield and energy production efficiency of sunflower increased markedly with both N and P fertilization.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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