Effect of Phosphorus and Nitrogen Fertilization on Sunflower (Helianthus annus L.) Nitrogen Uptake and Yield

Abstract

Little is known about the effect of combined phosphorus and nitrogen (P-N) fertilization on the N requirement of sunflower (Helianthus annus L.). This study was carried out to evaluate the effects of varying levels of P and N, as well as the interaction P · N, on the N uptake, yield and N apparent utilization efficiency under field conditions. Splitplot design experiments were conducted in the mid-western Pampas in Argentina. Four levels of N (0, 46, 92 and 138 kg N ha )1 ) and three levels of P (0, 12 and 40 kg P ha )1 ) were applied to two Typic Hapludolls over two growing seasons (1997-98 and 1998-99). N uptake and soil N-NO 3 contents were determined at the V 7 , R 5 and R 9 growth stages. The sunflower yield ranged from 2.5 to 5.0 Mg ha )1 . The total N requirement was around 45 kg N Mg )1 grain, and this result suggests that it is not necessary to use different N requirements (parameter b) for fertilized crops when a yield response is expected. To achieve a 100 % yield maximum a N supply (soil plus fertilizer) of 181 kg N ha )1 at P 40 was needed. However, at P 0 , the highest yield was about 80 % of the maximum yield with a N supply (soil plus fertilizer) of 164 kg N ha )1 . P application increased the apparent use efficiency of the supplied N.

Cottonseed yield and its quality as affected by mineral fertilizers and plant growth retardants

“…Similar results were obtained by Froment et al [85], in linseed; Zubillaga et al [99] in sunflower. Yield increases in this study were attributed to the fact that N was an important nutrient in controlling new growth, thus influencing boll development, increasing the number of bolls plant −1 and boll weight.…”

OILCROP-SUN Model for Nitrogen Management of Diverse Sunflower (<i>Helianthus annus</i> L.) Hybrids Production under Agro-Climatic Conditions of Sargodha, Pakistan

“…Then each sample was taken every 10 days interval. The every fifteen days of interval take 10 g sample of leaves from each treatments by using area meter (JVC Model TK-S310EG) for the measurement of leaf area and dry weights were recorded at each harvesting stage are explained by [13]. When crop reached maturity, back of head has turned from green to yellow and color of brackets changed to brown.The harvesting was done by mechanically, ten plants were taken from each treated plots for determine number of achene −2 , achene yield and total dry matter.…”

The Quality of Sunflower Seed Oil Changes in Response to Nitrogen Fertilizer

“…Among the factors responsible for increasing crop yield and quality, fertilizer use is one of the most important (Reddy et al, 2003). Of all the nutrients in fertilizer, N is the most important for enhancing metabolic processes based on proteins and leads to increases in vegetative growth, reproductive growth, and yield of the crop (Zubillaga et al, 2002;Koutroubas et al, 2008). Sunfl ower responds well to applied N (Chakor and Sharma, 1994), and the fatty acid composition of sunfl ower seed oil in fi ve cultivars can be improved by manipulating the N supply rate and the time of N application in both glasshouse and fi eld experiments (Steer and Seiler, 1990).…”