Effect of different phosphorus levels on phosphorus nutrient uptake,transformation and phosphorus utilization efficiency of oil flax

The effects of phosphorus fertilization level on the phosphorus nutrient uptake,transformation,distribution and phosphorus utilization efficiency of oil flax( Baxuan No. 3) during two growing seasons( 2011 and 2012) were studied in a randomized complete block design with three replications. Four levels of phosphorus fertilization were: none, low( 35 kg / ha),medium( 70 kg / ha),and high( 105 kg / ha). Different phosphorus application rates affected phosphorus nutrient uptake,transformation and accumulation at different growth stages,and the changes were very similar. At the seedling stage,phosphorus accumulation increased daily and following phosphorus application it accumulated in stems,leaves,non-grains and grains in oil flax,but with increasing daily differences in different organs in contrast to treatment without phosphorus fertilizer application. The phosphorus transferred from leaf to grain in oil flax was an increase of 54. 93%-73. 83% and 8. 19%-10. 00%( P 0. 05) with medium phosphorus application compared with low and high phosphorus applications,respectively. The 20. 46%-35. 93% of phosphorus accumulation in grains were transferred from leaves. The phosphorus accumulation was mainly focused on reproduction development stages and the proportion was 79. 02%-92. 17% at all growth stages in oil flax plants. With a 70 kg / ha phosphorus( P 2 O 5) application rate,the maximum phosphorus fertilizer recovery efficiency and agronomic efficiency were 20. 22%-20. 53% and 7. 30-7. 44 kg / kg,respectively. The grain yield improved with increased phosphorus application and ranged from 28. 96% to 31. 46%. Based on synthesized grain yield,phosphorus fertilizer recovery efficiency,phosphorus agronomic efficiency and environmental pollution,the recommendation of phosphorus fertilizer for oil flax is 70 kg / ha( P 2 O 5) under the climatic conditions of the experimental area.